CEN/TR 16395:2012
(Main)Gas Infrastructure - CEN/TC 234 Pressure Definitions - Guideline Document
Gas Infrastructure - CEN/TC 234 Pressure Definitions - Guideline Document
This Technical Report gives explanation on the pressure definitions used by the gas network operators with regard to the standards of CEN/TC 234 "Gas Infrastructure".
The European Standards of CEN/TC 234 comprise the functional requirements in the field of gas infrastructure from the input of gas into the on-shore transmission network up to the inlet connection of gas appliances, including transmission, distribution, storage, compression, pressure regulation and metering, installation, injection of non-conventional gases, gas quality issues and others.
Gasinfrastruktur - CEN/TC 234 Druckdefinitionen - Leitliniendokument
Dieser Technische Bericht gibt eine Erklärung der Druckdefinitionen, die die Gasnetzbetreiber in Hinblick auf die Normen des CEN/TC 234 "Gasinfrastruktur" anwenden.
Die europäischen Normen des CEN/TC 234 enthalten funktionale Anforderungen auf dem Gebiet der Gasinfrastruktur, von der Einspeisung des Gases in das Verteilungsnetz bis zum Anschluss des Gasgerätes, einschließlich Transport, Verteilung, Speicherung, Verdichtung, Regelung und Messung, Installation, Einspeisung nicht konventioneller Gase, Gasbeschaffenheiten und andere.
Infrastructures gazières - Définitions des pressions du CEN/TC 234 - Lignes directrices
Le présent Rapport technique donne des explications sur les définitions de pression utilisées par les opérateurs de réseau de gaz à l'égard des normes du CEN/TC 234 "Infrastructures gazières".
Les Normes européennes du CEN/TC 234 comprennent les exigences fonctionnelles dans le domaine des infrastructures gazières depuis l'entrée du gaz dans le réseau de transport terrestre jusqu’à la connexion d'entrée des appareils à gaz, comprenant le transport, la distribution, le stockage, la compression, les installations de régulation de pression et de comptage, l'injection de gaz non conventionnels, les problèmes de qualité de gaz et autres.
Infrastruktura za plin - Definicije tlaka v CEN/TC 234 - Smernice
To tehnično poročilo pojasnjuje opredelitve tlaka, ki jih uporabljajo upravljavci plinskega omrežja v zvezi s standardi odbora CEN/TC 234 »Infrastruktura za plin«. Evropski standardi odbora CEN/TC 234 zajemajo funkcionalne zahteve na področju infrastrukture za plin od vnosa plina v kopensko prenosno omrežje do dovodnega priključka plinskih naprav, vključno s prenosom, distribucijo, skladiščenjem, kompresijo, uravnavanjem in merjenjem tlaka, namestitvijo, vnosom nekonvencionalnih plinov, vprašanji kakovosti plina itd.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2013
Infrastruktura za plin - Definicije tlaka v CEN/TC 234 - Smernice
Gas Infrastructure - CEN/TC 234 Pressure Definitions - Guideline Document
Gasinfrastruktur - CEN/TC 234 Druckdefinitionen - Leitliniendokument
Infrastructures gazières - Définitions des pressions du CEN/TC 234 - Lignes directrices
Ta slovenski standard je istoveten z: CEN/TR 16395:2012
ICS:
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL REPORT
CEN/TR 16395
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
October 2012
ICS 01.040.23; 01.040.91; 23.040.01; 91.140.40
English Version
Gas Infrastructure - CEN/TC 234 Pressure Definitions -
Guideline Document
Infrastructures gazières - Définitions des pressions du Gasinfrastruktur - CEN/TC 234 Druckdefinitionen -
CEN/TC 234 - Lignes directrices Leitliniendokument
This Technical Report was approved by CEN on 24 June 2012. It has been drawn up by the Technical Committee CEN/TC 234.
