CEN/TC 235 - Gas pressure regulators and associated safety devices for use in gas transmission and distribution

This European Standard specifies constructional, functional, testing, marking, sizing and documentation requirements of gas pressure regulators:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from - 20  °C to +60 °C,
which operate with fuel gases of the 1st and 2nd  family as defined in EN 437:2003+A1:2009, used in the pressure regulating stations in accordance with EN 12186 or EN 12279, in transmission and distribution networks and also in commercial and industrial installations.
"Gas pressure regulators" hereafter will be called "regulators" except in the titles.
For standard regulators when used in pressure regulating stations complying with EN 12186 or EN 12279, the Annex ZA lists all applicable essential safety requirements of the European legislation on pressure equipment except external and internal corrosion resistance for applications in corrosive environment.
This document considers the following temperature classes/types of regulators:
-   temperature class 1: operating temperature range from −10 °C to 60 °C;
-   temperature class 2: operating temperature range from −20 °C to 60 °C;
-   type IS: (integral strength type);
-   type DS: (differential strength type).
This document applies to regulators which use the pipeline gas as a source of control energy unassisted by any external power source.
The regulator may incorporate a second regulator, used as monitor, complying with the requirements in this document.
The regulator may incorporate a safety shut off device (SSD) complying with the requirements of EN 14382.
The regulator may incorporate a creep (venting) relief device, complying with the requirements in Annex E and/or a vent limiter, complying with the requirements in Annex I.
This document does not apply to:
-   regulators upstream from/on/in domestic gas-consuming appliances which are installed downstream of domestic gas meters;
-   regulators designed to be incorporated into pressure control systems used in service lines ) with volumetric flow rate ≤ 200 m3/h at normal conditions and inlet pressure ≤ 5 bar;
-   regulators for which a specific document exists (e.g. EN 88-1 and EN 88-2, etc.);
-   industrial process control valves in accordance with EN 1349.
The normative Annex G of this document lists some suitable materials for pressure bearing parts, inner metallic partition walls, auxiliary devices, integral process and sensing lines, connectors and fasteners. Other materials may be used when complying with the restrictions given in Table 5.
Continued integrity of gas pressure regulators is ensured by suitable surveillance checks and maintenance. For periodic functional checks and maintenance it is common to refer to national regulations/standards where existing or users/manufacturers practices.
This document has introduced the reaction of the pressure regulators to the specified reasonable expected failures in terms of "fail close" and "fail open" pressure regulator types, but it should be considered that there are other types of failures whose consequences can bring to the same reactions (these risks are covered via redundancy as per EN 12186) and that residual hazards will be reduced by a suitable surveillance in use / maintenance.
In this document, both pressure regulators that can be classified as "safety accessories" by themselves (monitors) according to European legislation on pressure equipment as well as regulators that can be used to provide the necessary pressure protection through redundancy (e.g. pressure regulator with integrated safety shut-off device, pressure regulator + in-line monitor, pressure regulator + safety shut off device) are considered.
The provisions in this document are in line with the state of art at the moment of writing.

