This document specifies the pipes 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;
— water for other purposes.
NOTE 1 The intended uses include sea outfalls, laid in water and pipes suspended below bridges.
Pipes complying with this document are not intended for the transport of water intended for human consumption in contaminated soils unless special consideration has been taken.
NOTE 2 For example, ISO 21004 provides an alternative solution for use in contaminated soils. See Reference  in the Bibliography.
This document specifies three types of pipe:
— PE pipes (outside diameter dn), including any identification stripes;
— PE pipes with co-extruded layers on either or both the outside and/or inside of the pipe (total outside diameter dn) where all layers have the same MRS rating;
— PE pipes (outside diameter dn) having a peelable and contiguous thermoplastics additional layer on the outside of the pipe (coated pipe).
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 pipes, their joints and to joints with components made of PE and 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 3 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 4 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.
 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.