Denso Tape System Protects National Grid Non-Return Valves

The contract for this project was carried out by the civil engineering company J Anderson & Son Ltd (JAS) based in Wath on Dearne, Rotherham, South Yorkshire. JAS has been supplying a service to National Grid for 35 years.

JAS began this project by removing the valve pit lids and arranging scaffold access so the existing bolts retaining the valves could be removed along with the old Denso Paste. They then brought in heavy cranes to lift out the existing valves and replace with new before National Grid bolted them back into place.

On completion of these works JAS then repacked the voids around the bolts with new Denso Paste followed by Denso Profiling Mastic to give a smooth uniform surface. Denso Tape was then applied in an overlapping format, followed by a final Denso PVC outerwrap.

Winn & Coales (Denso) Ltd’s Denso Paste is a soft brown petrolatum primer containing moisture displacing corrosion inhibitors. It does not dry, harden or crack.