This document specifies constructional, functional, testing marking and sizing requirements and documentation of gas safety shut-off devices:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from -20 °C to +60 °C;
which operate with fuel gases of the 1st and 2nd family as defined in EN 437, used in the pressure regulating stations in accordance with EN 12186 or EN 12279, in transmission and distribution networks and also in commercial and industrial installations.
"Gas safety shut-off devices" will hereafter be called "SSDs" except in titles.
For standard safety shut-off devices when used in pressure regulating stations complying with EN 12186 or EN 12279, Annex ZA lists all applicable Essential Safety Requirements of Directive 2014/68/EU (PED).
This document considers the following temperature classes/types of SSDs:
-   temperature class 1: operating temperature range from -10 °C to 60 °C;
-   temperature class 2: operating temperature range from -20 °C to 60 °C;
-   functional class A: SSDs that close when damage to the pressure detecting element occurs or when external power fails and whose re-opening, is possible only manually;
-   functional class B: SSDs that do not close when damage to the pressure detecting element occurs but provide suitable and reliable protection and whose re-opening, is possible only manually;
-   type IS: (integral strength type);
-   type DS: (differential strength type).
SSDs complying with the requirements of this document may be declared as "in conformity with EN 14382" and bear the mark "EN 14382".
The material and functional requirements specified in this document may be applied to SSDs which use thermal energy or the effects of electrical energy to trip the operation of the closing member. For these SSDs the operational parameters are not specified in this document.
The SSD may incorporate a vent limiter, complying with the requirements in Annex J.
This standard for some paragraphs and sub clauses makes full reference to prEN 334:2016.
This document does not apply to:
-   SSDs upstream from/on/in domestic gas-consuming appliances which are installed downstream of domestic gas meters;
-   SSDs designed to be incorporated into pressure-regulating devices used in service lines  with volumetric flow rate ≤ 200 m3/h at normal conditions and inlet pressure ≤ 5 bar.
Continued integrity of safety shut-off devices is ensured by periodic functional checks. For periodic functional checks it is common to refer to national regulations/standards where existing or users/manufacturers practices.
This document considers the reaction of the SSDs functional class A to the specified reasonable expected failures in terms of "fail close" behaviour, but it should be consider that there are other types of failures whose consequences cannot bring to the same reactions (these risks are covered via redundancy as per EN 12186) and that residual hazards should be reduced by a suitable surveillance in use / maintenance.
In this document, both safety shut-off devices that can be classified as "safety accessories" by themselves according the Pressure Equipment Directive (2014/68/EU) as well as safety shut-off devices that can be used to provide the necessary pressure protection through redundancy (e.g. shutoff device integrated in a pressure regulator, shut-off device with a second shut-off device) are considered. Addition of environmental considerations;
The provisions in this document are in line with the state of art at the moment of writing.
This document does not intend to limit the improvement of actual provisions (materials, requirements, test methods, acceptance criteria, etc.) or the developing of new provisions for SSDs where they are suitable to ensure an equivalent level of reliability.

Tolerance of 9 months requested before UAP per CEN/TC 235 C02/2006.

Tolerance of 9 months before UAP per CEN/TC 235 res. C03/2006.

This European Standard specifies constructional, functional, testing, marking, sizing and documentation requirements of gas pressure regulators:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from - 20  °C to +60 °C,
which operate with fuel gases of the 1st and 2nd  family as defined in EN 437:2003+A1:2009, used in the pressure regulating stations in accordance with EN 12186 or EN 12279, in transmission and distribution networks and also in commercial and industrial installations.
"Gas pressure regulators" hereafter will be called "regulators" except in the titles.
For standard regulators when used in pressure regulating stations complying with EN 12186 or EN 12279, the Annex ZA lists all applicable essential safety requirements of the European legislation on pressure equipment except external and internal corrosion resistance for applications in corrosive environment.
This document considers the following temperature classes/types of regulators:
-   temperature class 1: operating temperature range from −10 °C to 60 °C;
-   temperature class 2: operating temperature range from −20 °C to 60 °C;
-   type IS: (integral strength type);
-   type DS: (differential strength type).
This document applies to regulators which use the pipeline gas as a source of control energy unassisted by any external power source.
The regulator may incorporate a second regulator, used as monitor, complying with the requirements in this document.
The regulator may incorporate a safety shut off device (SSD) complying with the requirements of EN 14382.
The regulator may incorporate a creep (venting) relief device, complying with the requirements in Annex E and/or a vent limiter, complying with the requirements in Annex I.
This document does not apply to:
-   regulators upstream from/on/in domestic gas-consuming appliances which are installed downstream of domestic gas meters;
-   regulators designed to be incorporated into pressure control systems used in service lines ) with volumetric flow rate ≤ 200 m3/h at normal conditions and inlet pressure ≤ 5 bar;
-   regulators for which a specific document exists (e.g. EN 88-1 and EN 88-2, etc.);
-   industrial process control valves in accordance with EN 1349.
The normative Annex G of this document lists some suitable materials for pressure bearing parts, inner metallic partition walls, auxiliary devices, integral process and sensing lines, connectors and fasteners. Other materials may be used when complying with the restrictions given in Table 5.
Continued integrity of gas pressure regulators is ensured by suitable surveillance checks and maintenance. For periodic functional checks and maintenance it is common to refer to national regulations/standards where existing or users/manufacturers practices.
This document has introduced the reaction of the pressure regulators to the specified reasonable expected failures in terms of "fail close" and "fail open" pressure regulator types, but it should be considered that there are other types of failures whose consequences can bring to the same reactions (these risks are covered via redundancy as per EN 12186) and that residual hazards will be reduced by a suitable surveillance in use / maintenance.
In this document, both pressure regulators that can be classified as "safety accessories" by themselves (monitors) according to European legislation on pressure equipment as well as regulators that can be used to provide the necessary pressure protection through redundancy (e.g. pressure regulator with integrated safety shut-off device, pressure regulator + in-line monitor, pressure regulator + safety shut off device) are considered.
The provisions in this document are in line with the state of art at the moment of writing.

