Water-tube boilers and auxiliary installations - Part 7: Requirements for equipment for the boiler

This part of this European Standard specifies the essential requirements for equipment and protective devices for a water-tube boiler plant as defined in EN 12952-1, to ensure the boiler operates safely within the allowable limits (pressure, temperature, etc.).

Wasserrohrkessel und Anlagenkomponenten - Teil 7: Anforderungen an die Ausrüstung für den Kessel

Dieser Teil der vorliegenden Europäischen Norm legt Mindestanforderungen an geeignete Schutzein-richtungen für die in EN 12952 1 beschriebenen Wasserrohrkessel fest, die sicherstellen, dass der Kessel innerhalb der zulässigen Grenzen (Druck, Temperatur usw.) sicher arbeitet.

Chaudières à tubes d'eau et installations auxiliaires - Partie 7: Exigences pour l'équipement de la chaudière

Cette partie de la présente Norme européenne spécifie les prescriptions minimales auxquelles doivent répondre les dispositifs de protection appropriés des chaudières à tubes d’eau telles que définies dans l’EN 12952-1, afin de s’assurer que la chaudière fonctionne en toute sécurité dans le cadre des limites autorisées (pression, température, etc.).

Vodocevni kotli in pomožne napeljave - 7. del: Zahteve za opremo kotla

Ta del evropskega standarda določa osnovne zahteve za opremo in zaščitne naprave za vodocevne kotle, kot je določeno v standardu EN 12952-1, kar zagotavlja varno delovanje kotla v dovoljenih mejah (tlak, temperatura itd.).

General Information

Status
Published
Public Enquiry End Date
19-Aug-2010
Publication Date
13-Nov-2012
Technical Committee
Current Stage
6100 - Translation of adopted SIST standards (Adopted Project)
Start Date
24-Oct-2019
Due Date
22-Oct-2020
Completion Date
25-Sep-2020

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Vodocevni kotli in pomožne napeljave - 7. del: Zahteve za opremo kotlaWasserrohrkessel und Anlagenkomponenten - Teil 7: Anforderungen an die Ausrüstung für den KesselChaudières à tubes d'eau et installations auxiliaires - Partie 7: Exigences pour l'équipement de la chaudièreWater-tube boilers and auxiliary installations - Part 7: Requirements for equipment for the boiler27.060.30Grelniki vode in prenosniki toploteBoilers and heat exchangersICS:Ta slovenski standard je istoveten z:EN 12952-7:2012SIST EN 12952-7:2012en,fr,de01-december-2012SIST EN 12952-7:2012SLOVENSKI
STANDARDSIST EN 12952-7:20021DGRPHãþD



SIST EN 12952-7:2012



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12952-7
October 2012 ICS 27.040 Supersedes EN 12952-7:2002English Version
Water-tube boilers and auxiliary installations - Part 7: Requirements for equipment for the boiler
Chaudières à tubes d'eau et installations auxiliaires - Partie7: Exigences pour l'équipement de la chaudière
Wasserrohrkessel und Anlagenkomponenten - Teil 7: Anforderungen an die Ausrüstung für den Kessel This European Standard was approved by CEN on 8 September 2012.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12952-7:2012: ESIST EN 12952-7:2012



EN 12952-7:2012 (E) 2 Contents Foreword . 31Scope . 52Normative references . 53Terms and definitions . 64General requirements for steam boilers and hot water generators . 85Special requirements for steam boilers . 126Special requirements for hot water generators . 157Additional requirements for plants without manual intervention . 208Final inspection of the water tube boiler plant . 23Annex A (normative)
Chemical recovery boilers (Black liquor recovery boilers) . 24Annex B (informative)
Aspects of boiler operation . 26Annex C (informative)
Alarms and monitoring from the boiler plant . 30Annex D (normative)
Requirements for limiters based on analogue measurements . 31Annex E (normative)
Access to internal parts . 35Annex F (normative)
Final inspection of the water tube boiler plant . 38Annex G (informative)
Drain and blowdown devices . 39Annex H (informative)
Significant technical changes between this European Standard and the
previous edition . 40Annex ZA (informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 97/23/EC . 41Bibliography . 42
SIST EN 12952-7:2012



EN 12952-7:2012 (E) 3 Foreword This document (EN 12952-7:2012) has been prepared by Technical Committee CEN/TC 269 “Shell and water-tube boilers”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2013, and conflicting national standards shall be withdrawn at the latest by April 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 12952-7:2002. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive 97/23/EC, see informative Annex ZA, which is an integral part of this document. Annex H provides details of significant technical changes between this European Standard and the previous edition. The European Standard series EN 12952 concerning water-tube boilers and auxiliary installations consists of the following parts:  Part 1: General;  Part 2: Materials for pressure parts of boilers and accessories;  Part 3: Design and calculation for pressure parts of the boiler;  Part 4: In-service boiler life expectancy calculations;  Part 5: Workmanship and construction of pressure parts of the boiler;  Part 6: Inspection during construction, documentation and marking of pressure parts of the boiler;  Part 7: Requirements for equipment for the boiler;  Part 8: Requirements for firing systems for liquid and gaseous fuels for the boiler;  Part 9: Requirements for firing systems for pulverized solid fuels for the boiler;  Part 10: Requirements for safeguards against excessive pressure;  Part 11: Requirements for limiting devices of the boiler and accessories;  Part 12: Requirements for boiler feedwater and boiler water quality;  Part 13: Requirements for flue gas cleaning systems;  Part 14: Requirements for flue gas DENOX-systems using liquified pressurized ammonia and ammonia water solution; SIST EN 12952-7:2012



EN 12952-7:2012 (E) 4  Part 15: Acceptance tests;  Part 16: Requirements for grate and fluidized-bed firing systems for solid fuels for the boiler;  CR 12952 Part 17: Guideline for the involvement of an inspection body independent of the manufacturer;  Part 18: Operating instructions. Although these parts may be obtained separately, it should be recognised that the parts are inter-dependent. As such, the design and manufacture of water-tube boilers requires the application of more than one part in order for the requirements of this European Standard to be satisfactorily fulfilled. NOTE 1 Part 4 and Part 15 are not applicable during the design, construction and installation stages. NOTE 2 A "Boiler Helpdesk" has been established in CEN/TC 269 which may be contacted for any questions regarding the application of European Standards series EN 12952 and EN 12953, see the following website: http://www.boiler-helpdesk.din.de
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
SIST EN 12952-7:2012



EN 12952-7:2012 (E) 5 1 Scope This part of this European Standard specifies the essential requirements for equipment and protective devices for a water-tube boiler plant as defined in EN 12952-1, to ensure the boiler operates safely within the allowable limits (pressure, temperature, etc.). NOTE 1 Additional requirements specially needed for boilers without manual intervention are specified in Clause 7. NOTE 2 Requirements for equipment for chemical recovery boilers are given in Annex A. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispen-sable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 837-1, Pressure gauges — Part 1: Bourdon tube pressure gauges — Dimensions, metrology, requirements and testing EN 12952-1:2001, Water-tube boilers and auxiliary installations
Part 1: General EN 12952-3:2011, Water-tube boilers and auxiliary installations
Part 3: Design and calculation for pressure parts of the boiler EN 12952-8:2002, Water-tube boilers and auxiliary installations
Part 8: Requirements for firing systems for liquid and gaseous fuels for the boiler EN 12952-9:2002, Water-tube boilers and auxiliary installations
Part 9: Requirements for firing systems for pulverized solid fuels for the boiler EN 12952-10:2002, Water-tube boilers and auxiliary installations
Part 10: Requirements for safeguards against excessive pressure EN 12952-11:2007, Water-tube boilers and auxiliary installations
Part 11: Requirements for limiting devices of the boiler and accessories EN 12952-12:2003, Water-tube boilers and auxiliary installations
Part 12: Requirements for boiler feedwater and boiler water quality EN 12952-13, Water-tube boilers and auxiliary installations
Part 13: Requirements for flue gas cleaning systems EN 12952-14, Water-tube boilers and auxiliary installations
Part 14: Requirements for flue gas DENOX-systems using liquefied pressurized ammonia and ammonia water solution EN 12952-16:2002, Water-tube boilers and auxiliary installations
Part 16: Requirements for grate and fluidized-bed firing systems for solid fuels for the boiler EN 12952-18, Water-tube boilers and auxiliary installations
Part 18: Operating instructions EN 50156-1:2004, Electrical equipment for furnaces and ancillary equipment — Part 1: Requirements for application design and installation SIST EN 12952-7:2012



EN 12952-7:2012 (E) 6 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12952-1:2001, EN 12952-8:2002, EN 12952-9:2002, EN 12952-11:2007, EN 12952-12:2003 and EN 12952-16:2002 and the following apply. 3.1 Types of steam boilers and hot water generators
3.1.1 natural circulation steam boilers and hot water generators steam boilers and hot water generators in which the water to be evaporated/heated circulates due to the differences in density
3.1.2 forced or assisted circulation steam boilers and hot water generators steam boilers and hot water generators in which the water to be evaporated/heated is circulated by means of pumps 3.1.3 once-through steam boilers and hot water generators steam boilers, with or without separating vessels, where the water flow is determined by the feedwater pump, and the water is evaporated completely or in a major portion during one single passage Note 1 to entry: Hot water generators, where the water flow is effected by the circulating pump of the heating system and is heated during one single passage, e.g. once-through hot water generator where there is no contact between hot and cold water in the drum (two-way drum) once-through hot water generator with header distributing water from below. 3.1.4 waste heat steam boilers and hot water generators boilers and generators utilising heat recovered from outside sources, e.g. gas turbines, blast furnaces 3.2 limits of steam boilers and hot water generators boundaries of the steam and water spaces located between the shut-off devices of the steam boilers and hot water generators in the inlet, outlet, pressure retaining, overflow, and drain lines Note 1 to entry: The bodies of the shut-off devices are considered to be within these limits. 3.3 steam boiler and hot water generating plant plant consists of one or more water-tube boilers and their equipment as defined in EN 12952-1 3.4 heat supply system assembly of components in which the energy of the fuel (including electrical and waste-heat energy) is supplied to the steam boilers and hot water generators 3.5 classification of pressure generation systems (Hot water generators)
3.5.1 internally pressurised systems systems where the pressure is generated by the saturation pressure corresponding to the flow temperature
3.5.2 externally pressurised systems systems where the pressure is generated by methods such as gas cushion or pressure pumps SIST EN 12952-7:2012



EN 12952-7:2012 (E) 7 3.6 expansion vessels containers to compensate for temperature related changes in water volume
 closed expansion vessels are pressurised  open expansion vessels are vented to atmospheric pressure and are not pressurised 3.7 maximum continuous rating (MCR) maximum continuous steam output that can be generated during continuous operation
3.8 allowable heat output maximum heat output (water mass flow times the difference between outlet and inlet enthalpy) that can be generated during continuous operation and at which hot water generators may be operated 3.9 maximum allowable pressure (PS) maximum pressure for which equipment is designed, as specified by the manufacturer, and at a location specified by the manufacturer Note 1 to entry: This may be the location of connection of protective and/or limiting devices or the top of equipment or, if not applicable, any point specified. 3.10 maximum allowable temperature (TS) maximum temperature of the fluid for which equipment is designed by the manufacturer, and at a location specified by the manufacturer
Note 1 to entry: Typically, this is at the outlet of the generator. 3.11 controls devices used for holding the variable to be controlled (e.g. water level, pressure, temperature) at a specified value (set point) 3.12 limiter limiting device that, on reaching a fixed value (e.g. pressure, temperature, flow, water level) is used to interrupt and lock-out the heat supply and requires manual unlocking before restart Limiting device requires:  a measuring or detection function, and  an activation function for correction, or shutdown, or shutdown and lockout, and which is used to carry out safety related functions as defined in the Pressure Equipment Directive (PED) 97/23/EC [1], either on its own or as part of a protective system (e.g. sensors, limiters, etc.) (see also Figure 1). If this is achieved by multi-channel systems, then all items or limiters for safety purposes are included within the protective system. Note 1 to entry: Manual resetting can be realised as a part of the limiter or as a part of the safety logic. This will be achieved by the responsible operator taking into account the physical situation. Note 2 to entry: For limiters based on on analogue measurements, see Annex D. SIST EN 12952-7:2012



EN 12952-7:2012 (E) 8
Figure 1 — Protective devices and safety accessories according to the Directive 97/23/EC (PED) 3.13 independent ability to function as required without interference from other equipment 3.14 reliability ability to perform a required function under specified conditions and for a given period of time without failing 3.15 functional check
testing of the safety device to ensure it performs its intended function
3.16 boiler attendant boiler operator
skilled person appointed for operating the boiler plant 3.17 normal shut down controlled switch-off of the boiler operated either manually or automatically
3.18 normal operation operation, with all regulating circuits and controls (open loops/closed loops) in normal mode and with the set points and parameters valid for normal operation. For operation without manual intervention, all regulating circuits and controls (open loops/closed loops) are in automatic mode Note 1 to entry: Normal operation also includes the automatic switching-on and switching-off of the assigned actuators (e.g. burner). 3.19 lock-out safety shutdown condition of the protective system, such that a restart can only be accomplished by a manual reset of the limiter or by a manual reset of the safety logic by the boiler attendant and by no other means 4 General requirements for steam boilers and hot water generators 4.1 Safeguards against excessive pressure Each steam boiler, hot water generator and each isolatable heated compartment shall be equipped with safeguards against excessive pressure in accordance with EN 12952-10.
SIST EN 12952-7:2012



