Introduction

IGN 4-03-01 Issue 2 October 2015 has been archived (withdrawn) following the publication of WIS 4-03-01 Issue 1 March 2024 Specification for hydrostatic pressure testing of polyethylene and polyethylene barrier water supply pipelines and sewer rising mains.

Polyethylene (PE) pipes exhibit viscoelastic (creep) behaviour when subject to changes in internal pressure. They require a different hydrostatic pressure testing method than pipes constructed from non-viscoelastic materials (e.g. ductile iron, steel, GRP). Manufacturers’ guidance on the hydrostatic pressure testing of PVC-O pipelines is that the material’s behaviour should be regarded as non-viscoelastic.

The scope of the IGN included the hydrostatic pressure testing of both viscoelastic and non-viscoelastic pipelines. Its guidance on non-viscoelastic materials was essentially the same as that contained in BS EN 805: 2000. Experience indicates that users of the IGN were often uncertain which document had priority and, within them, which hydrostatic test method to use for different materials. The need to remove this uncertainty was one of the main drivers for the IGN’s replacement.

The publication of the WIS dispels the uncertainty by providing the UK test procedure for the hydrostatic pressure testing of PE and PE barrier (i.e. viscoelastic) water supply pipelines and sewer rising mains. Given that the test method in the IGN for non-viscoelastic pipelines is essentially the same as that in BS EN 805: 2000 there is now no necessity for the IGN’s continuance.

Caveats

Some consultees have argued for the continuance of the IGN when specifying the testing of non-viscoelastic pipelines pending publication of the revised version of BS EN 805 (expected in late 2024). They assert users’ greater familiarity with the IGN than the BS. Until that time it is for designers / specifiers to determine whether they choose to reference BS EN 805: 2000 or IGN 4-03-01 Issue 2 October 2015 for the hydrostatic pressure testing of non-viscoelastic pipelines. After the revised version of BS EN 805 is published, only that document should be specified for hydrostatic pressure testing of non-viscoelastic water supply pipelines and sewer rising mains.