oSIST prEN 12953-6:2023
(Main)Shell Boilers - Part 6: Requirements for equipment for the boiler
Shell Boilers - Part 6: Requirements for equipment for the boiler
This part of this European Standard specifies the minimum requirements for safety related equipment for shell boilers as defined in EN 12953-1, to ensure the boiler operates within the allowable limits (pressure, temperature, etc.) and if the limits are exceeded the energy supply shall be interrupted and locked out without manual (human) intervention at the boiler.
NOTE 1 The maximum time of operation without manual (human) intervention should be defined for each boiler system.
NOTE 2 Annex C (informative) gives recommendations of operation and testing of the boiler system with a maximum time of operation without manual (human) intervention of 72 hours.
Großwasserraumkessel - Teil 6: Anforderungen an die Ausrüstung für den Kessel
Chaudières à tube de fumée - Partie 6: Exigences pour l'équipement de la chaudière
Mnogovodni kotli - 6. del: Zahteve za opremo kotla
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 12953-6:2023
01-junij-2023
Mnogovodni kotli - 6. del: Zahteve za opremo kotla
Shell Boilers - Part 6: Requirements for equipment for the boiler
Großwasserraumkessel - Teil 6: Anforderungen an die Ausrüstung für den Kessel
Chaudières à tube de fumée - Partie 6: Exigences pour l'équipement de la chaudière
Ta slovenski standard je istoveten z: prEN 12953-6
ICS:
27.060.30 Grelniki vode in prenosniki Boilers and heat exchangers
toplote
oSIST prEN 12953-6:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 12953-6:2023
DRAFT
EUROPEAN STANDARD
prEN 12953-6
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2023
ICS Will supersede EN 12953-6:2011
English Version
Shell Boilers - Part 6: Requirements for equipment for the
boiler
Chaudières à tube de fumée - Partie 6: Exigences pour Großwasserraumkessel - Teil 6: Anforderungen an die
l'équipement de la chaudière 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-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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye 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
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12953-6:2023 E
worldwide for CEN national Members.
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Contents
European foreword . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 General requirements for steam boilers and hot water boilers . 11
4.1 Safeguards (safety valves) against excessive pressure . 11
4.2 Materials for valves, fittings, flanges and bolting . 11
4.3 Protective systems . 11
4.4 Energy supply . 12
4.4.1 General . 12
4.4.2 Start up . 13
4.4.3 Normal shutdown . 13
4.5 Flue-gas heated economizers. 13
4.6 Drain and blowdown devices . 13
4.7 Water quality . 14
4.8 Water quality protection . 14
4.8.1 Conductivity in steam boiler water . 14
4.8.2 Condensate in steam boiler plants . 15
4.8.3 Water circulating system in hot water boiler plants . 15
4.8.4 Make-up water or feed water . 15
4.9 Furnace temperature monitoring system . 16
5 Special requirements for steam boilers . 17
5.1 Water level indication . 17
5.2 Steam pressure and temperature indication . 20
5.3 Valves for connections . 20
5.3.1 Steam outlets . 20
5.3.2 Feed pipe connections . 20
5.4 Feed water supply . 21
5.5 Feed water control . 21
5.6 Limiting and monitoring devices. 21
5.6.1 Low and high water level protection . 21
5.6.2 Pressure limitation . 22
5.6.3 Temperature limitation . 22
5.6.4 Flow monitoring device . 22
5.7 Electrically heated steam boilers . 22
6 Special requirements for hot water boilers . 23
6.1 Hot water generating systems . 23
6.2 Expansion and feed lines for open vented systems . 25
6.3 Water supply . 26
6.4 Water level indication . 26
6.5 Limiting and monitoring devices. 27
6.5.1 Low water protection . 27
6.5.2 Pressure and temperature limitation . 27
6.5.3 Flow monitoring device . 27
6.5.4 High water level protection . 28
6.6 Vent valves . 28
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6.7 Pressure and temperature indication . 28
6.8 Electrically heated hot water boilers . 28
6.9 Parallel mode of operation of hot water boilers . 29
7 Operational aspects including maintenance and testing . 29
8 Alarms and monitoring from the boiler plant . 30
Annex A (informative) Typical examples of steam and hot water boiler systems . 31
A.1 General . 31
A.2 Key to figures. 31
A.3 Plant with open vented system . 33
A.4 Plant with closed system . 34
A.4.1 Hot water system with external pressure generating and expansion system . 34
A.4.2 Hot water system with internal pressure generating and expansion system - Steam