EN 12952-7:2012 (E) 9 4.2 Heat supply system 4.2.1 The requirements for heat supply to steam boilers and hot water generators shall be in accordance with:
 EN 12952-8 for firing systems for liquid and gaseous fuels;  EN 12952-9 or EN 12952-16 for solid fuels. 4.2.2 The heat supply shall be adapted to the allowable heat output as well as to the intended mode of operation. The heat supply shall be controlled and in all operating stages adapted to the variation of the heat demand.
4.2.3 In the event of normal shutdown or lock out, residual heat accumulated in the furnace and flue-gas passes shall not cause unacceptable metal or fluid temperatures (e.g. by evaporation of the water) in the steam boiler/hot water generator. This requirement is fulfilled:
 if it is proved that, after interruption of the heat supply from the full load steady state condition, the flue-gas temperature at the highest point of the heating surface (HHS) falls to below 400 °C before the water level has sunk from the lowest permissible water level (LWL) to 50 mm above the highest point of the heating surface (HHS); or  if a reliable feedwater supply is installed to ensure adequate cooling of the heating surfaces in case of a sudden loss of essential operational parameters (see e.g. 5.1.1.2); or  by oil, gas or pulverised fuel firing systems (except slag-tap firing or heavy brickwork in the furnace or flue-gas passes); or  if it is only heated with gases not exceeding a temperature of 400 °C. 4.3 Ash removal plants Ash removal plant shall be in accordance with EN 12952-9 or EN 12952-16. 4.4 Flue-gas cleaning plants Flue-gas cleaning plants shall be in accordance with EN 12952-13 and EN 12952-14. 4.5 Requirements for limiting devices and protective systems 4.5.1 The protective systems shall be in accordance with EN 50156-1. Limiters and their installation shall be in accordance with Annex D or EN 12952-11. The appropriate Safety Integrity Levels (SIL) identified according to EN 50156-1 shall be implemented. 4.5.2 The application design and installation of the electrical safety circuit as well as the electrical and control equipment for the heat supply and its auxiliary equipment shall be in accordance with EN 50156-1. NOTE
If required, it should be possible to stop the boiler by additional devices outside the boiler such as shut-off valve, emergency shut-off, fire detectors, etc. 4.5.3 Functional check of all limiters shall be possible at any time during operation. Where appropriate the functional check can be performed by simulation. SIST EN 12952-7:2012



EN 12952-7:2012 (E) 10 4.5.4 When a limiter activates, information shall be given to indicate which limiter has activated.
4.5.5 For waste heat boilers or generators, when a limiter activates, the heat supply shall be interrupted and locked-out or the waste gas flow shall be diverted to bypass the steam boiler or hot water generator. The bypass shall be manually reset by the boiler attendant. NOTE If the waste gas flow is not completely diverted to the bypass within a defined time then the heat supply should be interrupted. 4.6 Feed lines and protection against feedwater backflow 4.6.1 Each feed line leading to the steam boiler or hot water generator shall be equipped with a protection device against backflow and a shut-off device. If the shut-off device and the protection device against backflow are not installed in direct connection to each other, pressure relieving shall be possible for the intermediate piping section. A single once-through steam boiler in which the heat supply is cut off automatically in the case of feedwater failure, requires neither a shut-off device nor protection device against backflow if the feedwater pump is of the positive displacement type where it can be ensured that no dangerous backflow can occur. 4.6.2 Except for once-through boilers, the feed line shall be connected to the steam boiler or hot water gen-erator in such a way that, in the case of leakage of the protection device against backflow, the steam boiler cannot be drained to below the highest point of the down comers. 4.6.3 Feedwater pumps shall be capable of isolation from common suction or pressure lines. 4.6.4 If an isolating valve is installed in the feedwater suction line, the isolating valve and the line between the isolating valve and the feed pump should be designed for the same conditions as the pressure line to the boiler or appropriate devices shall be installed to exclude the danger from overpressure if the isolating valve is closed. 4.7 Connection of steam boilers or hot water generators Where a steam boiler or hot water generating plant has several steam boilers or hot water generators connected by common lines and the shut-off devices in the steam or hot water and feed lines remain permanently connected with these lines during inspection of the steam boilers or hot water generators, two shut-off devices with intermediate venting shall be installed in each line. The shut-off devices shall be lockable in the closed position and be protected against unintentional actuation. 4.8 Water quality
4.8.1 General The water quality shall be at least in accordance with EN 12952-12 and the operating instructions. 4.8.2 Sampling
It shall be possible at any time during operation to safely take reliable samples of the boiler water, feedwater, make-up water and if relevant the condensate and/or the recirculation water.
Depending on the temperature of the media the samples shall be taken through one or more sample coolers. 4.8.3 Equipment for monitoring of the steam boiler water quality Equipment for monitoring of the steam boiler water conductivity shall be installed.
If high conductivity can compromise the safety of the boiler or the operation of any limiter, the monitoring shall be continuous. SIST EN 12952-7:2012



EN 12952-7:2012 (E) 11 If the conductivity is outside the limits given by the operating instructions or specified by EN 12952-12, appropriate corrective actions shall be taken. 4.8.4 Condensate and make-up water in steam boiler plants An assessment shall be carried out to identify if there is a risk that harmful matter (e.g. oil, grease, organic material, acid, lye, seawater, hardness, ion exchange resin etc.) can enter into the feed water system and/or into the boiler that will compromise the safety of the boiler or the operation of the limiters.
If it is assessed that this risk exists, then adequate monitoring shall be installed which is able to detect the harmful matter.
If harmful matter is detected that will compromise the safety of the boiler or the operation of the limiters, appropriate corrective actions shall be taken. NOTE If the intermediate circuit of a double circuit system is filled with softened water, it is not considered that there is a hazard that harmful matter may enter the system. 4.8.5 Water circulating system in hot water generator plants An assessment shall be carried out to identify if there is a risk that harmful matter (e.g. oil, grease, organic material, acid, lye, seawater, hardness, ion exchange resin etc.) can enter the water circulating system that will compromise the safety of the boiler or the operation of the limiters.
If it is assessed that this risk exists, then adequate monitoring shall be installed which is able to detect the harmful matter.
If harmful matter is detected that will compromise the safety of the generator or the operation of the limiters, appropriate corrective actions shall be taken. NOTE If the intermediate circuit of a double circuit system is filled with softened water, it is not considered that there is a hazard that harmful matter may enter the system. 4.9 Access to internal parts Access to internal parts for such tasks as cleaning, inspection, maintenance, shall be in accordance with Annex E. 4.10 Marking Each water-tube boiler plant shall be provided with a durably marked nameplate. The marking shall include the following: a) name and address of the manufacturer; b) serial number (unique identification); c) year of manufacture; d) maximum allowable pressure and temperature; e) maximum continuous rating (for steam boilers) or maximum heat output (for hot water generators); f) date of first hydrostatic test and test pressure, if applicable; g) number of this European Standard; h) reference number of the responsible third party organisation, if applicable; i) CE marking, if applicable. SIST EN 12952-7:2012



EN 12952-7:2012 (E) 12 5 Special requirements for steam boilers 5.1 Requirements for pumps 5.1.1 Number of feedwater pumps 5.1.1.1 One feedwater pump is sufficient if the requirements of 4.2.3, 1st, 3rd or 4th indent(s), are met. In the case of failure of the feedwater pump, e. g power source, the heat supply shall be cut off automatically. 5.1.1.2 Steam boilers that do not meet the requirements of 4.2.3, 1st, 3rd or 4th indent(s), shall be equipped with at least two feedwater pumps. If one feedwater pump fails, the heat supply shall be automatically reduced to fulfil the requirements of 4.2.3, 1st, 3rd or 4th indent(s). Otherwise the heat supply shall be cut off automatically. 5.1.2 Capacity of feedwater pumps 5.1.2.1 The steam boiler shall be provided with an adequate supply of feedwater.
The feedwater pumps shall be capable of supplying the feedwater to the steam boiler at 1,1 times the maximum allowable pressure, considering the geodetic height and the dynamic pressure losses in the feed-line and the boiler.
If it is proved that in the case of exceeding the maximum allowable pressure, the pressure relief devices are capable of discharging the steam generated at the maximum continuous rating to prevent the pressure reaching 10 % above the maximum allowable pressure a correspondingly lower factor than 1.1 can be used in the calculation. 5.1.2.2 If more than one feedwater pump is required according to 5.1.1.2, the following shall apply: a) In the case of failure of the feedwater pump with the highest capacity, the remaining feedwater pumps shall meet the requirements of 5.1.2.1; b) Two independent power sources shall be available. By exception, steam operation of all feedwater pumps from only one steam main shall be permissible. The feedwater pumps shall be connected to the power sources in such a way that in the case of failure of one power source the remaining feedwater pumps shall meet the requirements of 5.1.2.1. Where the pumps are electrically driven, one line per feedwater pump drive can suffice if the line can be switched over to a separate independent electrical supply; c) In the case of steam boiler plant of a unitised arrangement, it shall be permitted to rate the second feed-water pump for reduced capacity if it is ensured that in the case of failure of the feedwater pumps rated for the allowable steam output, the heat supply system is, at the same time, automatically adjusted to the reduced steam output. If water is blown down, the quantity of blow down water shall be fully considered when rating the second feedwater pump; d) For natural and assisted circulation steam boilers, the stand-by pump shall have been put into operation if the operating pump fails, before the water level has sunk below the lowest permissible water level (LWL, see 5.3); e) In the case of once-through steam boilers, the stand-by pump shall have been put into operation, within a time interval to be specified by the manufacturer, if the operating pump fails, or if the flow through the steam boiler has fallen to below the minimum flow required, thus ensuring that an unacceptable metal or fluid temperature is avoided. f) An alarm system shall activate in the case of failure of a feed water pump. 5.1.3 Circulating pumps 5.1.3.1 For forced circulation steam boilers one circulating pump shall suffice if in the case of failure of the circulating pump e.g. power source, the heat sup
...

SLOVENSKI STANDARD
SIST EN 12952-7:2012
01-december-2012
Nadomešča:
SIST EN 12952-7:2002
Vodocevni kotli in pomožne napeljave - 7. del: Zahteve za opremo kotla
Water-tube boilers and auxiliary installations - Part 7: Requirements for equipment for
the boiler
Wasserrohrkessel und Anlagenkomponenten - Teil 7: Anforderungen an die Ausrüstung
für den Kessel
Chaudières à tubes d'eau et installations auxiliaires - Partie 7: Exigences pour
l'équipement de la chaudière
Ta slovenski standard je istoveten z: EN 12952-7:2012
ICS:
27.060.30 Grelniki vode in prenosniki Boilers and heat exchangers
toplote
SIST EN 12952-7:2012 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 12952-7:2012

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SIST EN 12952-7:2012


EUROPÄISCHE NORM
EN 12952-7

EUROPEAN STANDARD

NORME EUROPÉENNE
Oktober 2012
ICS 27.040 Ersatz für EN 12952-7:2002
Deutsche Fassung
Wasserrohrkessel und Anlagenkomponenten - Teil 7:
Anforderungen an die Ausrüstung für den Kessel
Water-tube boilers and auxiliary installations - Part 7: Chaudières à tubes d'eau et installations auxiliaires - Partie
Requirements for equipment for the boiler 7: Exigences pour l'équipement de la chaudière
Diese Europäische Norm wurde vom CEN am 8. September 2012 angenommen.

Die CEN-Mitglieder sind gehalten, die CEN/CENELEC-Geschäftsordnung zu erfüllen, in der die Bedingungen festgelegt sind, unter denen
dieser Europäischen Norm ohne jede Änderung der Status einer nationalen Norm zu geben ist. Auf dem letzten Stand befindliche Listen
dieser nationalen Normen mit ihren bibliographischen Angaben sind beim Management-Zentrum des CEN-CENELEC oder bei jedem CEN-
Mitglied auf Anfrage erhältlich.

Diese Europäische Norm besteht in drei offiziellen Fassungen (Deutsch, Englisch, Französisch). Eine Fassung in einer anderen Sprache,
die von einem CEN-Mitglied in eigener Verantwortung durch Übersetzung in seine Landessprache gemacht und dem Management-
Zentrum mitgeteilt worden ist, hat den gleichen Status wie die offiziellen Fassungen.

CEN-Mitglieder sind die nationalen Normungsinstitute von Belgien, Bulgarien, Dänemark, Deutschland, der ehemaligen jugoslawischen
Republik Mazedonien, Estland, Finnland, Frankreich, Griechenland, Irland, Island, Italien, Kroatien, Lettland, Litauen, Luxemburg, Malta,
den Niederlanden, Norwegen, Österreich, Polen, Portugal, Rumänien, Schweden, der Schweiz, der Slowakei, Slowenien, Spanien, der
Tschechischen Republik, der Türkei, Ungarn, dem Vereinigten Königreich und Zypern.





EUROPÄISCHES KOMITEE FÜR NORMUNG
EUROPEAN COMMITTEE FOR STANDARDIZATION

COMITÉ EUROPÉEN DE NORMALISATION

Management-Zentrum: Avenue Marnix 17, B-1000 Brüssel
© 2012 CEN Alle Rechte der Verwertung, gleich in welcher Form und in welchem Ref. Nr. EN 12952-7:2012 D
Verfahren, sind weltweit den nationalen Mitgliedern von CEN vorbehalten.