This document specifies constructional, functional, testing marking and sizing requirements and documentation of gas safety shut-off devices:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from -20 °C to +60 °C;
which operate with fuel gases of the 1st and 2nd family as defined in EN 437, used in the pressure regulating stations in accordance with EN 12186 or EN 12279, in transmission and distribution networks and also in commercial and industrial installations.
"Gas safety shut-off devices" will hereafter be called "SSDs" except in titles.
For standard safety shut-off devices when used in pressure regulating stations complying with EN 12186 or EN 12279, Annex ZA lists all applicable Essential Safety Requirements of Directive 2014/68/EU (PED).
This document considers the following temperature classes/types of SSDs:
-   temperature class 1: operating temperature range from -10 °C to 60 °C;
-   temperature class 2: operating temperature range from -20 °C to 60 °C;
-   functional class A: SSDs that close when damage to the pressure detecting element occurs or when external power fails and whose re-opening, is possible only manually;
-   functional class B: SSDs that do not close when damage to the pressure detecting element occurs but provide suitable and reliable protection and whose re-opening, is possible only manually;
-   type IS: (integral strength type);
-   type DS: (differential strength type).
SSDs complying with the requirements of this document may be declared as "in conformity with EN 14382" and bear the mark "EN 14382".
The material and functional requirements specified in this document may be applied to SSDs which use thermal energy or the effects of electrical energy to trip the operation of the closing member. For these SSDs the operational parameters are not specified in this document.
The SSD may incorporate a vent limiter, complying with the requirements in Annex J.
This standard for some paragraphs and sub clauses makes full reference to prEN 334:2016.
This document does not apply to:
-   SSDs upstream from/on/in domestic gas-consuming appliances which are installed downstream of domestic gas meters;
-   SSDs designed to be incorporated into pressure-regulating devices used in service lines  with volumetric flow rate ≤ 200 m3/h at normal conditions and inlet pressure ≤ 5 bar.
Continued integrity of safety shut-off devices is ensured by periodic functional checks. For periodic functional checks it is common to refer to national regulations/standards where existing or users/manufacturers practices.
This document considers the reaction of the SSDs functional class A to the specified reasonable expected failures in terms of "fail close" behaviour, but it should be consider that there are other types of failures whose consequences cannot bring to the same reactions (these risks are covered via redundancy as per EN 12186) and that residual hazards should be reduced by a suitable surveillance in use / maintenance.
In this document, both safety shut-off devices that can be classified as "safety accessories" by themselves according the Pressure Equipment Directive (2014/68/EU) as well as safety shut-off devices that can be used to provide the necessary pressure protection through redundancy (e.g. shutoff device integrated in a pressure regulator, shut-off device with a second shut-off device) are considered. Addition of environmental considerations;
The provisions in this document are in line with the state of art at the moment of writing.
This document does not intend to limit the improvement of actual provisions (materials, requirements, test methods, acceptance criteria, etc.) or the developing of new provisions for SSDs where they are suitable to ensure an equivalent level of reliability.

