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.

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:

1. a)

   a maximum allowable operating pressure (PFA) up to and including 25 bar ¹

   ¹

   1 bar = 0,1 MPa = 10 ⁵  Pa; 1 MPa = 1 N/mm ².

   ;
   
   
2. b)

   an operating temperature of 20  °C as the reference temperature.

This document covers a range of maximum allowable operating pressures and gives requirements concerning colours.

This document is applicable to fittings of the following types:

1. 1.

   fusion fittings;

   1. a.

      electrofusion fittings;

   2. b.

      spigot end fittings (for butt fusion using heated tools and electrofusion socket fusion);

   3. c.

      socket fusion fittings (see Annex A);

2. 2.

   mechanical fittings;

   1. a.

      compression fittings;

   2. b.

      flanged fittings;

3. 3.

   fabricated fittings (see Annex B).