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SIST EN 12952-7:2012
EN 12952-7:2012 (D)
Inhalt
Seite
Vorwort .4
1 Anwendungsbereich .6
2 Normative Verweisungen .6
3 Begriffe .7
4 Allgemeine Anforderungen an Dampf- und Heißwassererzeuger .9
4.1 Sicherheitseinrichtungen gegen Überdruck .9
4.2 Beheizungssystem . 10
4.3 Entaschungsanlagen . 10
4.4 Rauchgasreinigungsanlagen . 10
4.5 Anforderungen an Begrenzungseinrichtungen und Schutzsysteme . 10
4.6 Speiseleitungen und Sicherung gegen Rückströmen des Speisewassers . 11
4.7 Verbindung von Dampf- oder Heißwassererzeugern . 11
4.8 Wasserqualität . 11
4.9 Zugang zu inneren Bauteilen . 12
4.10 Kennzeichnung . 12
5 Zusätzliche Anforderungen an Dampferzeuger . 13
5.1 Anforderungen an Pumpen . 13
5.2 Absperr- und Entleerungseinrichtungen . 14
5.3 Niedrigster zulässiger Wasserstand (NW) . 14
5.4 Wasserstand- und Strömungs-Anzeigeeinrichtungen . 15
5.5 Wassermangelsicherung . 16
5.6 Druckanzeiger . 16
5.7 Überwachung und Reglung der Temperatur des Überhitzers . 16
6 Zusätzliche Anforderungen an Heißwassererzeuger . 16
6.1 Anforderungen an Heißwassererzeugungsanlagen . 16
6.2 Anforderungen an Pumpen . 17
6.3 Absperr- und Entleerungseinrichtungen . 18
6.4 Niedrigster zulässiger Wasserstand und Einführung der Vor- und Rücklaufleitung . 19
6.5 Wasserstand- und Strömungs-Anzeigeeinrichtungen . 19
6.6 Schutzeinrichtung gegen Wassermangel . 20
6.7 Schutzeinrichtungen gegen Unterschreitung des Mindestdrucks . 21
6.8 Schutzeinrichtungen gegen Temperaturüberschreitung . 21
6.9 Druck- und Temperatur-Anzeigegeräte . 21
7 Zusätzliche Anforderungen an Anlagen ohne manuellen Eingriff . 22
7.1 Allgemeines . 22
7.2 Wärmezufuhr . 22
7.3 Anfahren . 22
7.4 Wasserqualität . 23
7.5 Dampferzeuger . 23
7.6 Heißwassererzeuger . 24
7.7 Warneinrichtungen und Überwachung der Wasserrohrkesselanlage . 24
8 Abschließende Prüfung der Wasserrohrkesselanlage . 24
Anhang A (normativ) Laugenrückgewinnungskessel (Schwarzlaugenkessel) . 25
Anhang B (informativ) Betrachtungen zum Kesselbetrieb . 27
Anhang C (informativ) Warneinrichtungen und Überwachung für eine Kesselanlage . 31
Anhang D (normativ) Anforderungen an Begrenzer, die auf analogen Messungen basieren . 32
2

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Seite
Anhang E (normativ) Zugang zu inneren Bauteilen . 36
Anhang F (normativ) Abschließende Prüfung der Wasserrohrkesselanlage . 39
Anhang G (informativ) Entleerungs- und Ausblaseinrichtungen. 40
Anhang H (informativ) Wesentliche technische Änderungen zwischen dieser Europäischen Norm
und der vorherigen Ausgabe . 42
Anhang ZA (informativ) Zusammenhang zwischen dieser Europäischen Norm und den
grundlegenden Anforderungen der EU-Richtlinie 97/23/EG . 43
Literaturhinweise . 44


