I was once asked to look at and fix a leak on a cast iron pipe in the palace of Westminster (house of commons) it was a sloping pipe on a stairwell and may have given trouble for 5 years or more as the leak was emminating from a BSP plug that had been tightened into a cut thread in the side of the pipe. BSP is British standard pipe thread, that is usually a tapered male/female joint, the sealing material between the threads is cruhed as the taper closes up, now, cast iron pipe is not very ductile and so a tapered plug is not a good idea, too much pressure and the pipe splits longtitudinally and was the case here, I returned a day or two later and froze the pipe either side of the plug (8" diameter) many gallons of liquid nitrogen were needed for this operation, but draining water from the entire system could have taken days to achieve and even longer to fill agan, mainly due to access to locked offices limited by security, the plug was removed, the pipe polished, a Siddle clamp was installed that is about three feet long and is basically a rubber wrap with a stainless sheet cover and bolted along one side, freeze removed using oxy acetylene and Bob's your uncle, I charged a VERY large amount of money for this repair, since during the course of survey and doing the job, I learned that 8 (eight) prevous contractors had all shown up to investigate, only to fail to quote or even show up again, I was not prepared to price this job, knowing as I do what might be involved both work wise and personel wise, It was a shit job, involving a Liquid nitrogen tanker on red route outside (Westminster remember), five blokes, much carrying of kit down staircases, mega clean up of rusty and black heating water from a white painted stairwell with grey steps edged in yellow and general dealing with pathetic know nothing MOD and PSA officials all doubting your ability when their own is non existant. It was clear to me that they were desperate to find some one that could fix it, Me and (more importantly) my gang of men did so, PSA paid up (heavilly) after four months, I was on the point of taking gov.uk to court, which I would have done if another month had passed. If you know what your doing and no one else does or they cant be arsed, charge the bastards!
CLEM