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 Ref. No. CEN/TR 16395:2012: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Introduction .4
1 Scope .6
2 Normative references .6
3 Terms and definitions .6
3.1 Key pressure definitions used in CEN/TC 234 standards .6
3.2 Derived pressure definitions used in CEN/TC 234 standards .6
3.3 Commonly used pressure definitions in European product standards .7
4 Explanation of Gas pressure definitions for gas transport and distribution systems .7
4.1 General .7
4.2 Pressure demarcation .8
4.3 Operating conditions .8
4.3.1 Normal operating conditions .8
4.3.2 Gas pressure under incidental operating conditions .8
4.4 Design pressure .9
4.5 Test pressures .9
4.6 Equipment in the scope of the European Pressure Equipment Directive .9
5 Relationships between MOP, TOP and MIP and test pressures . 10
Annex A (informative) Examples of relationships between pressure designations . 11
Annex B (informative) Industrial installations according to EN 15001 . 13
Bibliography . 14
Foreword
This document (CEN/TR 16395:2012) has been prepared by Technical Committee CEN/TC 234 “Gas
Infrastructure”, the secretariat of which is held by DIN.
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.
Operating pressure levels of gas infrastructure differ from one country to another in the European Union. This
is due to many different factors, such as the history of gas systems, technologies and materials used and
technical constraints.
When beginning to draft the functional standards on gas infrastructure, CEN/TC 234 recognised various
pressure levels and ranges in the European member countries, which are to some extent laid down in national
laws.
To form a consensus for the standardisation work, all pressure levels used in Europe have been brought
together and classified in ranges. This subdivision in pressure levels should permit the manufacturers of
components to focus on a limited number of designs in order to reduce the costs.
Introduction
Background
The standards issued by CEN/TC 234 "Gas Infrastructure" contain a large number of definitions used for the
design, testing and operation of the different parts of the gas infrastructure.
This document clarifies the CEN/TC 234 concept behind the definitions and advises how to use the definitions
correctly and consistently. In order to further that goal, an inventory of existing definitions is compiled and the
primary definitions are identified.
This document also gives guidance for the selection of components falling into the scope of the European
Pressure Equipment Directive (PED) [15] and used in the gas infrastructure.
Apart from the issue of the consistency of the pressure definition in the standards, there is also the issue of
the pressure rating of equipment and systems. Other classifications (e.g. PN or class) do not necessarily
completely coincide with the classification as defined in the CEN/TC 234 standards.
Concept of pressure conditions
On one hand, three different sets of pressure conditions are to be considered:
conditions during testing and commissioning (P );
conditions during exceptional operating circumstances (P );
conditions during normal operation (P ).
where:
P > P > P
1 2 3
The maximum pressure levels related to these conditions are the topic of the primary definitions.
On the other hand, two other pressure conditions are used for specifying the system:
pressure on which design calculations are based (p );
A
pressure rating of the system (p ).
B
where
p > p
A B.
The relationship between p and P or P is not uniform in the different CEN/TC 234 standards. This situation
A 2 3
is confusing and undesirable. The recommended practice is stated in chapter 4.4 and 4.5 below and should
be considered when revising standards or developing new standards.
Piping versus pressure regulating installations
Only two out of the three aforementioned conditions apply when specifying piping:
conditions during testing and commissioning;
operating conditions.
Normally for piping no distinction is made between normal operating conditions and exceptional operating
conditions, as piping is a passive component. However, in gas infrastructure piping and pressure regulating
installations both are present. This necessitates identification of the “normal operating conditions” and
“exceptional operating conditions” of the pressure regulating installations and the “operating conditions” of the
piping.
1 Scope
This Technical Report gives explanation on the pressure definitions used by the gas network operators with
regard to the standards of CEN/TC 234 "Gas Infrastructure".
The European Standards of CEN/TC 234 comprise the functional requirements in the field of gas
infrastructure from the input of gas into the on-shore transmission network up to the inlet connection of gas
appliances, including transmission, distribution, storage, compression, pressure regulation and metering,
installation, injection of non-conventional gases, gas quality issues and others.
2 Normative references
Not applicable.
3 Terms and definitions
3.1 Key pressure definitions used in CEN/TC 234 standards
3.1.1
design pressure
DP
pressure on which design calculations are based
Note 1 to entry: A system designed for a design pressure (DP) can comprise components designed for a different
maximum allowable pressure (PS).
3.1.2
maximum operating pressure
MOP
maximum pressure at which a system can be operated continuously under normal operating conditions
Note 1 to entry: Normal operating conditions are: no fault in any device or stream.
Note 2 to entry: The set point of the regulator does not exceed MOP.
3.1.3
maximum incidental pressure
MIP
maximum pressure which a system can experience during a short time, limited by the safety devices
3.2 Derived pressure definitions used in CEN/TC 234 standards
3.2.1
operating pressure
OP
nominal pressure on which the system is operated
3.2.2
temporary operating pressure
TOP
pressure at which a system can be operated temporarily under control of regulating devices
3.2.3
test pressure
TP
pressure at which pressure tests are conducted
3.2.4
strength test pressure
STP
pressure applied to a system during strength testing
3.2.5
tightness test pressure
TTP
pressure applied to a system during tightness testing
3.2.6
combined test pressure
CTP
pressure applied to a system during combined testing, i.e. tightness and strength testing
3.3 Commonly used pressure definitions in European product standards
3.3.1
maximum allowable pressure
PS
maximum pressure for which the equipment is designed, as specified by the manufacturer
Note 1 to entry: Definition and requirements according Directive 97/23/EC (Pressure Equipment Directive - PED).
3.3.2
nominal pressure
PN xx
alphanumeric designation used for reference purposes related to a combination of mechanical and
dimensional characteristics of a component of a pipework system
Note 1 to entry: It comprises the letters PN followed by a dimensionless number.
[SOURCE: EN 1333, modified]
3.3.3
class xxx
alphanumeric designation used for reference purposes related to a combination of mechanical and
dimensional characteristics of a component of a pipework system
Note 1 to entry: It comprises the word "Class" followed by a dimensionless whole number.
[SOURCE: EN 1759-1, modified]
4 Explanation of Gas pressure definitions for gas transport and distribution
systems
4.1 General
The pressure levels in the system MOP, TOP and MIP are to be chosen by the network operator when
designing and operating its network according to its constraints and national regulations.
4.2 Pressure demarcation
For a pipeline system, the maximum pressure values will occur at the entrance of a pipeline section. However,
in case the gas stream is interrupted for any reason, the whole pipeline section will be subjected to the same
pressure level.
The demarcation line for different pressure levels are, in the case of gas pressure regulating stations, at the
1)
exit flange of the gas pressure regulator [EN 12186] and for compressor stations, at the entrance of the
compressor [EN 12583].
4.3 Operating conditions
4.3.1 Normal operating conditions
4.3.1.1 MOP – Maximum operating pressure
The most relevant information related to the pressure in a network is the maximum pressure at which the
system can be operated under normal conditions. This value is defined as the maximum operation pressure
(MOP).
The maximum set point of the operating pressure is MOP, considering the available accuracy classes and the
lock-up pressure of gas pressure regulators [EN 334] or other regulating devices. The instantaneous pressure
(peak level OP) in the system can be occasionally higher than MOP even under normal operating conditions.
4.3.1.2 OP – Operating pressure
OP is the pressure which occurs within a system under normal operating conditions, being the set point of the
pressure regulating system at the entry of a pipeline.
4.3.1.3 Peak level OP
For pipelines with MOP > 16 bar, the peak level OP is limited to 1,025 × MOP [EN 1594]. For pipelines with a
MOP up to and including 16 bars, no limit is given in EN 12007. However, for gas pressure regulating stations
for transport and transmission and gas pressure regulating installations on service lines, the allowed limits for
this peak level OP is given in EN 12186 and EN 12279; see Table 1.
4.3.2 Gas pressure under incidental operating conditions
4.3.2.1 General
In case of a fault in the pressure regulator or compressor, the safety system will ensure that the pressure in
the downstream system will not exceed a stated maximum value under any circumstance.
4.3.2.2 MIP – Maximum incidental pressure
The pressure value that may not be exceeded in the gas infrastructure, even under fault conditions, is called
MIP – maximum incidental pressure. The pressure safety system has to ensure that MIP is never ex
...
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