3

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SIST EN 12952-7:2012
EN 12952-7:2012 (D)
Vorwort
Dieses Dokument (EN 12952-7:2012) wurde vom Technischen Komitee CEN/TC 269 „Großwasserraum- und
Wasserrohrkessel“ erarbeitet, dessen Sekretariat vom DIN gehalten wird.
Diese Europäische Norm muss den Status einer nationalen Norm erhalten, entweder durch Veröffentlichung
eines identischen Textes oder durch Anerkennung bis April 2013, und etwaige entgegenstehende nationale
Normen müssen bis April 2013 zurückgezogen werden.
Es wird auf die Möglichkeit hingewiesen, dass einige Texte dieses Dokuments Patentrechte berühren können.
CEN [und/oder CENELEC] sind nicht dafür verantwortlich, einige oder alle diesbezüglichen Patentrechte zu
identifizieren.
Dieses Dokument ersetzt EN 12952-7:2002.
Dieses Dokument wurde unter einem Mandat erarbeitet, das die Europäische Kommission und die
Europäische Freihandelszone dem CEN erteilt haben, und unterstützt grundlegende Anforderungen der
EU-Richtlinien.
Zum Zusammenhang mit EU-Richtlinie 97/23/EG siehe informativen Anhang ZA, der Bestandteil dieses
Dokuments ist.
Anhang H enthält Einzelheiten zu den maßgebenden technischen Änderungen zwischen dieser Europäischen
Norm und der vorherigen Ausgabe.
Die Europäische Normserie EN 12952 Wasserkessel und Anlagenkomponenten" besteht aus folgenden
Teilen:
 Teil 1: Allgemeines;
 Teil 2: Werkstoffe für drucktragende Kesselteile und Zubehör;
 Teil 3: Konstruktion und Berechnung für drucktragende Kesselteile;
 Teil 4: Betriebsbegleitende Berechnung der Lebensdauererwartung;
 Teil 5: Verarbeitung und Bauausführung für drucktragende Kesselteile;
 Teil 6: Prüfung während der Fertigung, Dokumentation und Kennzeichnung für drucktragende Kesselteile;
 Teil 7: Anforderungen an die Ausrüstung für den Kessel;
 Teil 8: Anforderungen an Feuerungsanlagen für flüssige und gasförmige Brennstoffe für den Kessel;
 Teil 9: Anforderungen an Staubfeuerungsanlagen für den Kessel;
 Teil 10: Anforderungen an Sicherheitseinrichtungen gegen Drucküberschreitung;
 Teil 11: Anforderungen an Begrenzungseinrichtungen an Kessel und Zubehör;
 Teil 12: Anforderungen an die Speisewasser- und Kesselwasserqualität;
 Teil 13: Anforderungen an Rauchgasreinigungsanlagen;
 Teil 14: Anforderungen an Rauchgas-DENOX-Anlagen, die flüssiges Ammoniak und Ammoniak-
wasserlösung einsetzen;
 Teil 15: Abnahmeversuche;
 Teil 16: Anforderungen an Rost- und Wirbelschichtfeuerungsanlagen für feste Brennstoffe für den Kessel;
 CR 12952, Teil 17: Leitfaden für die Einbeziehung einer herstellerunabhängigen Prüforganisation;
 Teil 18: Betriebsanleitungen.
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SIST EN 12952-7:2012
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Obwohl diese Teile einzeln zu erwerben sind, sollte bedacht werden, dass sie voneinander abhängig sind.
Deshalb werden für die Konstruktion und Herstellung von Wasserrohrkesseln mehrere Teile benötigt, um die
Anforderungen der Europäischen Norm zufrieden stellend zu erfüllen.
ANMERKUNG 1 Die Teile 4 und 15 sind nicht während der Konstruktion, Fertigung und Errichtung anzuwenden.
ANMERKUNG 2 Für sämtliche Fragen zur Anwendung der Europäischen Normenreihen EN 12952 und EN 12953 wurde
ein „Boiler Helpdesk“ im CEN/TC 269 eingerichtet, siehe die folgende Webseite: http://www.boiler-helpdesk.din.de
Entsprechend der CEN/CENELEC-Geschäftsordnung sind die nationalen Normungsinstitute der folgenden
Länder gehalten, diese Europäische Norm zu übernehmen: Belgien, Bulgarien, Dänemark, Deutschland, die
ehemalige jugoslawische Republik Mazedonien, Estland, Finnland, Frankreich, Griechenland, Irland, Island,
Italien, Kroatien, Lettland, Litauen, Luxemburg, Malta, Niederlande, Norwegen, Österreich, Polen, Portugal,
Rumänien, Schweden, Schweiz, Slowakei, Slowenien, Spanien, Tschechische Republik, Türkei, Ungarn,
Vereinigtes Königreich und Zypern.
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SIST EN 12952-7:2012
EN 12952-7:2012 (D)
1 Anwendungsbereich
Dieser Teil der vorliegenden Europäischen Norm legt die wesentlichen Anforderungen an Ausrüstung und
Schutzeinrichtungen für die in EN 12952-1 festgelegten Wasserrohrkesselanlagen fest, die sicherstellen, dass
der Kessel innerhalb der zulässigen Grenzen (Druck, Temperatur usw.) sicher arbeitet.
ANMERKUNG 1 Zusätzliche Anforderungen, die besonders bei Kesseln ohne manuellen Eingriff benötigt werden, sind
in Abschnitt 7 festgelegt.
ANMERKUNG 2 Anforderungen an die Ausrüstung für Laugenrückgewinnungskessel sind in Anhang A angegeben.
2 Normative Verweisungen
Die folgenden Dokumente, die in diesem Dokument teilweise oder als Ganzes zitiert werden, sind für die
Anwendung dieses Dokuments erforderlich. Bei datierten Verweisungen gilt nur die in Bezug genommene
Ausgabe. Bei undatierten Verweisungen gilt die letzte Ausgabe des in Bezug genommenen Dokuments
(einschließlich aller Änderungen).
EN 837-1, Druckmessgeräte — Teil 1: Druckmessgeräte mit Rohrfedern — Maße, Messtechnik, Anfor-
derungen und Prüfung
EN 12952-1:2001, Wasserrohrkessel und Anlagenkomponenten — Teil 1: Allgemeines
EN 12952-3:2011, Wasserrohrkessel und Anlagenkomponenten — Teil 3: Konstruktion und Berechnung für
drucktragende Teile
EN 12952-8:2002, Wasserrohrkessel und Anlagenkomponenten — Teil 8: Anforderungen an Feuerungs-
anlagen für flüssige und gasförmige Brennstoffe für den Kessel
EN 12952-9:2002, Wasserrohrkessel und Anlagenkomponenten — Teil 9: Anforderungen an Staubfeuerungs-
anlagen für den Kessel
EN 12952-10:2002, Wasserrohrkessel und Anlagenkomponenten — Teil 10: Anforderungen an Sicherheits-
einrichtungen gegen Drucküberschreitung
EN 12952-11:2007, Wasserrohrkessel und Anlagenkomponenten — Teil 11: Anforderungen an Begrenzungs-
einrichtungen an Kessel und Zubehör
EN 12952-12:2003, Wasserrohrkessel und Anlagenkomponenten — Teil 12: Anforderungen an die
Speisewasser- und Kesselwasserqualität
EN 12952-13, Wasserrohrkessel und Anlagenkomponenten — Teil 13: Anforderungen an Rauchgas-
reinigungsanlagen
EN 12952-14, Wasserrohrkessel und Anlagenkomponenten — Teil 14: Anforderungen an Rauchgas-DENOX-
Anlagen, die flüssiges Ammoniak und Ammoniakwasserlösung einsetzen
EN 12952-16:2002, Wasserrohrkessel und Anlagenkomponenten — Teil 16: Anforderungen an Rost- und
Wirbelschichtfeuerungsanlagen für feste Brennstoffe für den Kessel
EN 12952-18, Wasserrohrkessel und Anlagenkomponenten — Teil 18: Betriebsanleitungen
EN 50156-1:2004, Elektrische Ausrüstung für Feuerungsanlagen — Teil 1: Bestimmungen für Anwendungs-
planung und Errichtung
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3 Begriffe
Für die Anwendung dieses Dokuments gelten die Begriffe nach EN 12952-1:2001, EN 12952-8:2002,
EN 12952-9:2002, EN 12952-11:2007, EN 12952-12:2003 und EN 12952-16:2002 und die folgenden Begriffe.
3.1
Bauarten von Dampf- und Heißwassererzeugern
3.1.1
Naturumlauf-Kessel
Dampf- und Heißwassererzeuger, in denen das zu verdampfende bzw. erwärmende Wasser aufgrund des
Dichteunterschieds (Schwerkraft) zirkuliert
3.1.2
Zwangumlauf-Kessel
Dampf- und Heißwasserkessel, in denen das zu verdampfende bzw. erwärmende Wasser mit Pumpen umge-
wälzt wird
3.1.3
Zwangdurchlauf-Kessel
Dampfkessel ohne oder mit Abscheidebehältern, bei denen der Durchlauf des Wassers von der Speise-
wasserpumpe veranlasst wird und das Wasser bei einmaligem Durchlauf ganz oder größtenteils verdampft
wird
Anmerkung 1 zum Begriff: Heißwassererzeuger, in denen das Wasser durch die Umwälzpumpe des Heizungssystems
durchgesetzt und bei einmaligem Durchlauf erwärmt wird, z. B. Durchlauf-Heißwassererzeuger mit Trennung von Wasser
und Dampf in der Trommel (Zwei-Wege-Trommel) oder Durchlauf-Heißwassererzeuger mit unterer Verteilung von Wasser
3.1.4
Abhitze-Dampf- und Heißwassererzeuger
Kessel zur Nutzung der Abwärme aus externen Quellen, z. B. Gasturbinen, Hochöfen
3.2
Betriebsgrenzen von Dampf- und Heißwassererzeugern
Grenzen der Dampf- und Wasserräume, die zwischen den Absperreinrichtungen des Dampfkessels und des
Heißwassererzeugers in den Eintritts-, Austritts- Druckhalte-, Überström- und Ausblasleitungen liegen.
Anmerkung 1 zum Begriff: Die Gehäuse der Absperreinrichtungen und die sie mit dem Dampferzeuger verbindenden
Leitungen gehören zu den Wandungen.
3.3
Dampf- und Heißwassererzeugungsanlage
Anlage, bestehend aus einem oder mehreren Wasserrohrkesseln und seinen Ausrüstungsteilen, wie in
EN 12952-1 definiert
3.4
Beheizungssystem
Gesamtheit von Bauteilen, in denen die Energie des Brennstoffs (einschließlich elektrischer Energie und
Abhitze) zum Dampf- und Heißwassererzeuger geliefert wird
3.5
Einteilung der Druckhalte-Systeme (Heißwassererzeuger)
3.5.1
Anlage mit Eigendruckhaltung
Anlage, bei der Druck durch den der Vorlauftemperatur entsprechenden Sättigungsdruck erzeugt wird
3.5.2
Anlage mit Fremddruckhaltung
Anlage, bei der Druck durch bestimmte Systeme, wie z. B. Gaspolster oder Druckhaltepumpen, erzeugt wird
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3.6
Ausdehnungsgefäße
Behälter zur Aufnahme der auf die Temperatur bezogenen Änderungen im Wasservolumen
 geschlossene Ausdehnungsgefäße sind druckbeaufschlagt
 offene Ausdehnungsgefäße sind nicht druckbeaufschlagt, sondern bis zum atmosphärischen Druck
druckentlastet
3.7
maximale Dauerleistung (MCR)
höchster im Dauerbetrieb erzeugbarer Dampfmassenstrom
3.8
zulässige Wärmeleistung
höchste im Dauerbetrieb erzeugbare Wärmeleistung (Wassermassenstrom multipliziert mit der Differenz
zwischen Austritts- und Eintrittsenthalpie), mit der Heißwassererzeuger betrieben werden dürfen
3.9
höchster zulässiger Druck (PS)
vom Hersteller angegebener höchster Druck, für den das Druckgerät an einer vom Hersteller festgelegten
Stelle ausgelegt ist
Anmerkung 1 zum Begriff: Hierbei handelt es sich um die Anschlussstelle der Schutz- oder Begrenzungseinrichtungen
oder um den höchsten Punkt des Druckgeräts oder anderenfalls um jede sonstige angegebene Stelle.
3.10
höchste zulässige Temperatur (TS)
höchste Fluidtemperatur, für die die Ausrüstungsteile an einer vom Hersteller festgelegten Stelle konstruiert
sind
Anmerkung 1 zum Begriff: Üblicherweise befindet sich diese Stelle am Auslass des Kessels.
3.11
Regler
Einrichtungen, die eine Angleichung der zu regelnden Größe (z. B. Wasserstand, Druck, Temperatur) an
einen vorzugebenden Wert (Sollwert) bewirken
3.12
Begrenzer
Begrenzungseinrichtung die bei Erreichen eines fest eingestellten Werts (z. B. für Druck, Temperatur,
Durchfluss, Wasserstand) die Wärmezufuhr unterbricht und verriegelt und vor dem Wiedereinschalten
manuell entriegelt werden muss
Eine Begrenzungseinrichtung beinhaltet:
 eine Mess- oder Erkennungsfunktion; und
 eine Auslösefunktion für Korrekturen oder die Abschaltung oder die Abschaltung mit Verriegelung;
und wird entweder allein oder als Teil eines Schutzsystems (z. B. Sensoren, Begrenzer usw.) für in der
Druckgeräterichtlinie 97/23/EG (DGRL) [1] definierte sicherheitsrelevante Funktionen angewendet (siehe auch
Bild 1). Werden dazu Mehrkanalsysteme verwendet, müssen alle Komponenten oder Begrenzer für
sicherheitsrelevante Anwendungen in das Schutzsystem einbezogen sein.
Anmerkung 1 zum Begriff: Das manuelle Rücksetzen kann entweder als Teil des Begrenzers oder der Sicherheitslogik
realisiert werden. Den Vorgang der manuellen Rücksetzung führt der verantwortliche Kesselwärter unter Berücksichtigung
der physikalischen Situation durch.
Anmerkung 2 zum Begriff: Siehe Anhang D für Begrenzer, die auf analogen Messungen basieren.
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Bild 1 — Schutzeinrichtungen und Sicherheitszubehör gemäß der Richtlinie 97/23/EG (DGRL)
3.13
unabhängig
Fähigkeit, ohne Dazwischenschalten anderer Ausrüstungsteile auf die erforderliche Weise zu funktionieren
3.14
Zuverlässigkeit
Fähigkeit, eine bestimmungsgemäße Funktion unter vorgeschriebenen Bedingungen und über eine bestimmte
Zeitspanne ohne Versagen durchzuführen
3.15
Funktionsprüfung
Prüfung der Sicherheitseinrichtung, um sicherzustellen, dass die vorgesehene Funktion ausgeführt wird
3.16
Kesselwärter
Bedienungsperson für den Kessel
für die Bedienung der Kesselanlage eingesetzte, in geeigneter Weise qualifizierte Person
3.17
normale Abschaltung
kontrolliertes Ausschalten des Kessels, entweder manuell oder automatisch
3.18
Normalbetrieb
Betrieb, bei dem alle Steuerkreise und Regler (Schaltungen ohne/mit Rückführung) im Normalmodus bei den
für den normalen Betrieb zutreffenden Sollwerten und Parametern arbeiten. Bei Betrieb ohne manuellen
Eingriff befinden sich alle Steuerkreise und Regler (Schaltungen ohne/mit Rückführung) im automatischen
Modus
Anmerkung 1 zum Begriff: Zum Normalbetrieb gehören auch das automatische Einschalten und Ausschalten von
zugeordneten Betätigungsgliedern (z. B. Brenner).
3.19
Störabschaltung (Verriegelung)
Zustand nach einer durch das Schutzsystem veranlassten Sicherheitsabschaltung, bei dem ein Wiederein-
schalten nur durch den Kesselwärter durch manuelles Rücksetzen des Begrenzers oder der Sicherheitslogik
und auf keine andere Weise möglich ist
4 Allgemeine Anforderungen an Dampf- und Heißwassererzeuger
4.1 Sicherheitseinrichtungen gegen Überdruck
Jeder Dampferzeuger, Heißwassererzeuger und jeder absperrbare beheizte Raum muss in Übereinstimmung
mit EN 12952-10 mit Sicherheitseinrichtungen gegen Überdruck ausgerüstet sein.
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4.2 Beheizungssystem
4.2.1 Für die Beheizung von Dampf- und Heißwassererzeugern gelten die Anforderungen nach:
 EN 12952-8 für Feuerungsanlagen für flüssige und gasförmige Brennstoffe;
 EN 12952-9 oder EN 12952-16 für Feuerungsanlagen für feste Brennstoffe.
4.2.2 Die Beheizung muss an die zulässige Wärmeleistung und die vorgesehene Betriebsweise angepasst
sein.
Die Beheizung muss regelbar sein und in allen Betriebsphasen an Veränderungen des Wärmebedarfs
angepasst werden.
4.2.3 Bei einer normalen Abschaltung oder Verriegelung darf die verbleibende Restwärme im Feuerraum
und in den Rauchgaszügen keine unzulässige Wand- oder Fluidtemperatur im Dampf-/Heißwassererzeuger
verursachen (z. B. durch Verdampfen des Wassers).
Diese Anforderungen sind erfüllt, wenn:
 nachgewiesen wird, dass nach Unterbrechung der Beheizung aus Volllastbeharrung die Rauchgas-
temperatur in der Höhe des höchsten Feuerzugs (HF) 400 °C unterschreitet, bevor der Wasserstand von
der Marke des niedrigsten zulässigen Wasserstands (NW) auf 50 mm über dem höchsten Feuerzug (HF)
abgefallen ist; oder
 eine zuverlässige Speisewasserversorgung vorhanden ist, die bei einem plötzlichen Ausfall wichtiger
Betriebsparameter eine ausreichende Kühlung der Feuerzüge sicherstellt (siehe z. B. 5.1.1.2); oder
 Feuerungsanlagen für Öl, Gas oder pulverförmige Brennstoffe (ausgenommen Schmelzkammerfeuerung
oder ausgemauerte Feuerräume oder Rauchgaszüge) verwendet werden; oder
 es nur mit Gasen erwärmt wird, die eine Temperatur von 400 °C nicht überschreiten.
4.3 Entaschungsanlagen
Entaschungsanlagen müssen den Anforderungen in EN 12952-9 oder EN 12952-16 entsprechen.
4.4 Rauchgasreinigungsanlagen
Rauchgasreinigungsanlagen müssen den Anforderungen in EN 12952-13 und EN 12952-14 entsprechen.
4.5 Anforderungen an Begrenzungseinrichtungen und Schutzsysteme
4.5.1 Die Schutzsysteme müssen den Anforderungen in EN 50156-1 entsprechen.
Begrenzer und deren Anschlussleitungen müssen Anhang D oder EN 12952-11 entsprechen.
Die nach EN 50156-1 identifizierten Sicherheitsintegritätslevel (SIL) müssen umgesetzt werden.
4.5.2 Die Anwendungsplanung und Errichtung der elektrischen Sicherheitsschaltungen, die elektrische
Ausrüstung und die Regeleinrichtungen für Feuerungsanlagen und die zugehörigen Nebenanlagen müssen
EN 50156-1 entsprechen.
ANMERKUNG Falls erforderlich, sollte ein Abschalten des Kessels mit Hilfe von Zusatzeinrichtungen außerhalb des
Kessels möglich sein, z. B. durch Absperrarmaturen, Not-Ausschalteinrichtungen, Brandmelder usw.
4.5.3 Eine Funktionsprüfung der Begrenzer muss während des Betriebs jederzeit möglich sein.
Sofern geeignet, kann die Funktionsprüfung durch Simulation durchgeführt werden.
4.5.4 Wenn ein Begrenzer anspricht, muss eine Information übermittelt werden um anzuzeigen, welcher
Begrenzer aktiviert wurde.
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4.5.5 Wenn ein Begrenzer bei Abhitzekesseln oder –erzeugern anspricht, muss die Beheizung unter-
brochen und abgeschaltet werden oder das Abgas muss um den Dampfkessel oder Heißwassergenerator
herum geführt werden. Die Umführung muss vom Kesselwärter manuell zurückgesetzt werden.
ANMERKUNG Falls das Abgas nicht innerhalb einer bestimmten Zeitspanne vollständig umgelenkt wird, sollte die
Beheizung unterbrochen werden.
4.6 Speiseleitungen und Sicherung gegen Rückströmen des Speisewassers
4.6.1 In jeder zum Dampf- oder Heißwassererzeuger führenden Speiseleitung muss eine Sicherung gegen
Rückströmen und eine Absperreinrichtung eingebaut sein. Werden Absperreinrichtung und Sicherung gegen
Rückströmen nicht in unmittelbarer Verbindung zueinander eingebaut, so muss für das dazwischen liegende
Rohrleitungsstück die Möglichkeit einer Druckentlastung gegeben sein.
Ein Zwangdurchlauf-Kessel, bei dem bei Ausfall der Speisewasserzufuhr die Beheizung selbsttätig
abgeschaltet wird, benötigt keine Absperreinrichtung und keine Sicherung gegen Rückströmen, wenn die
Speisewasserpumpe eine Verdrängerpumpe ist, die sicherstellen kann, dass keine gefährlichen Rückströme
auftreten können.
4.6.2 Außer für Zwangdurchlauf-Kessel muss die Speiseleitung so an den Dampf- oder Heißwasser-
erzeuger angeschlossen werden, dass er sich bei undichter Rückstromsicherung nicht tiefer als über den
höchsten Punkt der Fallrohre entleeren kann.
4.6.3 Speisewasserpumpen müssen von gemeinschaftlichen Saug- oder Druckleitungen absperrbar sein.
4.6.4 Wenn in der Saugleitung des Speisewassers ein Absperrventil installiert ist, sollten das Absperrventil
und die Leitung zwischen dem Absperrventil und der Speisepumpe für die gleichen Bedingungen ausgelegt
sein wie die Druckleitung zum Kessel oder geeignete Einrichtungen müssen angebracht sein, die eine
Gefährdung durch Überdruck bei geschlossenem Absperrventil ausschließen.
4.7 Verbindung von Dampf- oder Heißwassererzeugern
Bleiben bei einer Dampf- oder Heißwassererzeugungsanlage mit mehreren durch gemeinsame Leitungen
verbundenen Dampf- oder Heißwassererzeugern beim Befahren der Dampf- oder Heißwassererzeuger die
Absperreinrichtungen in den Heißwasser- und Speiseleitungen mit diesen Leitungen unlösbar verbunden,
müssen zur Sicherung jeweils zwei Absperreinrichtungen mit einer dazwischen liegenden Entlüftungs-
einrichtung eingebaut werden. Diese Absperreinrichtungen müssen in der geschlossenen Stellung
verriegelbar und gegen unzulässige Betätigung abgesichert sein.
4.8 Wasserqualität
4.8.1 Allgemeines
Die Wasserqualität muss mindestens EN 12952-12 sowie den Betriebsanleitungen entsprechen.
4.8.2 Probenahme
Es muss zu jedem Zeitpunkt während des Betriebs mögli
...

ba

SLOVENSKI SIST EN 12952-7

STANDARD
december 2012













Vodocevni kotli in pomožne napeljave – 7. del: Zahteve za opremo kotla

Water-tube boilers and auxiliary installations – Part 7: Requirements for equipment
for the boiler

Wasserrohrkessel und Anlagenkomponenten – Teil 7: Anforderungen an die
Ausrüstung für den Kessel

Chaudières à tubes d'eau et installations auxiliaires – Partie 7: Exigences pour
l'équipement de la chaudière



















Referenčna oznaka
ICS 27.060.30 SIST EN 12952-7:2012 (sl)

 Nadaljevanje na straneh II do III in od 1 do 42

©
2020-10: Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni
dovoljeno.

