This document specifies the characteristics of solid-wall oriented unplasticized poly(vinyl chloride) (PVC-O) fittings for piping systems intended to be used underground or above ground where protected from direct sunlight, for water supply, buried drainage, sewerage, treated wastewater and irrigation under pressure. This document is applicable to double sockets, repair couplings, reducers and to non-end load bearing elbows only. This document is not applicable to tees, flange adaptors, etc.

NOTE？For double sockets, repair couplings, and reducers, there are no special fittings designs for end-load bearing applications. However, restrained gaskets can be used for end-load bearing applications. In this case, the requirements of ISO 16422-5 are applicable.

This document also specifies the test parameters for the test methods referred to in this document.

In conjunction with ISO 16422-1 and ISO 16422-5, this document is applicable to oriented PVC-O pipes with or without an integral socket, intended to be used for the following:

a)？water mains and services lines;

b)？conveyance of water for both outside and inside buildings;

c)？drainage, sewerage and treated wastewater under pressure;

d)？irrigation under pressure.

This document is applicable to piping systems intended for the supply of water under pressure up to and including 25？°C (cold water), intended for human consumption and for general purposes as well as for wastewater under pressure.

This document is also applicable to components for the conveyance of water and wastewater up to and including 45？°C. For temperatures between 25？°C and 45？°C, see ISO 16422-2, Figure？C.1.

The piping system according to this document is intended for the conveyance of cold water up to pressure of 25？bar[1] and especially in those applications where special performance requirements are needed, such as impact loads and pressure fluctuations, up to pressure of 25？bar.