cushion in the boiler . 35
A.4.3 Steam boiler . 36
A.5 Superheater and economizer . 37
A.5.1 Superheater . 37
A.5.2 Economizer . 38
Annex B (informative) Dimensioning of expansion space . 39
B.1 General . 39
B.2 Required data . 39
B.3 Formulas for dimensioning . 40
Annex C (informative) Aspects of boiler operation . 42
C.1 General . 42
C.2 Maintenance . 42
C.3 Boiler operation and testing . 42
Annex D (informative) Drain and blowdown devices. 47
D.1 General . 47
D.2 Design of the drain and blowdown devices . 47
Annex E (informative) Alarms and monitoring from the boiler plant. 49
E.1 General . 49
E.2 Conditions for alarms and monitoring . 49
Annex F (normative) Requirements for monitoring devices . 52
F.1 General requirements for monitoring devices . 52
F.1.1 General . 52
F.1.2 Components . 52
F.1.3 Materials and design . 52
F.1.4 Electrical equipment . 54
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F.1.5 Test procedure . 55
F.1.6 Marking . 55
F.1.7 Operating instructions . 55
F.2 Additional requirements for water monitoring devices. 55
F.2.1 Functional requirements. 55
F.2.2 Special requirements for water hardness monitoring devices . 56
F.2.3 Special requirements for devices for detecting and monitoring water for ingress of
harmful foreign matter . 56
F.2.4 Special requirements for water conductivity monitoring devices. 57
F.3 Additional requirements for flow monitoring devices . 57
F.3.1 Design . 57
F.3.2 Examination of functional capability . 58
Annex G (informative) Typical examples for expansion system . 60
G.1 General . 60
G.2 Key to figures . 60
G.3 Recommendations for expansion system. 61
G.4 Expansion and pressure holding for hot water boiler system . 62
G.4.1 Pressure pump-controlled system with pressureless membrane type expansion
vessel . 63
G.4.2 Pressure pump-controlled system with open expansion vessel . 64
G.4.3 Membrane type expansion vessel with pre-pressurized gas cushion. 65
G.4.4 Membrane type expansion vessel with controlled gas cushion . 66
G.4.5 Closed expansion vessel with pre-pressurized gas cushion . 67
G.4.6 Closed expansion vessel with gas or steam cushion. 68
Annex H (informative) Significant technical changes between this European Standard and
the previous edition . 69
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU aimed to be covered. 70
Bibliography . 72
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European foreword
This document (prEN 12953-6:2023) 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 12953-6:2011.
Annex H provides details of significant technical changes between this document and the previous
edition.
The series concerning shell boilers 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: Workmanship and construction of pressure parts of the boiler
— Part 5: Inspection during construction, documentation and marking of pressure parts of the boiler
— Part 6: Requirements for equipment for the boiler
— Part 7: Requirements for firing systems for liquid and gaseous fuels for the boiler
— Part 8: Requirements for safeguards against excessive pressure
— Part 9: Requirements for limiting devices of the boiler and accessories
— Part 10: Requirements for boiler feed water and boiler water quality
— Part 11: Acceptance tests
— Part 12: Requirements for firing systems for solid fuels for the boiler
— Part 13: Operating instructions
Although these parts can be obtained separately, it should be recognized that the parts are inter-
dependent. As such, the design and manufacture of shell boilers requires the application of more than
one part in order for the requirements of the standard to be satisfactorily fulfilled.
NOTE A “Boiler Helpdesk” has been established in CEN/TC 269 which can be contacted for any questions
regarding the application of the European Standards series EN 12952 and EN 12953 see the following website:
http://www.boiler-helpdesk.din.de.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral part
of this document.
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1 Scope
This document specifies the minimum requirements for safety related equipment for shell boilers
(generator and/or assemblies) as specified in EN 12953-1:2012, to ensure the boiler operates within the
allowable limits (pressure, temperature, etc.) and if the limits are exceeded the energy supply is
automatically interrupted and locked out, irrespective of the degree of intervention.
NOTE 1 For this document, the term “boiler” is applicable for generator and/or assemblies.
NOTE 2 The maximum time of operation without manual (human) intervention can be specified for each boiler
system.