TC - Addition of a footnote to text to Clause 1, last indent and change of sub-clause headings/numbering in 4.3, including update of concerned cross references; correction of class values in the inspection document

This document specifies constructional, functional, testing and marking requirements, sizing and documentation of gas safety shut-off devices used in the pressure regulating stations in accordance with EN 12186 or EN 12279:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from -20 °C to +60 °C,
which operate with fuel gases of the 1st and 2nd family in accordance with EN 437 in transmission and distribution networks and also in commercial and industrial installations.
"Gas safety shut-off devices" will hereafter be called "SSDs" except in titles.
For standard safety shut-off devices when used in pressure regulating stations complying with EN 12186 or EN 12279, Annex ZA lists all applicable Essential Requirements except the external corrosion resistance in case of environmental conditions where corrosion is likely to occur.
This document considers the following classes/types of SSDs:
temperature classes:
-   class 1: operating temperature range from -10 °C to 60 °C;
-   class 2: operating temperature range from -20 °C to 60 °C;
functional classes:
-   class A: SSDs that close when damage to the pressure detector element occurs (applicable to overpressure SSDs only) or when external power fails and whose re-opening, after an intervention for overpressure, is possible only manually;
-   class B: SSDs that do not close when damage to the pressure detector element occurs and whose re-opening, after an intervention for overpressure, is possible only manually;
SSDs types:
-   type IS: (integral strength type);
-   type DS: (differential strength type).
SSDs complying with the requirements of this document may be declared as "in conformity with EN 14382" and bear the mark "EN 14382".
The material and functional requirements specified in this document may be applied to SSDs which use thermal energy or the effects of electrical energy to trip the operation of the closing member. For these SSDs the operat

This document specifies constructional, functional, testing and marking requirements, sizing and documentation of gas pressure regulators used in the pressure regulating stations in accordance with EN 12186 or EN 12279:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from  20 °C to +60 °C,
which operate with fuel gases of the 1st and 2nd family in accordance with EN 437 in transmission and distribution networks and also in commercial and industrial installations.
"Gas pressure regulators" hereafter will be called "regulators" except in the titles.
For standard regulators when used in pressure regulating stations complying with EN 12186 or EN 12279, Annex ZA lists all applicable Essential Requirements except the external corrosion resistance in case of environmental conditions where corrosion is likely to occur.
This document considers the following classes/types of regulators:
-   class 1: operating temperature range from  10 °C to 60 °C;
-   class 2: operating temperature range from  20 °C to 60 °C;
-   type IS: (integral strength type);
-   type DS: (differential strength type).
This document applies to regulators which use the pipeline gas as a source of control energy unassisted by any external power source.
The regulator may incorporate a creep (venting) relief device, complying with the requirements in Annex F.
The regulators complying with the requirements of this document may be declared as "in compliance with EN 334" and bear the marking "EN 334".
This document does not apply to:
-   regulators upstream from/on/in domestic gas consuming appliances which are installed downstream of domestic gas meters;
-   regulators incorporated into pressure-regulating devices used in service lines  with volumetric flow rate <= 200 m3/h at normal conditions and inlet pressure <= 5 bar;
-   regulators for which a specific document exists (e.g. EN 88, etc.);
-   industrial process control valves in ac

This European Standard specifies the minimum requirements for elastomeric materials intended to be used as static seals, dynamic seals or diaphragms in the gas pressure regulators covered by EN 334 and in the safety devices for gas pressure regulating stations and installations covered by the corresponding European Standards, as well as the relevant test methods to assess these requirements.
This European Standard applies to elastomeric materials for use with gases of the first and second gas families to EN 437, for inlet pressures less than or equal to 100 bar, and in an operating temperature range between -10 °C, (or -20 °C when applicable), and +60 °C.
This European Standard also gives some additional characteristics and recommendations for their application likely to be requested for elastomers in the order specifications, and the corresponding test methods (see informative Annex A).
This European Standard only applies for type testing.

