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).
99.60 Withdrawal effective
Mar 9, 2005