NOTE 3 Annex C gives recommendations of operation and testing of the boiler system with a maximum time of
operation without manual (human) intervention of 24 h and 72 h.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 ISO 5167-1:2022, Measurement of fluid flow by means of pressure differential devices inserted in
circular cross-section conduits running full - Part 1: General principles and requirements (ISO 5167-1:2022)
EN 12953-1:2012, Shell boilers - Part 1: General
EN 12953-2:2012, Shell boilers - Part 2: Materials for pressure parts of boilers and accessories
EN 12953-3:2016, Shell boilers - Part 3: Design and calculation for pressure parts
EN 12953-7:2002, Shell boilers - Part 7 : Requirements for firing systems for liquid and gaseous fuels for the
boilers
EN 12953-8:2001, Shell boilers - Part 8: Requirements for safeguards against excessive pressure
1
prEN 12953-9:2023, Shell boilers — Part 9: Requirements for limiting devices of the boiler and accessories
EN 12953-10:2003, Shell boilers - Part 10 : Requirements for feedwater and boiler water quality
EN 12953-12:2003, Shell boilers - Part 12: Requirements for grate firing systems for solid fuels for the boiler
EN 12953-13:2012, Shell boilers - Part 13: Operating instructions
EN 14597:2012, Temperature control devices and temperature limiters for heat generating systems
EN 50156-1:2015, Electrical equipment for furnaces and ancillary equipment - Part 1: Requirements for
application design and installation
2
EN 60529:1991, Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989)
1
At draft stage.
2
Document impacted by A1:2000 and A2:2013.
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EN 60730-1:2016, Automatic electrical controls - Part 1: General requirements
EN 60747-5-2:2001, Discrete semiconductor devices and integrated circuits - Part 5-2: Optoelectronic
devices - Essential ratings and characteristics
EN 61140:2016, Protection against electric shock - Common aspects for installation and equipment
EN 61558-2-6:2009, Safety of transformers, reactors, power supply units and similar products for supply
voltages up to 1 100 V - Part 2-6: Particular requirements and tests for safety isolating transformers and
power supply units incorporating safety isolating transformers
EN 61558-2-16:2009, Safety of transformers, reactors, power supply units and similar products for supply
voltages up to 1 100 V - Part 2-16: Particular requirements and tests for switch mode power supply units
and transformers for switch mode power supply units
ISO 2186:2007, Fluid flow in closed conduits — Connections for pressure signal transmissions between
primary and secondary elements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12953-1:2012 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
controls
devices used for maintaining the variable to be controlled (pressure, temperature, etc.) at a specific value
(set point)
3.2
monitoring system/devices
system which checks given parameters and draws attention to those which are outside normal operating
limits but which are below the limiting values determined by the hazard and risk analysis and described
e.g. in the operation manual. Normal operating conditions of the process can be restored either directly
by the system or by a boiler attendant depending on the individual requirements
3.3
safety accessories
devices designed to protect pressure equipment against the allowable limits being exceeded, including
devices for direct pressure limitation, such as safety valves, bursting disc safety devices, buckling rods,
controlled safety pressure relief systems (CSPRS), and limiting devices, which either activate the means
for correction or provide for shutdown or shutdown and lockout, such as pressure switches or
temperature switches or fluid level switches and safety related measurement control and regulation
(SRMCR) devices
Note 1 to entry: Taken from PED 2014/68/EU.
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3.4
pressure accessories
devices with an operational function and having pressure-bearing housings
Note 1 to entry: Taken from PED 2014/68/EU.
3.5
limiter
limiting device
safety accessory which, on reaching a limiting value (water level, pressure, temperature, flow, water
quality), is used to interrupt and lock out the energy supply
Note 1 to entry: A limiter is an element of a safety device and a safety accessory for shell boilers as specified in
the Pressure Equipment Directive 2014/68/EU, Article 2, Clause 4. A limiter contains a sensor, possibly a sensor
control unit and ends at the output contact. The following safety logic and actuating element are not components of
this part of the standard, see prEN 12953-9:2023, Figure A.1.
Note 2 to entry: A limiting device comprises
— a measuring function and
— optional with a display and
— an activation function for correction, or shut-down, or safety shut-down and fault shut-down, and which
is used to carry out safety related functions as specified in the PED, on its own or as part of a safety (protective)
system (e.g. sensors, limiters). If this is achieved by multichannel systems, then all items or limiters for safety
purposes are included within the safety (protective) system.
3.6
lock-out
safety shut-down condition of the protective device, such that a restart can only be accomplished by a
manual reset of the limiter or by a manual reset of the safety logic on site and by no other means
3.7
functional check
testing of the safety device to ensure it performs its intended function
3.8
electrically heated boilers
boilers in which water is heated by an electric current flowing between electrodes or by
immersion heaters
3.9
expansion vessels
vessels to compensate for temperature dependent changes in water volume of hot water boilers
— closed expansion vessels are pressurised
— open expansion vessels are vented to atmospheric pressure and are not pressurised
3.10
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 boilers can be operated
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3.11
maximum allowable temperature (TS)
maxi
...
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