prEN 1555-4

This document specifies the characteristics of valves made from polyethylene (PE) for piping systems in the field of the supply of gaseous fuels.
It is applicable to isolating unidirectional and bi-directional valves with spigot ends or electrofusion sockets intended to be fused with PE pipes or fittings conforming to prEN 1555-2:2024 and prEN 1555-3:2024 respectively.
Valves made from materials other than PE, designed for the supply of gaseous fuels conforming to the relevant standards can be used in PE piping systems according to prEN 1555 (all parts), provided that they have PE connections for butt fusion or electrofusion ends, including integrated material transition joints, conforming to prEN 1555-3:2024.
It also specifies the test parameters for the test methods referred to in this document.
In conjunction with Parts 1, 2, 3 and 5 of prEN 1555, it is applicable to PE valves, their joints and to joints with components of PE and other materials intended to be used under the following conditions:
a) a maximum operating pressure, MOP, up to and including 10 bar  at a reference temperature of 20 °C for design purposes;
NOTE 1  For the purpose of this document and the references to ISO 8233, MOP is considered to be nominal pressure.
b) an operating temperature between −20 °C to 40 °C.
NOTE 2  For operating temperatures between 20 °C and 40 °C, derating coefficients are defined in EN 1555-5.
EN 1555 (all parts) covers a range of maximum operating pressures and gives requirements concerning colours.
NOTE 3  It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects, taking into account their particular requirements and any relevant national regulations and installation practices or codes.
This document covers valve bodies designed for connection with pipes with a nominal outside diameter
dn ≤ 400 mm.