Debris in gas pipe

[gary0862]

Hi,i was called out to a boiler breakdown, found the cause to be very fine metal filings/particles blocking the gas valve.cleaned out gas pipe with compressor,fitted new gas valve ,had national grid out to change meter and governor.all worke well for three weeks then same problem,any ideas.

 

[diamondgas]

:welcome: gary

Ya See long time back they use to fit filter governors to gas meters, nowerdays they don't.... The stuff is comong from the gas mains, there may have been some work done recently in the area that had dislodged whatever it is? Not a lot you can do except involve the gas supplier. Its like a silver equivalent of gold leaf and lines the inside of the gas pipes my thoughts are that it sometimes gets disturbed and hey presto! Cloggs up some unfortunate's gas valve! Thankfully they still fit a fine filter to most valves

 

[AWheating]

i was told it was carbon from dirty gas? have seen it a few times and some houses will have its gas carcus lined with it. Report it to the gas supplier.

 

[thewall83]

fit a filter to the gas after the meter. i have a customer whos gas valves need cleaning regularly . transco deny it is their probem but we changed the gas carcas in case it was the copper and it is still happening.

 

[tamz]

It is caused by the hydrogen sulphide in gas (the rotten egg smell) reacting with the copper and forming copper sulphide. The copper sulphide flakes off and if exposed enough can turn into what is called black dust.
The stuff they add to natural gas to give the "gas" smell, makes the problem worse.
It happens to some degree in all copper gas lines but some parts of the country seem more prone than others. The only way to stop it is run the gas in iron.
If you fit a filter it will need regular cleaning.

If you fancy a read, this study will explain it better.
http://www.hse.gov.uk/research/crr_pdf/2000/crr00287.pdf

 

[Mbear]

Black dust, there are filters for it. Im not overly sure how effective they are tbh.

They can ruin gas valves, especially zero governors