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SIST EN 12952-7 : 2012

NACIONALNI UVOD

Standard SIST EN 12952-7:2012 (sl), Vodocevni kotli in pomožne napeljave – 7. del: Zahteve za opremo
kotla, 2012, ima status slovenskega standarda in je istoveten evropskemu standardu EN 12952-7 (en),
Water-tube boilers and auxiliary installations – Part 7: Requirements for equipment for the boiler, 2012.

Ta standard nadomešča SIST EN 12952-7:2002.

NACIONALNI PREDGOVOR

Evropski standard EN 12952-7:2012 je pripravil tehnični odbor Evropskega komiteja za standardizacijo
CEN/TC 269 "Mnogovodni in vodocevni kotli", katerega sekretariat vodi DIN.

Slovenski standard SIST EN 12952-7:2012 (sl) je prevod evropskega standarda EN 12952-7:2012. V
primeru spora glede besedila slovenskega prevoda v tem standardu je odločilen izvirni evropski
standard v angleškem jeziku. Slovensko izdajo standarda je pripravil tehnični odbor SIST/TC TLP
Tlačne posode.

Odločitev za privzem tega standarda je 25. oktobra 2012 sprejel tehnični odbor SIST/TC TLP Tlačne
posode.

ZVEZE S STANDARDI

S privzemom tega evropskega standarda veljajo za omejeni namen referenčnih standardov vsi
standardi, navedeni v izvirniku, razen tistih, ki so že sprejeti v nacionalno standardizacijo:

SIST EN 837-1 Merilniki tlaka – 1. del: Merilniki tlaka z Bourdonovo cevjo – Mere,
meroslovje, zahteve in preskušanje

SIST EN 12952-1:2002  Vodocevni kotli in pomožne napeljave – 1. del: Splošno

SIST EN 12952-3:2012  Vodocevni kotli in pomožne napeljave – 3. del: Konstruiranje in izračun
tlačno obremenjenih delov

SIST EN 12952-8:2002  Vodocevni kotli in pomožne napeljave – 8. del: Zahteve za gorilnike kotlov
na tekoča in plinasta goriva

SIST EN 12952-9:2003  Vodocevni kotli in pomožne napeljave – 9. del: Zahteve za gorilnike kotlov
na premogov prah

SIST EN 12952-10:2003 Vodocevni kotli in pomožne napeljave – 10. del: Zahteve za opremo in
varnostne naprave za preprečevanje prekoračitve tlaka

SIST EN 12952-11:2007  Vodocevni kotli in pomožne napeljave – 11. del: Zahteve za omejilne
naprave kotla in opremo

SIST EN 12952-12:2004 Vodocevni kotli in pomožne napeljave – 12. del: Zahteve za kakovost
napajalne in kotelne vode

SIST EN 12952-13  Vodocevni kotli in pomožne napeljave – 13. del: Zahteve za čistilne naprave
dimnih plinov

SIST EN 12952-14  Vodocevni kotli in pomožne napeljave – 14. del: Zahteve za naprave dimnih
plinov DENOX na tekoči amoniak in vodno raztopino amoniaka

SIST EN 12952-16:2003  Vodocevni kotli in pomožne napeljave – 16. del: Zahteve za kurilne sisteme
na trdna goriva z zgorevalno rešetko ali z lebdečo plastjo

SIST EN 12952-18  Vodocevni kotli in pomožne napeljave – 18. del: Navodila za obratovanje

SIST EN 50156-1:2006 Električna oprema za peči in pomožno opremo – 1. del: Zahteve za zasnovo
in inštalacijo naprave

II

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SIST EN 12952-7 : 2012

OSNOVA ZA IZDAJO STANDARDA

– privzem evropskega standarda EN 12952-7:2012

OPOMBE

– Povsod, kjer se v besedilu standarda uporablja izraz "evropski standard", v SIST EN 12952-7:2012
to pomeni "slovenski standard".

– Nacionalni uvod in nacionalni predgovor nista sestavni del standarda.

– Ta nacionalni dokument je istoveten EN 12952-7:2012 in je objavljen z dovoljenjem

 Upravni center
 CEN-CENELEC
 Avenue Marnix 17
 B-1000 Bruselj

This national document is identical with EN 12952-7:2012 and is published with the permission of

  CEN-CENELEC
  Management Centre
 Avenue Marnix 17
  B-1000 Brussels


III

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SIST EN 12952-7 : 2012


IV

---------------------- Page: 4 ----------------------
EVROPSKI STANDARD  EN 12952-7
EUROPEAN STANDARD

NORME EUROPÉENNE
 oktober 2012
EUROPÄISCHE NORM

ICS 27.040    Nadomešča EN 12952-7:2002






Slovenska izdaja

Vodocevni kotli in pomožne napeljave – 7. del: Zahteve za opremo kotla

Water-tube boilers and auxiliary Chaudières à tubes d'eau et Wasserrohrkessel und
installations – Part 7: installations auxiliaires – Anlagenkomponenten –
Requirements for equipment for Partie 7: Exigences pour Teil 7: Anforderungen an die
the boiler l'équipement de la chaudière Ausrüstung für den Kessel





Ta evropski standard je CEN sprejel 8. septembra 2012.

Člani CEN morajo izpolnjevati določila notranjih predpisov CEN/CENELEC, s katerimi je predpisano,
da mora biti ta evropski standard brez kakršnih koli sprememb sprejet kot nacionalni standard.
Seznami najnovejših izdaj teh nacionalnih standardov in njihovi bibliografski podatki so na voljo na
zahtevo pri Upravnem centru CEN-CENELEC ali članih CEN.

Ta evropski standard obstaja v treh uradnih izdajah (angleški, francoski in nemški). Izdaje v drugih
jezikih, ki jih člani CEN na lastno odgovornost prevedejo in izdajo ter prijavijo pri Upravnem centru
CEN-CENELEC, veljajo kot uradne izdaje.

Člani CEN so nacionalni organi za standarde Avstrije, Belgije, Bolgarije, Cipra, Češke republike,
Danske, Estonije, Finske, Francije, Grčije, Hrvaške, Irske, Islandije, Italije, Latvije, Litve,
Luksemburga, Madžarske, Malte, Nekdanje jugoslovanske republike Makedonije, Nemčije,
Nizozemske, Norveške, Poljske, Portugalske, Romunije, Slovaške, Slovenije, Španije, Švedske,
Švice, Turčije in Združenega kraljestva.












CEN
Evropski komite za standardizacijo
European committee for standardization
Comité européen de normalisation
Europäisches komitee für normung

Upravni center: Avenue Marnix 17, B-1000 Bruselj


© 2012 CEN Lastnice avtorskih pravic so vse države članice CEN.     Ref. oznaka EN 12952-7:2012 E

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SIST EN 12952-7 : 2012
VSEBINA Stran

Predgovor . 3
1 Področje uporabe . 5
2 Zveze s standardi . 5
3 Izrazi in definicije . 5
4 Splošne zahteve za parne in vročevodne kotle . 8
5 Posebne zahteve za parne kotle . 12
6 Posebne zahteve za vročevodne kotle . 15
7 Dodatne zahteve za postrojenja brez ročnega posega . 20
8 Končna kontrola vodocevnega kotlovskega postrojenja . 22
Dodatek A (normativni): Kotli na odpadno gorivo (kotli na črno lužino) . 23
Dodatek B (informativni): Vidiki obratovanja kotlov . 25
Dodatek C (informativni): Alarmi in nadzor kotlovskega postrojenja . 30
Dodatek D (normativni): Zahteve za omejilnike, ki temeljijo na analognih meritvah . 31
Dodatek E (normativni): Dostop do notranjih delov . 35
Dodatek F (normativni): Končna kontrola vodocevnega kotlovskega postrojenja . 38
Dodatek G (informativni): Drenažne in izlivne naprave . 39
Dodatek H (informativni): Pomembne tehnične spremembe med tem evropskim standardom in
predhodno izdajo . 40
Dodatek ZA (informativni): Povezava med tem evropskim standardom in bistvenimi
zahtevami Direktive EU 97/23/ES . 41
Literatura. 42

2

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SIST EN 12952-7 : 2012

Predgovor

Ta dokument (EN 12952-7:2012) je pripravil tehnični odbor CEN/TC 269 "Mnogovodni in vodocevni
kotli", katerega sekretariat vodi DIN.

Ta evropski standard mora dobiti status nacionalnega standarda bodisi z objavo istovetnega besedila
ali z razglasitvijo najpozneje aprila 2013, nasprotujoče nacionalne standarde pa je treba razveljaviti
najpozneje aprila 2013.

Opozoriti je treba na možnost, da so lahko nekateri elementi tega dokumenta predmet patentnih pravic.
CEN [in/ali CENELEC] ne prevzema odgovornosti za ugotavljanje posameznih ali vseh takih patentnih
pravic.

Ta dokument nadomešča standard EN 12952-7:2002.

Ta dokument je bil pripravljen na podlagi mandata, ki sta ga Evropska komisija in Evropsko združenje
za prosto trgovino podelila CEN, in podpira bistvene zahteve direktiv EU.

Za povezavo z Direktivo EU 97/23/ES glej informativni dodatek ZA, ki je sestavni del tega dokumenta.

V dodatku H so podrobno opisane pomembne tehnične spremembe med to in predhodno izdajo tega
evropskega standarda.

Skupino evropskih standardov EN 12952, ki obravnava vodocevne kotle in pomožne napeljave,
sestavljajo naslednji deli:

 1. del: Splošno

 2. del: Materiali za tlačno obremenjene dele in opremo kotla

 3. del: Konstruiranje in izračun tlačno obremenjenih delov kotla

 4. del: Izračun pričakovane življenjske dobe obratovanja

 5. del: Izdelava in izvedba tlačno obremenjenih delov kotla

 6. del: Kontrola med izdelavo, dokumentacija in označevanje tlačno obremenjenih delov kotla

 7. del: Zahteve za opremo kotla

 8. del: Zahteve za gorilnike kotlov na tekoča in plinasta goriva

 9. del: Zahteve za gorilnike kotlov na premogov prah

 10. del: Zahteve za opremo in varnostne naprave za preprečevanje prekoračitve tlaka

 11. del: Zahteve za omejilne naprave kotla in opremo

 12. del: Zahteve za kakovost napajalne in kotelne vode

 13. del: Zahteve za čistilne naprave dimnih plinov

 14. del: Zahteve za naprave dimnih plinov DENOX na tekoči amoniak in vodno raztopino amoniaka

 15. del: Prevzemni preskusi

 16. del: Zahteve za kurilne sisteme na trdna goriva z zgorevalno rešetko ali z lebdečo plastjo

 CR 12952 – 17. del: Smernica za vključevanje kontrolnega organa, neodvisnega od proizvajalca

 18. del: Navodila za obratovanje



3

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SIST EN 12952-7 : 2012
Čeprav je te dele mogoče pridobiti posamično, je treba upoštevati, da so deli medsebojno odvisni. Zato
je treba pri konstruiranju in proizvodnji vodocevnih kotlov uporabljati več delov, da so zahteve tega
evropskega standarda zadovoljivo izpolnjene.

OPOMBA 1: 4. in 15. del nista namenjena konstruiranju, izdelavi in vgradnji.

OPOMBA 2: CEN/TC 269 je vzpostavil "Službo za pomoč v zvezi s kotli", na katero se je mogoče obrniti v primeru kakršnih
koli vprašanj glede uporabe evropskih standardov skupine EN 12952 in EN 12953; glej naslednjo spletno stran:
http://www.boiler-helpdesk.din.de

V skladu z notranjimi predpisi CEN/CENELEC morajo ta evropski standard obvezno uvesti nacionalne
organizacije za standardizacijo naslednjih držav: Avstrije, Belgije, Bolgarije, Cipra, Češke republike,
Danske, Estonije, Finske, Francije, Grčije, Hrvaške, Irske, Islandije, Italije, Latvije, Litve, Luksemburga,
Madžarske, Malte, Nekdanje jugoslovanske republike Makedonije, Nemčije, Nizozemske, Norveške,
Poljske, Portugalske, Romunije, Slovaške, Slovenije, Španije, Švedske, Švice, Turčije in Združenega
kraljestva.


4

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SIST EN 12952-7 : 2012

1 Področje uporabe

Ta del evropskega standarda določa bistvene zahteve za opremo in zaščitne naprave za vodocevne
kotle, kot je določeno v standardu EN 12952-1, kar zagotavlja varno delovanje kotla v dovoljenih mejah
(tlak, temperatura itd.).

