Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
Leakless in Seattle
Leakless in Seattle
Keywords: Seattle Public Utilities, Pipes, Coatings, Iron
The performance of pipework 6,000 miles away in the salt-laden glacial clay of Gothenberg, Sweden, has helped the Seattle Public Utilities (SPU) to choose a new alternative for the longer term protection from corrosion of its ductile iron water supply pipes.
The acidic nature of the Seattle soil and other environmental concerns inspired a world-wide search by Seattle engineers, unhappy with the performance of traditional protection systems.
The solution identified in Gothenburg by SPU engineers Jeff Pimental and Charlie Madden is PPA571, a high performance coating developed by Plascoat.
Plascoat reports that it has collaborated closely with innovative coaters SPC of Seattle in adapting the solution to the Seattle situation, where PPA has been fast tracked into SPU's specification for its current construction programme. This has enabled SPU to use PPA571 in a major project which will involve the replacement of approximately 21,000 feet of ductile iron pipe ranging from four to 24 inches in diameter.
The Plascoat material claims extended service life and is said to have proven itself in applications right around the world. PPA571 is currently said to be winning over water authorities throughout Europe, with approvals for coating both drinking and waste water pipes and fittings.
Plascoat suggests that further evidence supporting the value of the thermoplastic powder coating has come from the harsh environment of the Arizona desert. There the Plascoat PPA571 coating has overcome a chronic leakage problem on a ferric cure line in the copper leaching operation at Cyprus Miami Mining Corporation.
The pipes and couplings have to contend with the internal corrosive effect of a cure solution containing sulphuric acid and chlorides and external climatic and environmental extremes including temperatures in excess of 40°C and very strong UV rays.
Details available from: Plascoat Systems. Tel: +44 (0) 1252 733777.