This document specifies the fittings made from polyethylene (PE) for buried or above ground applications, intended for the conveyance of water for human consumption, raw water prior to treatment, drainage and sewerage under pressure, vacuum sewer systems, and water for other purposes.
NOTE 1 The intended uses include sea outfalls, laid in water and connection between pipes suspended below bridges.
This document also specifies the test parameters for the test methods referred to in this document.
In conjunction with the other parts of the ISO 4427 series, this document is applicable to PE fittings, to joints with components of PE or other materials, intended to be used under the following conditions:
a) a maximum allowable operating pressure (PFA) up to and including 25 bar;
b) an operating temperature of 20 °C as the reference temperature.
NOTE 2 For other operating temperatures, guidance is given in ISO 4427-1:2019, Annex A.
This document covers a range of maximum allowable 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 installation practices or codes.
This document is applicable to fittings of the following types:
1. fusion fittings;
a. electrofusion fittings;
b. spigot end fittings (for butt fusion using heated tools and electrofusion socket fusion);
c. socket fusion fittings (see Annex A);
2. mechanical fittings;
a. compression fittings;
b. flanged fittings;
3. fabricated fittings (see Annex B).
 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.