This document specifies constructional, functional, sizing, and testing requirements, also documentation and marking of gas safety shut-off devices used in the pressure regulating stations in accordance with EN 12186 or EN 12279:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from -20 °C to +60 °C,
which operate with fuel gases of the 1st and 2nd family in accordance with EN 437 in transmission and distribution networks and also in commercial and industrial installations.
"Gas safety shut-off devices" will hereafter be called "SSDs" except in titles.
The harmonized part of this document deals with standard safety shut-off devices used in pressure regulating stations complying with EN 12186 or EN 12279. For standard safety shut-off devices integral strength type when used in pressure regulating stations complying with EN 12186 or EN 12279, Annex ZA lists all applicable Essential Requirements except the external resistance to environmental conditions where corrosion occurs.
This document considers the following classes of SSDs:
temperature classes:
-   class 1: operating temperature range from -10 °C to 60 °C;
-   class 2: operating temperature range from -20 °C to 60 °C;
functional classes:
-   class A: SSDs that close when damage to the pressure sensing element occurs (applicable to overpressure SSDs only) or when external power fails;
-   class B: SSDs that do not close when damage to the pressure sensing element occurs or are able to be opened automatically by the pressure control system (applicable to overpressure SSDs only).
SSDs complying with the requirements of this document may be declared as "in conformity with EN 14382" and bear the mark "EN 14382".
The material and functional requirements specified in this document may be applied to SSDs which use thermal energy or the effects of electrical energy to trip the operation of the closing member. For these SSDs the operational parameters are n

This document specifies constructional and functional requirements, regulator sizing, testing, documentation and marking of gas pressure regulators used in the pressure regulating stations:
-   for inlet pressures up to 100 bar and nominal diameters up to DN 400;
-   for an operating temperature range from  20 °C to +60 °C,
which operate with fuel gases of the 1st and 2nd family in accordance with EN 437 in transmission and distribution networks and also in commercial and industrial installations.
"Gas pressure regulators" hereafter will be called "regulators" except in the titles.
The harmonised part of this document deals with standard gas pressure regulators used in pressure regulating stations complying with EN 12186 or EN 12279. For gas pressure regulators integral strength type when used in pressure regulating stations complying with EN 12186 or EN 12279, Annex ZA lists all applicable Essential Requirements except the external resistance to environmental conditions where corrosion occurs.
This document considers the following classes of regulators:
-   class 1: operating temperature range from  10 °C to 60 °C;
-   class 2: operating temperature range from  20 °C to 60 °C.
This document applies to regulators which use the pipeline gas as a source of control energy unassisted by any external power source.
The regulator may incorporate a creep (venting) relief device, complying with the requirements in Annex F.
The regulators complying with the requirements of this document may be declared as "in compliance with EN 334" and bear the mark "EN 334".
This document does not apply to:
-   regulators upstream from/on/in domestic gas consuming appliances which are installed downstream of domestic gas meters;
-   regulators in accordance with prEN xxxxxx (WI 00235003 under preparation by CEN/TC 235) that comply with both of the following characteristics:
-   volumetric flow rate £ 200 m3/h at normal conditions;
-   inlet pressure £ 5 bar;
-   regulators for which a specif

This European Standard specifies constructional, functional, sizing, and testing requirements, also documentation and marking of gas safety shut-off devices:
¾ for operating pressures up to 100 bar and nominal diameters up to DN 400;
¾ used at an operating temperature range from -20 °C to +60 °C which operate with fuel gases of the 1st and 2nd family according to EN 437 in transmission and distribution networks and industrial installations.
For operating pressures higher than 100 bar or nominal diameters DN > 400 or operating temperatures outside the range -20 °C to 60 °C, this standard can be considered as a guideline.
Gas safety shut-off devices will hereafter be called SSDs except in titles.
This European Standard considers the following classes of SSD:
a) Temperature classes:
¾ class 1: operating temperature range from -10 °C to 60 °C;
¾ class 2: operating temperature range from -20 °C to 60 °C.
b) Functional classes:
¾ class A: SSDs that close when damage to the pressure sensing element occurs (applicable to overpressure SSDs only) or when external power fails;
¾ class B: SSDs that do not close when damage to the pressure sensing element occurs or are able to be opened automatically by the pressure control system (applicable to overpressure SSDs only).

Migrated from Progress Sheet (TC Comment) (2000-07-10): UAP of 4 months (TC Res 6/1999) (CC/990831)

This European Standard specifies constructional and functional requirements, regulator sizing, testing, documentation and marking of gas pressure regulators: - for inlet pressures up to 100 bar, - used at an ambient temperature range from -20°C to +60°C which operate with fuel gases of the 1st and of the 2nd family in accordance with EN 437 in transmission and distribution networks and also in industrial installations. "Gas pressure regulators" hereafter will be called "regulators" except in the titles.