Refillable lpg bottle outlet shut off valve leak

[Steve N Tracy]

Hi had 2 motorhomes serviced today by a mobile fitter, on both vans he reported the gas bottle isolator valves had a leak bye and were not shutting off correctly, one was a Alugas system and one a Gas it system, he did show me what was happening on the gauge and we tried it with a Calor bottle connected and it did not occur, but I find it hard to imagine that 2 diffirent 2 year old lpg systems would have the same fault, anybody came across this before?

 

[donkey]

Hi
As I understand it, there is a possibility of gas being 'stored' in liquid deposits within the system. There have been many instances of contaminants causing problems in gas systems, such as gumming up regulators. It is this gum, in a semi liquid state that can store the gas.
When your engineer tests your system, he no doubt turns off all taps and monitors his gauges. In your two cases he noticed a rise in pressure and assumed the gas flow taps were leaking. However, it could have been 'stored' gas being liberated that gave the increase in pressure.
If so, then a suitable time interval with the system vented to atmosphere, should enable the check to be carried out to confirm his findings.
Geoff

 

[Basildog]

I think I spoke to you at Autogas 2000 about this issue did you have any luck with resolving the suspected let-by ?

 

[Steve N Tracy]

Yes it was me, and no not really we did a leak test and no bubbles, the strange thing is it did not occur when we tried it with a Calor bottle, but I still find it hard to understand why the issue occurs with 2 diffirent 2 year old refillable systems 1 Alugas and 1 Gas it, and why it was not picked up on the service last year.

 

[Basildog]

Yes it was me, and no not really we did a leak test and no bubbles, the strange thing is it did not occur when we tried it with a Calor bottle, but I still find it hard to understand why the issue occurs with 2 diffirent 2 year old refillable systems 1 Alugas and 1 Gas it, and why it was not picked up on the service last year.

Over tightening of the shut off valve can cause some let by over time , also the valves can pick up debris on the face , I actually have a valve on my desk with a particle of rust on the face .
Calor cylinders can let by too but also as previously mentioned it’s also easy to produce false readings for several different reasons.
Also Motorhome/ caravan systems are such small volume the pressure fluctuations can seem extreme .

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[Steve N Tracy]

Over tightening of the shut off valve can cause some let by over time , also the valves can pick up debris on the face , I actually have a valve on my desk with a particle of rust on the face .
Calor cylinders can let by too but also as previously mentioned it’s also easy to produce false readings for several different reasons.
Also Motorhome/ caravan systems are such small volume the pressure fluctuations can seem extreme .

I rather suspect it is some kind of operator error, as I said we cannot detect any leak bye on either system, my son in law with the motorhome that the Gas it system owns his own gas instalation company, so has a gas test gauge we will rerun our own tests when we have time.

 

[mike mcglynn]

I had 3 separate gas leaks on my Gasit system on an 18 month old van , I was told by the repair guy at the dealers this must have been fitted by a gorilla as every connection was over tightened even on /the bbq connection had split the nut from pipe to fitting .

 

[Pausim]

As I understand it, there is a possibility of gas being 'stored' in liquid deposits within the system. There have been many instances of contaminants causing problems in gas systems, such as gumming up regulators. It is this gum, in a semi liquid state that can store the gas.

This was the problem when my Alugas cylinder was accused of leak by. The gum in the bottom the filter collector bowl was bubbling away gently. I now make sure the bowl is cleaned before it goes in for a hab check, no more problems.

 

[Basildog]

This was the problem when my Alugas cylinder was accused of leak by. The gum in the bottom the filter collector bowl was bubbling away gently. I now make sure the bowl is cleaned before it goes in for a hab check, no more problems.

Yes for some reason the caravan fitters can’t seem to get their heads around how to check if a cylinder valve is actually letting by !
Not that difficult to remove any pigtails to release all pressure and then give the cylinder valves a test with LDF or even put the pigtail in water for a while you’ll soon know if it’s letting by