OPOMBA 1: Dodatne zahteve, ki jih je treba posebej upoštevati za kotle brez ročnega posega, so podane v točki 7.

OPOMBA 2: Zahteve za opremo kotlov na odpadno gorivo so navedene v dodatku A.

2 Zveze s standardi

Ta dokument se v celoti ali delno normativno sklicuje na naslednje dokumente, ki so nepogrešljivi pri
njegovi uporabi. Pri datiranih sklicevanjih se uporablja samo navedena izdaja. Pri nedatiranih
sklicevanjih se uporablja zadnja izdaja referenčnega dokumenta (vključno z vsemi dopolnili).

EN 837-1 Merilniki tlaka – 1. del: Merilniki tlaka z Bourdonovo cevjo – Mere, meroslovje,
zahteve in preskušanje

EN 12952-1:2001 Vodocevni kotli in pomožne napeljave – 1. del: Splošno

EN 12952-3:2011 Vodocevni kotli in pomožne napeljave – 3. del: Konstruiranje in izračun tlačno
obremenjenih delov

EN 12952-8:2002 Vodocevni kotli in pomožne napeljave – 8. del: Zahteve za gorilnike kotlov na
tekoča in plinasta goriva

EN 12952-9:2002 Vodocevni kotli in pomožne napeljave – 9. del: Zahteve za gorilnike kotlov na
premogov prah

EN 12952-10:2002 Vodocevni kotli in pomožne napeljave – 10. del: Zahteve za opremo in
varnostne naprave za preprečevanje prekoračitve tlaka

EN 12952-11:2007 Vodocevni kotli in pomožne napeljave – 11. del: Zahteve za omejilne naprave
kotla in opremo

EN 12952-12:2003 Vodocevni kotli in pomožne napeljave – 12. del: Zahteve za kakovost
napajalne in kotelne vode

EN 12952-13 Vodocevni kotli in pomožne napeljave – 13. del: Zahteve za čistilne naprave
dimnih plinov

EN 12952-14 Vodocevni kotli in pomožne napeljave – 14. del: Zahteve za naprave dimnih
plinov DENOX na tekoči amoniak in vodno raztopino amoniaka

EN 12952-16:2002 Vodocevni kotli in pomožne napeljave – 16. del: Zahteve za kurilne sisteme
na trdna goriva z zgorevalno rešetko ali z lebdečo plastjo

EN 12952-18 Vodocevni kotli in pomožne napeljave – 18. del: Navodila za obratovanje

EN 50156-1:2004 Električna oprema za peči in pomožno opremo – 1. del: Zahteve za zasnovo
in inštalacijo naprave

3 Izrazi in definicije

V tem dokumentu se uporabljajo izrazi in definicije, navedeni v standardih EN 12952-1:2001, EN 12952-
8:2002, EN 12952-9:2002, EN 12952-11:2007, EN 12952-12:2003 in EN 12952-16:2002, ter naslednji
izrazi in definicije.





5

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SIST EN 12952-7 : 2012
3.1
vrste parnih in vročevodnih kotlov

3.1.1
kotli z naravno cirkulacijo (kroženjem)
parni in vročevodni kotli, v katerih voda za uparjanje oziroma ogrevanje cirkulira (kroži) zaradi razlik v
gostoti

3.1.2
kotli s prisilno cirkulacijo (kroženjem)
parni in vročevodni kotli, v katerih voda za uparjanje oziroma ogrevanje cirkulira (kroži) s pomočjo črpalk

3.1.3
pretočni parni in vročevodni kotli
parni kotli s parno posodo ali brez nje, pri katerih se pretok vode določa z napajalno črpalko in v katerih
se voda v celoti ali večinoma upari pri enkratnem pretoku skozi kotel

Opomba 1: Vročevodni kotli, pri katerih pretok vode poteka s pomočjo obtočne (cirkulacijske) črpalke ogrevalnega sistema in
v katerih se voda ogreje pri enkratnem pretoku skozi kotel, npr. pretočni vročevodni kotli, kjer ni mešanja hladne
in vroče vode v bobnu kotla (dvosmerni boben), ali pretočni vročevodni kotli s spodnjim razdelilnikom vode.

3.1.4
parni in vročevodni kotli, ogrevani z odpadno toploto
kotli, ki se ogrevajo s toploto iz zunanjega vira, npr. iz plinske turbine, visoke peči

3.2
priključne meje parnih in vročevodnih kotlov
razmejitve parnih in vodnih prostorov parnih in vročevodnih kotlov, ki so razporejeni med zapornimi
napravami na vstopnem in izstopnem vodu, vodu za tlačno razbremenitev, prelivnem vodu in drenažnih
vodih

Opomba 1: Šteje se, da so ohišja zapornih naprav znotraj teh mej.

3.3
parno in vročevodno kotlovsko postrojenje
postrojenje sestavljajo eden ali več vodocevnih kotlov ter pripadajoče naprave in oprema, kot je
opredeljeno v EN 12952-1

3.4
generator toplote
sestav elementov, ki parni ali vročevodni kotel oskrbujejo z energijo goriva (vključno z električno energijo
in odpadno toploto)

3.5
razvrstitev sistemov za vzdrževanje tlaka (vročevodni kotli)

3.5.1
naprave z lastnim vzdrževanjem tlaka
sistem, v katerem se tlak ustvari s tlakom nasičenja, ki ustreza temperaturi dovoda

3.5.2
naprave z zunanjim vzdrževanjem tlaka
naprave, pri katerih se tlak vzdržuje s pomočjo zunanjih sistemov, kot npr. plinska blazina ali črpalke za
vzdrževanje tlaka

3.6
raztezne posode
posode, ki kompenzirajo raztezek vode zaradi temperaturnih sprememb:

6

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SIST EN 12952-7 : 2012

 zaprte raztezne posode pod tlakom

 proti zunanji atmosferi odprte raztezne posode, ki niso pod tlakom

3.7
največja trajna zmogljivost (MCR)
največja masna količina pare pri stalnem obratovanju kotla

3.8
dovoljena toplotna moč
največja toplotna moč (pretok vode, pomnožen z razliko med izhodno in vhodno entalpijo), ki se lahko
doseže med stalnim obratovanjem in s katero sme vročevodni kotel obratovati

3.9
najvišji dovoljeni tlak (PS)
najvišji tlak, za katerega je naprava načrtovana in ga je podal proizvajalec, merjen na mestu, ki ga je
določil proizvajalec

Opomba 1: To je lahko mesto priključitve zaščitnih in/ali omejilnih naprav ali najvišje mesto na napravi ali, če to ni primerno,
katerokoli drugo določeno mesto.

3.10
najvišja dovoljena temperatura (TS)
najvišja temperatura fluida, za katero je proizvajalec načrtoval opremo, merjena na mestu, ki ga je določil
proizvajalec

Opomba 1: Ponavadi je to na odvodu iz kotla.

3.11
regulacijska oprema
regulator
naprave, ki uravnavajo spremenljive vrednosti (npr. nivo vode, tlak, temperaturo) v mejah nastavljenih
vrednosti

3.12
omejilnik
omejilna naprava, ki v primeru, ko je dosežena nastavljena vrednost (npr. tlaka, temperature, pretoka,
nivoja vode), prekine in izklopi dovod toplote in mora biti pred ponovnim zagonom naprave ročno
odblokirana

Omejilna naprava mora imeti:

 merilno ali zaznavalno funkcijo in

 sprožilno funkcijo (aktiviranje) za popravke ali zaustavitev ali varnostno zaustavitev in zaklepanje

in se uporablja samostojno ali kot del zaščitnega sistema (npr. tipala, omejilniki) za izvajanje varnostnih
funkcij, določenih v Direktivi 97/23/ES o tlačni opremi (PED) (glej tudi sliko 1). Če je ta funkcija izvedena
z večkanalnimi sistemi, so vsi varnostni elementi ali omejilniki vključeni v zaščitni sistem.

Opomba 1: Ročno ponastavitev je mogoče izvesti na omejilniku ali s pomočjo varnostne logike. To ob upoštevanju
dejanskega stanja izvede odgovorni upravljavec.

Opomba 2: Za omejilnike, ki temeljijo na analognih meritvah, glej dodatek D.







7

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Zaščitna naprava




Varnostna armatura Nadzorna naprava




Omejilnik (omejilna naprava)
…. Varnostni ventil Razpočni disk

tipalo→varnostna logika→pogonska enota (aktuator)


Slika 1: Zaščitne naprave in varnostne armature v skladu z Direktivo 97/23/ES (PED)

3.13
neodvisnost
sposobnost zahtevanega delovanja brez vpliva druge opreme

3.14
zanesljivost
sposobnost opravljanja zahtevane funkcije pod določenimi pogoji in v določenem času brez odpovedi
delovanja

3.15
funkcionalni preskus
preskušanje varnostne opreme za zagotovitev, da oprema opravlja predvideno funkcijo

3.16
upravljavec kotla ali kotlovskih naprav
usposobljena oseba, ki upravlja kotlovsko postrojenje

3.17
normalna zaustavitev
nadzorovana zaustavitev kotla, vodena ročno ali avtomatsko

3.18
normalno obratovanje
obratovanje z delovanjem vseh regulacijskih krogov in krmilnikov (odprti/zaprti krogi) v mejah
nastavljenih vrednosti parametrov za normalno obratovanje. Pri obratovanju brez ročnega posega vsi
regulacijski krogi in krmilniki (odprti/zaprti krogi) delujejo samodejno (avtomatsko).

Opomba 1: Normalno obratovanje vključuje tudi avtomatski vklop in izklop pripadajočih pogonov (npr. gorilnika).

3.19
varnostna zaustavitev
stanje po zaustavitvi, ki jo je aktiviral zaščitni sistem, pri katerem lahko ponovni zagon naprave doseže
le upravljavec kotla z ročnim odblokiranjem omejilnika ali z ročnim odblokiranjem varnostne logike
naprave in ne na drug način

4 Splošne zahteve za parne in vročevodne kotle

4.1 Oprema in varnostne naprave za preprečevanje prekoračitve tlaka

Vsak parni ali vročevodni kotel ter vsak ogrevan predel, ki ga je mogoče izolirati, je treba opremiti z
opremo in varnostnimi napravami za preprečevanje prekoračitve tlaka v skladu s standardom EN 12952-
10.


8

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4.2 Generator toplote

4.2.1 Zahteve za dovod toplote za parne in vročevodne kotle morajo biti v skladu s standardi:

 EN 12952-8 za kurilne naprave na tekoča in plinasta goriva;

 EN 12952-9 ali EN 12952-16 za kurilne naprave na trdna goriva.

4.2.2 Dovod toplote je treba prilagoditi dovoljeni toplotni moči in predvidenemu načinu obratovanja.

Dovod toplote je treba nadzorovati in ga prilagoditi spreminjanju potrebe po toploti v vseh fazah
obratovanja.

4.2.3 V primeru normalne ali varnostne zaustavitve preostala toplota v kurišču in odvodnikih dimnih
plinov ne sme povzročiti nesprejemljivih temperatur kovine ali fluida (npr. z uparjanjem vode) v
parnem/vročevodnem kotlu.

Ta zahteva je izpolnjena:

 če je dokazano, da po prekinitvi dovoda toplote pri ustaljenih pogojih polne obremenitve
temperatura dimnih plinov na najvišji točki grelne površine (HHS) pade pod 400 °C, preden nivo
vode pade z najnižjega dovoljenega nivoja vode (LWL) na 50 mm nad najvišjo točko grelne
površine (HHS); ali

 če je vgrajen zanesljiv dovod napajalne vode, ki zagotavlja ustrezno hlajenje grelnih površin v
primeru nenadne izgube bistvenih obratovalnih parametrov (glej npr. točko 5.1.1.2); ali

 s kurilnimi napravami na olje, plin ali prah (razen pri kurjenju žlindre ali opečnatem kurišču ali
odvodnikih dimnih plinov); ali

 če se ogreva samo s plini s temperaturo, nižjo od 400 °C.

4.3 Naprave za odstranjevanje pepela

Naprave za odstranjevanje pepela morajo biti v skladu s standardoma EN 12952-9 ali EN 12952-16.

4.4 Čistilne naprave dimnih plinov

Čistilne naprave dimnih plinov morajo biti v skladu s standardoma EN 12952-13 ali EN 12952-14.

4.5 Zahteve za omejilne in zaščitne naprave

4.5.1 Zaščitne naprave morajo biti v skladu s standardom EN 50156-1.

Omejilniki in njihova vgradnja morajo biti v skladu z dodatkom D ali standardom EN 12952-11.

Uvesti je treba ustrezne ravni celovite varnosti (SIL), opredeljene v skladu s standardom EN 50156-1.

4.5.2 Zasnova in vgradnja električnega varnostnega tokokroga ter električne in regulacijske opreme za
dovod toplote ter njegove pomožne opreme morata biti v skladu s standardom EN 50156-1.

OPOMBA: Če je zahtevano, naj bo omogočena zaustavitev kotla z dodatnimi napravami zunaj kotla, kot so zaporni ventil,
naprava za izklapljanje v sili, javljalniki požara itd.

4.5.3 Kadar koli med obratovanjem mora biti mogoče funkcionalno preskusiti vse omejilnike.

Kjer je ustrezno, se lahko funkcionalni preskus izvede s simulacijo.

