National Grid (power converter station)

Leak detection and PRV (Pressure Reducing Valve)

As a result of recurring poor pressure Water Audit were invited to undertake a study of the supply regime and advise on improvements in water efficiency for the site.

Various problems were found surrounding the fire main which had a pressurised system operating continuously.

This suggested down stream leakage as the operation was pressure controlled. Additionally, two leaks were found, under 415,000 volt transformers, on poorly installed black polyethylene supply pipes.

The rectification of these leaks was undertaken by specialist contractors due to the nature and sensitivity of the works.

In order to protect this particularly sensitive infrastructure a Pressure Reducing Valve (PRV) was installed at the commencement of the supply. The outlet pressure set to 2.5 bar representing a reduction from 4 bar.

This along with the supply repairs reduced the nightline by 4 m 3 per hour, a saving of £54k per annum.

A further benefit of the PRV installation was to increase the immediate network area pressure, reducing the number of low pressure complaint calls from South East Water customers in the area.