Three water companies choose Denso protection

Citation

(1999), "Three water companies choose Denso protection", Anti-Corrosion Methods and Materials, Vol. 46 No. 2. https://doi.org/10.1108/acmm.1999.12846bab.008

Three water companies choose Denso protection

Methods

Three water companies choose Denso protection

Keywords Coatings, Denso, Pipelines

South Staffs Water plc are looking to extend the life of protective coatings on more than a hundred pipebridges in their area, and thereby reduce maintenance manhours.

The first project in this programme was the recoating of the 50m pipebridge that carries a 27inch treated water main over the River Tame at Tamworth. In the past this had to be repainted every four or five years to ensure adequate protection from corrosion.

Following a study of a number of the latest protective coatings systems now available, South Staffs Water chose Winn & Coales' recently introduced Denso Protal ST epoxy mastic. This is a surface tolerant coating with exceptional adhesion properties which can be brush or spray applied to deliver long-term protection in a wide range of corrosive environments.

The work was carried out by Ian Neale Contracting of Coventry, who first removed the previous coating by wire brushing and scraping. They then brush-applied two coats of Denso Protal ST followed by a top coat of Protal 3080, a marine alkyd gloss finish.

South Staffs Water say that they have every confidence that the new Winn & Coales Denso Protal ST system will now give them the required minimum ten years' protective service.

As part of its policy of upgrading water supplies and the treatment of waste water, Yorkshire Water is constructing a new waste water treatment works at Goole. The plant is being designed and built by Babcock Water Engineering Ltd.

The transfer pipeline contains a total of 562 Stanton integral socket and spigot pipework joints, some up to 600mm diameter, plus a number of mechanical joints (Plate 4). Sub-contractors Dobson Civil Engineers Ltd have protected all joints with Winn & Coales Denso Profiling Mastic followed by Densoclad 70 tape to a water industry P2 specification.

Densoclad 70 is a robust heavy duty tape specifically designed for the protection of medium to large diameter pipe and welded joints. The tough pvc backing combined with a polymer bitumen adhesive ensures complete protection against hostile environments, including immersed conditions, as well as resistance to damage by impact during backfill of the pipe trench.

Plate 4 Protecting a joint at Goole Waste Water Treatment Works with Denso Profiling Mastic and Densoclad 70 tape

Winn & Coales Denso protection has also been chosen for all the joints, including flange joints for washouts on a new 14.5km potable treated water pipeline just completed for Three Valleys Water. It is part of a drought contingency plan for Three Valleys in North Essex and Hertfordshire drawn up by consultants GU Partnership. The work has been carried out by contractors JBS Construction and R.E. Docwra.

The new line is a mixture of 300mm and 400mm ductile iron pipe. A 14.5km length runs from Lowerfield pumping station via Wendons Ambo pumping station near Saffron Walden to Uttlesford Bridge.

Consultants GU Partnership specified P1 protection to all the joints to give long life Protection. This consists of Denso Profiling Mastic to soften the joint profile overwrapped with Denso Tape.

Details from Winn & Coales (Denso) Ltd. Tel: +44 (0) 181 670 7511; Fax: +44 (0) 181 761 2456.