4.5.4 Ko se omejilnik aktivira, mora upravljavec dobiti podatek, kateri omejilnik se je aktiviral.

9

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4.5.5 Ko se pri kotlih, ogrevanih z odpadno toploto, aktivira omejilnik, je treba dovod toplote prekiniti in
varnostno zaustaviti ali preusmeriti pretok odpadnega plina, da obide parni ali vročevodni kotel.
Upravljavec kotla mora obvod ročno ponastaviti.

OPOMBA: Če se v času, ki je določen, pretok odpadnega plina ne preusmeri v celoti na obvod, naj se dovod toplote prekine.

4.6 Napajalni vodi in zaščita pred povratnim tokom napajalne vode

4.6.1 Vsak napajalni vod, ki vodi v parni ali vročevodni kotel, je treba opremiti z napravo za zaščito pred
povratnim tokom in zaporno napravo. Če zaporna naprava in naprava za zaščito pred povratnim tokom
nista nameščeni tako, da sta med seboj neposredno povezani, mora biti za vmesni del cevi omogočena
razbremenitev tlaka.

Pri pretočnem parnem kotlu, pri katerem se dovod toplote v primeru napake pri dovodu napajalne vode
prekine avtomatsko, zaporna naprava ali naprava za zaščito pred povratnim tokom ni potrebna, če je
vgrajena črpalka s pozitivnim premikom, ki zagotavlja, da ne pride do nevarnega povratnega toka.

4.6.2 Razen pri pretočnih kotlih je napajalni vod treba priključiti na parni ali vročevodni kotel tako, da se
v primeru puščanja naprave za zaščito pred povratnim tokom parni kotel ne more izprazniti pod najvišjo
točko padnih cevi.

4.6.3 Napajalne črpalke morajo imeti možnost izolacije pred skupnimi sesalnimi ali tlačnimi vodi.

4.6.4 Če je v sesalni vod napajalne vode vgrajen izolacijski ventil, naj bosta izolacijski ventil in vod med
izolacijskim ventilom in napajalno črpalko konstruirana za enake pogoje kot tlačni vod do kotla, sicer je
treba vgraditi ustrezne naprave, da se prepreči nevarnost nadtlaka, če je izolacijski ventil zaprt.

4.7 Povezava parnih ali vročevodnih kotlov

Če je v parnem ali vročevodnem kotlovskem postrojenju več parnih ali vročevodnih kotlov, ki so
povezani s skupnimi vodi in so zaporne naprave v parnih ali vročevodnih kotlih ali napajalnih vodih trajno
povezane s temi vodi med kontrolo parnih ali vročevodnih kotlov, je treba v vsak vod vgraditi dve zaporni
napravi z vmesnim odzračevanjem. Zaporni napravi morata imeti možnost zaklepa v zaprtem položaju
in biti zaščiteni pred nenamernim aktiviranjem.

4.8 Kakovost vode

4.8.1 Splošno

Kakovost vode mora biti v skladu vsaj s standardom EN 12952-12 in navodili za obratovanje.

4.8.2 Vzorčenje

Kadar koli med obratovanjem mora biti omogočen varen odvzem zanesljivih vzorcev kotelne vode,
napajalne vode, dodajne vode in, če je potrebno, kondenzata in/ali povratne vode.

Glede na temperaturo medija je treba vzorce odvzeti s pomočjo enega ali več hladilnikov za vzorce.

4.8.3 Oprema za nadzor kakovosti vode v parnem kotlu

Vgraditi je treba opremo za nadzor prevodnosti vode v parnem kotlu.

Če visoka prevodnost lahko ogrozi varnost kotla ali obratovanje kateregakoli omejilnika, mora biti nadzor
stalen.

Če je prevodnost zunaj meja, navedenih v navodilih za obratovanje ali določenih v standardu EN 12952-
12, je treba izvesti ustrezne korektivne ukrepe.

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4.8.4 Kondenzat in dodajna voda v parnih kotlovskih postrojenjih

Oceniti je treba tveganje, ali bi lahko škodljive snovi (npr. olje, mast, organske snovi, kislina, lug, morska
voda, trdila, smola za ionsko izmenjavo itd.) prišle v sistem napajalne vode in/ali v kotel, kar bi ogrozilo
varnost kotla ali obratovanje omejilnikov.

Če se oceni, da tveganje obstaja, je treba vgraditi ustrezno nadzorno napravo, ki lahko zazna škodljivo
snov.

Če je zaznana škodljiva snov, ki bi lahko ogrozila varnost kotla ali obratovanje omejilnikov, je treba
izvesti ustrezne korektivne ukrepe.

OPOMBA: Če je vmesni tokokrog dvojnega obtočnega sistema napolnjen z mehčano vodo, se ne šteje, da obstaja nevarnost,
da bi lahko škodljiva snov prišla v sistem.

4.8.5 Sistem za kroženje vode v vročevodnih kotlovskih postrojenjih

Oceniti je treba tveganje, ali bi lahko škodljive snovi (npr. olje, mast, organske snovi, kislina, lug, morska
voda, trdila, smola za ionsko izmenjavo itd.) prišle v obtok, kar bi ogrozilo varnost kotla ali obratovanje
omejilnikov.

Če se oceni, da tveganje obstaja, je treba vgraditi ustrezno nadzorno napravo, ki lahko zazna škodljivo
snov.

Če je zaznana škodljiva snov, ki bi lahko ogrozila varnost kotla ali obratovanje omejilnikov, je treba
izvesti ustrezne korektivne ukrepe.

OPOMBA: Če je vmesni tokokrog dvojnega obtočnega sistema napolnjen z mehčano vodo, se ne šteje, da obstaja nevarnost,
da bi lahko škodljiva snov prišla v sistem.

4.9 Dostop do notranjih delov

Dostop do notranjih delov za opravila, kot so čiščenje, kontrola in vzdrževanje, mora biti v skladu z
dodatkom E.

4.10 Označevanje

Vsako vodocevno kotlo
...

SLOVENSKI STANDARD
oSIST prEN 12952-7:2010
01-julij-2010
Vodocevni kotli in pomožne napeljave - 7. del: Zahteve za opremo kotla
Water-tube boilers and auxiliary installations - Part 7: Requirements for equipment for the
boiler
Wasserrohrkessel und Anlagenkomponenten - Teil 7: Anforderungen an die Ausrüstung
für den Kessel
Chaudières à tubes d'eau et installations auxiliaires - Partie 7: Exigences pour
l'équipement de la chaudière
Ta slovenski standard je istoveten z: prEN 12952-7 rev
ICS:
27.060.30 Grelniki vode in prenosniki Boilers and heat exchangers
toplote
oSIST prEN 12952-7:2010 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 12952-7:2010

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oSIST prEN 12952-7:2010


EUROPEAN STANDARD
DRAFT
prEN 12952-7 rev
NORME EUROPÉENNE

EUROPÄISCHE NORM

May 2010
ICS 27.040 Will supersede EN 12952-7:2002
English Version
Water-tube boilers and auxiliary installations - Part 7:
Requirements for equipment for the boiler
Chaudières à tubes d'eau et installations auxiliaires - Partie Wasserrohrkessel und Anlagenkomponenten - Teil 7:
7: Exigences pour l'équipement de la chaudière Anforderungen an die Ausrüstung für den Kessel
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 269.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the
same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12952-7 rev:2010: E
worldwide for CEN national Members.

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oSIST prEN 12952-7:2010
prEN 12952-7:2010 (E)
Contents
Foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 General requirements for steam boilers and hot water generators . 8
5 Special requirements for steam boilers . 11
6 Special requirements for hot water generators . 14
7 Additional requirements for plants without manual intervention . 19
8 Final inspection . 23
Annex A (normative) Chemical recovery boilers (Black liquor recovery boilers) . 24
Annex B (informative) Design examples for hot water generating systems . 26
Annex C (informative) Aspects of boiler operation . 45
Annex D (informative) . 49
Annex E (normative) Requirements for limiters based on analogue transmitters and a Programmable
Safety Device (PSD) . 50
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 97/23/EC . 55
Bibliography . 56


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Foreword
This document (prEN 12952-7:2010) has been prepared by Technical Committee CEN/TC 269 “Shell and water-
tube boilers”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 12952-7:2002.
This document has been prepared under a mandate given to CEN by the European Commission and the European
Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.
The European Standard EN 12952 concerning water-tube boilers and auxiliary installations consists of the following
parts:
Part 1: General.
Part 2: Materials for pressure parts of boilers and accessories.
Part 3: Design and calculation for pressure parts.
Part 4: In-service boiler life expectancy calculations.
Part 5: Workmanship and construction of pressure parts of the boiler.
Part 6: Inspection during construction; documentation and marking of pressure parts of the boiler.
Part 7: Requirements for equipment for the boiler.
Part 8: Requirements for firing systems for liquid and gaseous fuels for the boiler.
Part 9: Requirements for firing systems for pulverized solid fuels for the boiler.
Part 10: Requirements for safeguards against excessive pressure.
Part 11: Requirements for limiting devices of the boiler and accessories.
Part 12: Requirements for boiler feedwater and boiler water quality.
Part 13: Requirements for flue gas cleaning systems.
Part 14: Requirements for flue gas DENOX-systems using liquified pressurized ammonia and ammonia water solu-
tion.
Part 15: Acceptance tests.
Part 16: Requirements for grate and fluidized bed firing systems for solid fuels for the boiler.
CR 12952-17: Guideline for the involvement of an inspection body independent of the manufacturer.
Although these parts can be obtained separately, it should be recognized that the parts are inter-dependent. As
such, the design and manufacture of water-tube boilers requires the application of more than one Part in order for
the requirements of the standard to be satisfactorily fulfilled.
NOTE Parts 4 and 15 are not applicable during the design, construction and installation stages.
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1 Scope
This Part of this European Standard specifies the minimum requirements for suitable protective devices for water-
tube boilers as defined in EN 12952-1, to ensure the boiler operates safely within the allowable limits (pressure,
temperature, etc.).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references,
only the edition cited applies. For undated references, the latest edition of the referenced document (including any
amendments) applies.
EN 837-1:1996, Pressure gauges — Part 1: Bourdon tube pressure gauges — Dimensions, metrology, require-
ments and testing.
EN 12952-1:2001, Water-tube boilers and auxiliary installations ― Part 1: General.
prEN 12952-6:2008, Water-tube boilers and auxiliary installations ― Part 6: Inspection during construction; docu-
mentation and marking of pressure parts of the boiler.
EN 12952-8:2002, Water-tube boilers and auxiliary installations ― Part 8: Requirements for firing systems for liquid
and gaseous fuels for the boiler.
EN 12952-9:2002, Water-tube boilers and auxiliary installations ― Part 9: Requirements for firing systems for pul-
verized solid fuels for the boiler.
EN 12952-10:2002, Water-tube boilers and auxiliary installations ― Part 10: Requirements for safeguards against
excessive pressure.
EN 12952-11:2007, Water-tube boilers and auxiliary installations ― Part 11: Requirements for limiting devices of
the boiler and accessories.
EN 12952-12:2003, Water-tube boilers and auxiliary installations ― Part 12: Requirements for feedwater and boiler
water quality.
EN 12952-13:2003, Water-tube boilers and auxiliary installations ― Part 13: Requirements for flue gas cleaning
systems.
EN 12952-14:2004, Water-tube boilers and auxiliary installations ― Part 14: Requirements for flue gas DE-
NOX-systems.
EN 12952-16:2002, Water-tube boilers and auxiliary installations ― Part 16:Requirements for fluidized bed and
grate firing systems for solid fuels for the boiler.
EN 50156-1:2004, Electrical equipment for furnaces and ancillary equipment — Part 1: Requirements for applica-
tion design and installation.
4

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3 Terms and definitions
For the purposes of this Part of this European Standard, the following terms and definitions apply in addition to
those given in EN 12952-1, EN 12952-8, EN 12952-9 and EN 12952-11.
3.1
Types of steam boilers and hot water generators
3.1.1
natural circulation steam boilers and hot water generators
steam boilers and hot water generators in which the water to be evaporated/heated circulates due to the differ-
ences in density (see Figure B.3-1)
3.1.2
forced or assisted circulation steam boilers and hot water generators
steam boilers and hot water generators in which the water to be evaporated/heated is circulated by means of
pumps (see Figure B.3-2)
3.1.3
once-through steam boilers and hot water generators
steam boilers, with or without separating vessels, where the water flow is determined by the feed pump, and the
water is evaporated completely or in a major portion during one single passage
Hot water generators, where the water flow is effected by the circulating pump of the heating system and is heated
during one single passage, e.g. once-through hot water generator where there is no contact between hot and cold
water in the drum (two-way drum) see Figure B.3-3 once-through hot water generator with header distributing water
from below, see Figures B.3-4 and B.4-9
3.1.4
waste heat steam boilers and hot water generators
generators utilizing heat recovered from outside sources, e.g. gas turbines, blast furnaces
3.2
limits of steam boilers and hot water generators
boundaries of the steam and water spaces located between the shut-off devices of the steam boilers and hot water
generators in the inlet, outlet, pressure retaining, overflow, and drain lines. The bodies of the shut-off devices are
considered to be within these limits
3.3
steam boilers and hot water generating plant
plant consists of the water-tube boiler and its equipment as defined in EN 12952-1
3.4
heat supply system
assembly of components in which the energy of the fuel (including electrical and waste-heat energy) is supplied to
the steam boilers and hot water generator
3.5
Classification of pressure generation systems (Hot water generators)

