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Fire sprinkler systems often spring leaks because the thin pipes corrode,
says Pipe Sterilization of Scottsdale, Arizona, in WO 01/24836. Sprinkler
systems are tacked onto the end of a water supply and remain unused for years.
This creates a stagnant breeding ground for acid-producing and sulphate-reducing
bacteria trapped during manufacture. The bugs feed on oil left near the welds,
making pinhole leaks and rotten egg smells. The answer is to shut off the dead
end, and sterilise the joints with steam and ozone pumped through the pipes. So
even though the water stagnates, there is no life left to breed.