This document specifies the characteristics of valves made from unplasticized polyamide (PA-U) in accordance with ISO 16486-1, intended to be buried and used for 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 PA-U pipes or fittings conforming to ISO 16486-2 and ISO 16486-3 respectively.
Valves made from material other than unplasticized polyamide designed for the supply of gaseous fuels conforming to the relevant standards are permitted to be used in PA-U piping systems according to the ISO 16486 series provided they have relevant PA-U connections for butt fusion or electrofusion ends (see ISO 16486-3). The component, i.e. the complete valve, is required to fulfil the requirements of this document.
This document also specifies the test parameters for the test methods it describes.
In conjunction with ISO 16486-1, ISO 16486-2, ISO 16486-3 and ISO 16486-5, this document is applicable to PA-U valves and their joints and to joints with components of PA-U and other materials intended to be used under the following conditions:
a) a maximum operating pressure (MOP) of up to and including 18 bar, or limited to 16 bar under regional CEN requirements, 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 of -20 °C to 40 °C;
NOTE 2 For operating temperatures between 20 °C and 40 °C, derating coefficients are specified in ISO 16486-5.
This document covers valves for pipes with a nominal outside diameter, dn, = 400 mm.
 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm².