Water in gas pipes

[foxhole]

Local water mains burst , took out gas main which left 2000 with no gas, gas main filled with water,just had my pipes cleared and now has working gas supply. Are there likely to be any long term damage to appliances, boiler from extra moisture in the gas supply.

 

[easyflow]

You must live in Bexley, made me late for the past couple of days.
No long time effect and any effects are the responsibility of Thames water.

 

[foxhole]

Yes , Mrs found she had no gas morning of our ruby anniversary , had to use a camping stove to boil the spuds , but have electrics oven so guests did’nt go hungry, and have a gas bar- b- q.

Gas repair guy had me worried mistook my electric meter for the gas.!!

 

[gas112]

no ill affects, was involved in one incident with 100,000 gallons into the gas mains water coming out of cookers fires etc about 6000 premises affected no appliance needed changing.

 

[John D v2.0]

Water into the gas main sounds like a disaster, is a wonder it doesn't happen more often. What do they do, purge it out with a compressor? Presumably gas mains aren't laid to a fall nowadays.

 

[AdrianUK]

But how does the get in? If the gas main is 'live', surely the gas pressure (which is several BAR in the street main) would keep the water out of any burst pipe?

 

[John D v2.0]

The street main is up to 75millibar, there are higher pressures but presumably not in this case. A 3 bar has main is extremely dangerous even if it were not flammable, so they are presumably very carefully installed.

 

[reds42]

A couple of months ago I got into a conversation with a cadent engineer. I was walking along and noticed a generator chained to one of those posts marking service locations, then spotted the engineer a short distance away eating his lunch.

Turns out he had been sent out to trace the exact path of I believe he said an intermediate pressure gas line through a cemetery. The pipe was a steel one and the generator was being used to power an electrical signal onto the pipeline, which he could then detect accurately through the ground. I forget how many bar he said it was running at but it was quite a few. It is buried only about 3 feet down - you would not want to damage it digging graves!

He said the marker post was a smart one as well which automatically relayed information about the state of the pipe and the sacrificial anodes connected to it back to a control centre- quite nifty.

I asked him how easy it was to trace the plastic pipelines and apparently they regularly have to resort to digging trenches to find a pipelines precise location. Even though a trace wire to send a signal laid with the pipe would make finding it much easier in the future it isn’t done.

This particular gas line runs from Kendal and feeds areas all the way out towards Ambleside so supplies a biggish area. During the flooding from storm desmond a few years ago a bridge over a river that the gas line crossed was severely damaged and all that was left holding the bridge up was this pipeline - he said it caused rather a big panic!

He was also was telling me about a time the gas pipework covering most of Ambleside was full of water. Took a big team of people a long time to clear it all out. I think the water had go into the pipes up on a hillside and worked its way down through the system.

 

[foxhole]

Was a high pressure water main.Now they have sorted the gas out they are digging up pavements to clear any remaining water in main gas pipe .

 

[foxhole]

But how does the get in? If the gas main is 'live', surely the gas pressure (which is several BAR in the street main) would keep the water out of any burst pipe?

Gas would have been turned off when water main breached it .

 

[Hot&Cold]

Are there likely to be any long term damage to appliances, boiler from extra moisture in the gas supply.

only if water has entered the gas meter,internal installation and appliances.if that happens its the responsibility of the water company (not gas supplier) to rectify any water defect after the gas meter.

Back in the day it was done with a handheld force pump.
There is a set procedure for water in gas mains incidents,its not uncommon and is usually quickly rectified before compensation has to be paid out . the gas supply and water company keep their customers informed via updates (vulnerable customers will have been contacted first in person or by phone).

Recent sgn gas incident
https://www.sgn.co.uk/News/Incidents/Incident/

 

[gas112]

That amount of water there will be on going issues for months to come
the plastic mains take up contours underground and remaining pockets of water will move and fill up dips in the pipework turning off various streets . As these areas show up they will be dealt with ,

 

[Hot&Cold]

The gas transporter have or have contractors that utilise camera survey's via live main insertion to identify exact pipe locations where water is toughing or they just leave it and hope for the best

 

[gas112]

Pmsl . it will be left after getting as much as they can out just now ,there will be thousands of low points they are not going to be digging everywhere

 

[foxhole]

They stated we will get £30 per day for loss of use etc.
£150 in my case.