Denso Weathershield protection for Transco gas main
Denso Weathershield protection for Transco gas mainKeywords: Epoxy coatings, Coatings, Winn &Coales
A 50m over-ground section of a 600mm T gas main in Rotherham, UK, has been given long-term protection with Winn & Coales' Denso ST Epoxy and Weathershield coating systems in a recent maintenance programme (see Plate 3). There are several historical reasons for this section of the gas main being above ground. It is near a canal and a railway embankment, which has led to continuous wet soil conditions. Also, it runs close to a sheet metal works,where there are several culverts and pits in the factory grounds.
When Transco drew up its recent maintenance programme, a long-life coating system was specified. SITE Coatings Ltd of Doncaster, who won the contract to carry out the renovation work on behalf of Transco, specified the Winn &Coales' coating systems. Following mechanical wire brushing to remove all loose paint coatings, SITE Coatings applied two coats of ST Epoxy, followed by two coats of Weathershield.
Plate 3 The Transco gas main in Rotherham protected with Winn & Coales' Denso ST Epoxy and Weathershield coating systems
Denso ST Epoxy is a mastic coating which claims exceptional adhesion properties. According to Winn & Coales, it can be spray- or brush-applied to deliver long-term protection in a wide range of corrosive environments.
Weathershield is an acrylic-based material to give extra protection,particularly to prevent after-exposure to sunlight.
Winn & Coales also report on a second project; in this case Mowlem Marine is constructing a new berth for Scrabster Harbour Thurso Bay, for ferries to Stromness in Britain's Orkney Islands. Consulting engineers are the Babtic Group. Over 800 tie rods will be used in its construction and the contract for their manufacture, protection and supply has been awarded to Normanby Industries Ltd of Scunthorpe.
The tie rods, which vary in length from 7m to 18m are being given long term protection by wrapping with Winn & Coales' Denso Tape, followed by hot applied Densotherm CA Tape. Normanby Industries are also supplying a large number of couplings, which will also be protected with Denso Tape, and approximately 1,000 tie rod end caps in various sizes. The Denso Tapes are being applied mechanically using a Denso Wrapping Machine.
Denso Tape is a non-woven synthetic fibre fabric impregnated and coated with an adhesive compound based on petrolatum. Densotherm CA is used as a protective outerwrap for Denso Tape and is fully impregnated and coated with a flexible high melting point compound. It is softened with a gas torch before application and also to seal the overlaps.
Further details are available from: Winn & Coales (Denso) Ltd. Tel: +44(0) 20 8670 7511; Fax: +44 (0) 20 8761 2456.