3.5.1
internally pressurised systems
systems where the pressure is generated by the saturation pressure corresponding to the flow temperature (see
Figures B.3-1, B.3-2, B.3-3, B.3-4, and Figure B.4-9)
3.5.2
externally pressurised systems
systems where the pressure is generated by such methods as gas cushion or pressure pumps (see Figures B.4-1
to B.4-8, B.4-10 to B.4-13)
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3.6
expansion vessels
containers to compensate for temperature related changes in volume dependent
 closed expansion vessels are pressurised
 open expansion vessels are vented to atmospheric pressure and are not pressurised
3.7
sinking time
time during which the water level will sink from the lowest permissible water level (LWL) to the highest point of the
heated surface (HHS) (see 4.5.2)
NOTE For hot water generators applicable only in the case of internal pressure generation; see Figures B.3-1, B.3-2,
B.3-3, B.3-4, and B.3-9.
3.8
maximum continuous rating (MCR)
maximum continuous steam output that can be generated during continuous operation taking the specified steam
condition into consideration
3.9
allowable heat output
maximum heat output (water mass flow times the difference between outlet and inlet enthalpy) that can be gener-
ated during continuous operation and at which hot water generators may be operated
3.10
maximum allowable pressure
maximum pressure for which equipment is designed, as specified by the manufacturer, and at a location specified
by the manufacturer
NOTE This may be the location of connection of protective and/or limiting devices or the top of equipment or, if not appli-
cable, any point specified.
3.11
allowable flow temperature
maximum allowable temperature at which the hot water generator may be operated
3.12
controls
devices used for holding the variable to be controlled (e.g. water level, pressure, temperature) at a specified value
(set point)
3.13
limiter
limiting device that, on reaching a fixed value (e.g. pressure, temperature, flow, water level) is used to interrupt and
lock-out the energy supply and requires manual unlocking before restart
limiting device requires:
 a measuring or detection function, and
 an activation function for correction, or shutdown, or shutdown and lockout,
and which is used to carry out safety related functions as defined in the PED 97/23/EC, either on its own or as part
of a protective system (e.g. sensors, limiters, etc.) (see also Figure 3.13). If this is achieved by multi channel sys-
tems, then all items or limiters for safety purposes are included within the protective system.
NOTE Manual resetting can be realised as a part of the limiter or as a part of the safety logic. This will be achieved by the
responsible operator taking into account of the physical situation.
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Figure 3.13 — Protective devices and safety accessories according to Directive PED 97/23/EC
3.14
independent
ability to function as required without interference from other equipment
3.15
reliability
ability to perform a required function under specified conditions and for a given period of time without failing
3.16
Functional check
testing of the safety device to ensure it performs its intended function
3.17
boiler attendant
boiler operator
skilled person appointed for operating the boiler plant
3.18
normal shut down
controlled switch off of the boiler either operated manually or automatically
3.19
normal operation
automatic operation, with all regulating circuits and controls (open loops/closed loops) in automatic mode and with
the set points and parameters valid for normal operation
NOTE Normal operation also includes the automatic switching on and off of the assigned actuators (e.g. burner).
3.20
lock-out
safety shut-down condition of the protective system, such that a restart can only be accomplished by a manual re-
set of the limiter or by a manual reset of the safety logic and by no other means
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4 General requirements for steam boilers and hot water generators
4.1 Hazard consideration
All service conditions shall be considered to select the most appropriate safety concept to ensure safe operation.

This requires an identification of the hazards by means of a hazard analysis in accordance with EN 50156-1.

Hazard analysis involves:

 Determination of the boundaries of the pressure equipment including intended use and reasonably fore-
seeable misuse;
 Identification of potential hazards.

On the basis of the hazard analysis, a judgement shall be made on how to achieve a high degree of health and
safety protection on the basis of:

 elimination or reduction of the hazards where this is possible,
 applying appropriate measures to protect the boiler against exceeding the allowable limits, where it is not
possible to eliminate or reduce the hazards, and/or
 give information about all residual hazards and details of the appropriate measures that shall be taken at
the time of installation and/or use.

4.2 Safeguards against excessive pressure
Each steam boiler, hot water generator and each isolatable heated compartment shall be equipped with safeguards
against excessive pressure in accordance with EN 12952-10 and the hazard analysis.
4.3 Heat supply system
4.3.1 The requirements for heat supply to steam boilers and hot water generators shall be in accordance with:
 EN 12952-8 for firing systems for liquid and gaseous fuels;
 EN 12952-9 or EN 12952-16 for solid fuels.
4.3.2 The heat supply shall be adapted to the allowable heat output as well as to the intended mode of operation.
The heat supply shall be controlled and in all operating stages adapted to the variation of the heat demand.

4.3.3 In the event of normal shutdown or lock out, residual heat accumulated in the furnace and flue-gas passes
shall not cause unacceptable metal temperatures (e.g. by evaporation of the water) in the steam boiler/hot water
generator.
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This requirement is deemed to be fulfilled e.g.

 if it is proved that, after interruption of the heat supply from the full load steady state condition, the flue-gas
o
temperature at the highest point of the heating surface (HHS) falls to below 400 C before the water level has
sunk from the lowest permissible water level (LWL) to 50 mm above the highest point of the heating surface
(HHS); or
 if a reliable feedwater supply is installed to ensure adequate cooling of the heating surfaces in case of a sud-
den loss of essential operational parameters (see e.g. 5.1.1.2); or
 in case of oil-, gas- or pulverized fuel firing systems (except slag-tap firing).
4.4 Ash removal plants
Ash removal plant shall be in accordance with EN 12952-9 or EN 12952-16.
4.5 Flue-gas cleaning plants
Flue-gas cleaning plants shall be in accordance with EN 12952-13 and EN 12952-14.
4.6 Requirements for limiting devices and safety circuits
4.6.1 The protective systems shall be in accordance with EN 50156-1.
Binary limiters and their installation shall be in accordance with EN 12952-11.
Limiters with analogue transmitters shall be in accordance with EN 50156-1 and Annex E.
4.6.2 The application design and installation of the electrical safety circuit as well as the electrical and control
equipment for the heat supply and its auxiliary equipment shall be in accordance with EN 50156-1.
The appropriate levels of functional safety identified in the hazard analysis for the limiters shall be implemented.
NOTE 1 Typical Safety Integrity Level (SIL) requirements for boiler protective systems are not less than 2.
NOTE 2 It should be possible to stop the boiler by additional devices outside the boiler such as shut-off valve, emergency
shut-off, fire detectors, etc.
4.6.3 Functional check of all limiters shall be possible at any time during operation.
Where appropriate and if justified by the hazard analysis the functional check can be performed by simulation.
4.6.4 When a limiter activates, information shall be given to indicate which limiter has activated.
4.7 Feed lines and protection against feedwater backflow
4.7.1 Each feed line leading to the steam boiler or hot water generator shall be equipped with a protection device
against backflow and a shut-off device. If the shut-off device and the protection device against backflow are not
installed in direct connection to each other, pressure relieving shall be possible for the intermediate piping section.
A single once-through steam boiler in which the heat supply is cut off automatically in the case of feedwater failure,
requires neither a shut-off device nor protection device against backflow if the feed pump is of the positive
displacement type where it can be ensured that no dangerous backflow can occur.
4.7.2 Except for once-through boilers, the feed line shall be connected to the steam boiler or hot water generator
in such a way that, in the case of leakage of the protection device against backflow, the steam boiler cannot be
drained to below the highest point of the downcomers.
4.7.3 Feed pumps shall be capable of isolation from common suction or pressure lines.
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4.7.4 If there is a possibility of backflow through a feed pump, the suction line between the valve and the pump
shall be designed for full pressure or appropriate devices shall be installed to exclude the danger from closing the
isolating valve in the suction line.
4.8 Connection of steam boilers or hot water generators
Where a steam boiler or hot water generating plant has several steam boilers or hot water generators connected by
common lines and the shut-off devices in the steam or hot water and feed lines remain permanently connected with
these lines during inspection of the steam boilers or hot water generators, two shut-off devices with intermediate
venting shall be installed in each line. The shut-off devices shall be lockable in the closed position and be protected
against unintentional actuation.
4.9 Water quality
The water quality shall be at least in accordance with EN 12952-12 and the manufacturer's operating instructions.
4.9.1 Condensate in steam boiler plants
An assessment shall be carried out to identify if there is a risk that harmful matter (e.g. oil, grease, organic material,
acid, lye, seawater, hardness etc.) can enter with the condensate into the feed water system and/or into the boiler
that will compromise the safety of the boiler or the operation of the limiters.
If it is assessed that harmful matter can enter the condensate return to the feed water system, adequate monitoring
shall be installed which is able to detect the contamination.
4.9.2 Water circulating system in hot water generator plants
An assessment shall be carried out to identify if there is a risk that harmful matter (e.g. oil, grease, organic material,
acid, lye, seawater, hardness etc.) can enter the water circulating system that will compromise the safety of the
boiler or the operation of the limiters.

If it is assessed that harmful matter can enter the water circulating system, adequate monitoring shall be installed
which is able to detect the contamination.

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5 Special requirements for steam boilers
5.1 Requirements for pumps
5.1.1 Number of feed-water pumps
5.1.1.1 One feed pump shall suffice if the requirements of 4.3.3-1st or 3rd indent(s), are met. In the case of
failure of the feed pump e.g power source the heat supply shall be cut off automatically.
5.1.1.2 Steam boilers that do not meet the requirements of 4.3.3-1st or 3rd indent(s) shall be equipped with at
least two feed pumps.
5.1.2 Capacity of feed-water pumps
5.1.2.1 The steam boiler shall be provided with an adequate supply of feed water.
The feed pumps shall be capable of supplying the feedwater to the steam boiler at 1,1 times the maximum
allowable pressure, considering to geodetic high, dynamic pressure losses in the feedline and the boiler.
5.1.2.2 If more than one feed-water pump is required according to 5.1.1.2, the following shall apply:
a) In the case of failure of the feed pump with the highest capacity, the remaining feed pumps shall meet the re-
quirements of 5.1.2;
b) Two independent power sources shall be available. By exception, steam operation of all feed pumps from only
one steam main shall be permissible. The feed pumps shall be connected to the power sources in such a way
that in the case of failure of one power source the remaining feed pumps shall meet the requirements of
5.1.2.1. Where the pumps are electrically driven, one line per feed pump drive can suffice if the line can be
switched over to a separate independent electrical supply;
c) In the case of steam boiler plant of a unitized arrangement, it shall be permitted to rate the second feed pump
for reduced capacity if it is ensured that in the case of failure of the feed pumps rated for the allowable steam
output, the heat supply system is, at the same time, automatically adjusted to the reduced steam output. If wa-
ter is blown down, the quantity of blow down water shall be fully considered when rating the second feed
pump;
d) For natural and assisted circulation steam boilers, the stand-by pump shall have been put into operation if the
operating pump fails, before the water level has sunk below the lowest water level;
e) In the case of once-through steam generators, the stand-by pump shall have been put into operation, within a
time interval to be specified by the manufacturer, if the operating pump fails, or if the flow through the steam
boiler has fallen to below the minimum flow required, thusensuring that an inadmissible excess of the tempe-
rature is avoided.
The feed pumps shall be capable of supplying to the steam boiler both the feedwater quantities at maximum allow-
able pressure as specified in 5.1.2.1 and the feedwater quantity corresponding to the allowable steam output at
1,1 times the allowable working pressure.
If it is proved that the pressure relief devices are capable of discharging the steam generated in the case of excess
of the allowable working pressure by less than 10 %, a correspondingly lower factor than 1,1 can be used in the
calculation.
5.1.3 Circulating pumps
5.1.3.1 For forced circulation steam boilers one circulating pump shall suffice if in the case of failure of the
circulating pump e.g. power source, the heat supply is cut off and:
a) the requirements of 4.2.3-1st indent are met and there is no risk of local overheating of the circulation system;
or
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b) the requirements of 4.2.3-3rd indent are met; or
c) the steam boiler is only heated with gases not exceeding a temperature of 400 °C.
5.1.3.2 Forced circulation steam boilers not corresponding to 5.1.3.1 shall be equipped with at least two circu-
lating pumps. A common standby circulating pump can suffice for several forced circulation steam boilers of one
steam boiler plant, if it can be connected to each steam boiler.
5.1.3.3 An alarm system shall become effective in the case of failure of one circulating pump and whenever
the flow rate in the circulation system has fallen to a specified minimum value.
5.1.3.4 For the power sources of the circulating pumps 5.1.2.3 b) shall apply.
5.2 Isolating and drain devices
5.2.1 Each steam boiler shall be provided with sufficient devices by which it can be positively isolated from the
system. Except in the case of unitized arrangements such devices shall be located as close as possible to the
steam boiler.
Where duplicate isolating devices are installed in series, but not adjacent to each other, the intervening tubework
shall be provided with means for venting and condensate removal.
5.2.2 Steam boilers shall be equipped with drains. Such drains and the nozzles thereof shall be protected
against the effects of combustion gases. Self-closing blowdown devices shall be capable of being locked manually
in the closed position unless a further shut-off device is installed in the line.
5.2.3 Automatic devices by which the water level may be lowered to below LWL (see 5.3) shall only be used if
the following requirements are met.
The steam boiler shall comply with 4.2.3-3rd indent or the design of the heat supply system shall ensure that no
unacceptable evaporation of the water inside the steam boiler occurs due to the heat accumulated in the boiler
passes upon cut-off of the heat supply.
5.3 Lowest permissibl
...

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