low inlet pressure

[tamz]

If you cut out a bit old pipe and bang it on the ground it will surprise you the pile of dust that comes out. Some big flakes too.
Worse in some parts of the country than others but it is always there to some extent. That is what the silvery grey coating on the inside of a gas pipe is. Transco are supposed to keep the level of H2S below a certain level to minimise it.

 

[mfgs]

I've seen this before quite a few times but never had a problem with it like you describe. Interesting to know what it is and why though, thanks Tamz.

I have seen the inside of gas pipes a bit grey before, but I have never seen soo much of it come loose like this.

 

[Nostrum]

Bizarrely and quite spooky, i had this problem today. The underlying fault was low working pressure at meter but this was possibly caused by this stuff as when I removed the gas valve it was choked with the stuff? Wondering if the boiler sucking on a restricted supply line may be dislodging this stuff?

Will let you know if the problem re-occurs.

 

[tamz]

Wondering if the boiler sucking on a restricted supply line may be dislodging this stuff?

I've never really thought about that before but it could be a problem with the zpg's