21/30431933 DC

This standard 21/30431933 DC BS ISO 4437-4. Plastics piping systems for the supply of gaseous fuels. Polyethylene (PE) is classified in these ICS categories:

• 75.200 Petroleum products and natural gas handling equipment
• 83.140.30 Plastics pipes and fittings for non fluid use

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 ISO/DIS 4437−2:2021 and ISO/DIS 4437-3:2021 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 ISO 4437 , provided that they have PE connections for butt fusion or electrofusion ends, including integrated material transition joints, conforming to ISO 4437-3:2021 .

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 ISO 4437 , 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:

1. a maximum operating pressure, MOP, up to and including 10 bar ¹

   ¹

   1 bar = 0,1 MPa =10⁵ Pa; 1 MPa = 1 N/mm².

   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.

2. an operating temperature between −20 °C to 40 °C.

ISO 4437 (all parts) covers a range of maximum operating pressures and gives requirements concerning colours.

This document covers valve bodies designed for connection with pipes with a nominal outside diameter d _n ≤ 400 mm.