Introduction

WIS 4-03-01 Issue 1 March 2024 has been prepared by a Water UK authorised Task and Finish Group in consultation with the Water Industry and the British Plastics Federation Pipes Group.

It specifies the procedure for hydrostatic pressure testing of below ground water supply pipelines and sewer rising mains made of polyethylene (PE) pipes to BS EN 12201-2 or PE barrier pipes (Type A) to BS 8588.

It also specifies simplified procedures for the pressure testing of replacement sections of, and service connections to, below ground water supply pipelines and sewer rising mains made of PE pipes to BS EN 12201-2 or PE barrier pipes (Type A) to BS 8588.

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.

BS EN 805: 2000 permits the designer to specify a test procedure for pipes with viscoelastic behaviour. WIS 4-03-01 Issue 1 March 2024 specifies the UK test procedure for hydrostatic testing of below ground pressure pipelines constructed from polyethylene or polyethylene barrier pipes.

WIS 4-03-01 Issue 1 March 2024 replaces IGN 4-03-01 Issue 2 October 2015, which has been archived (withdrawn).

Caveats

Formatting error in 28/3/24 version corrected 3/4/24 (Mis-numbering as WIS 4-03-01 on odd numbered pages).

In Figure 3 the positioning of the flow meter will be amended following acceptance of user feedback. As currently shown the position of the flow meter would not record any flow unless the bleed tap was open. The intention is to reposition the flow meter between the pump and the vertical ‘stack pipe’.