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.