Odd comment re British Gas

[Timbrook99]

A member of our family has a very newly installed Glow Worm 30SXi boiler which cuts out for no apparent reason. The local fitter has called in Glow Worm since it is under warranty. The Glow Worm person has ordered a new gas valve. Rather surprisingly, the GW man declared that he'd seen similar problems on three other boilers in the area and that he believed it was being caused by an additive which BG were adding to the gas so as to reduce leaks.

Questions: Is this plausible? Do BG dope the gas in this way? If BG do this, why will a new valve be any better? How reliable are Glow Worm's boilers, (I'm planning to instal a

30HXi)?

TB

[John]

I can't offhand imagine any gaseous additive which would be able to act as a leak sealer but there again I aren't a chemist perhaps one of our regulars can add something here?

I've never met a problem which could be ascribed to a gas borne additive. I have on very few occasions met with a fine powder being carried through a gas pipe and which slowly clogged the fine strainer situated in the inlet port of some gas valves. On two occasions this appeared to be a black (oxide?) which "might" have come from the inside of a copper pipe. On another which was in a large industrial (newish, 100mm steel gas pipe) installation there was a pale powder which some wag said would be salt from the North sea but which I would have thought more likely to be plaster or similar which had got into the pipes accidentally or otherwise during the construction phase of the job.

I'd say you had made a good choice there. I've installed a few and they have been no trouble either to install or service as time went by.

[Aidan]

I recall BG spraying the insides of the gas main in the street where I lived, about 15 years ago, to reduce leaks. I believe (i.e., I don't know the details) that this involved pushing a small plastic pipe, similar to a drain jetter into the mains to spray it. I didn't hear of any subsequent problems.

It seems it wasn't very effective, since they dug up the street and replaced the steel/CI mains with MDPE a year or two later. I don't know if they still use this technique.

It sounds like blarney to me.

[Ian White]

There's a core of historical truth if you go back far enough. Because coal (town) gas was made by a process involving steam, it contained significant water vapour. Natural gas did not, so it had to be deliberately humidified to prevent the packed pipe joints from drying out and leaking.

That problem is obviously disappearing as the distribution network moves towards plastic. No doubt plastic brings problems of its own, but there are limits to the things that can be added to the supply, given that it mustn't affect the calorific value, and any additive must be safe to be burnt in an open kitchen.

Come to think, a likely reason for the sudden presence of dust or powder is that new pipe-laying has required some temporary re-routeing of the supply, which has disturbed some old deposits.

[N. Thornton]

From: Timbrook99 ( [e-mail])

Even if it were true, gloworm boilers would still be required to operate on BG's gas. But I'm sure a few folk will believe it, and blame BG instead of gloworm.

NT

[tarquinlinbin]

BG dont add anything to gas because they dont transport it. Transco regularly drip feeds a chemical called Monoethyleneglycol into low pressure mains system as a leakage control measure but theyve done this for decades so its nothing new..