Truma gas regulator failure. (1 Viewer)

[andy63]

I acquired a gas regulator a while back that had failed.. first symptoms were a reduced flow and then it just shut down..
Its the model fitted with the secumotion and a reset button..
Ive opened it up and they appear fairly basic so was wondering how it failed..
Nothing obviously wrong with the mechanism ..
The only thing that is apparent is the inlet or 1st stage reduction seems to be blocked when compared to another regulator... ie blowing air through it...
Not that scientific i know
Im assuming the rubber valve seat must have swollen (and blocked the flow ) after been contaminated with the residue from the gas , but there wasnt a lot of that present..
If anyone knows of the supposed reason for them failing id be interested..
Like i say there doesnt appear to be a lot to go wrong in them..
Again some pictures..

Ist stage side showing the residue present..

2nd stage side..

And another view of 2nd stage mechanism

 

[smithy184]

Had the same problem on the same regulator a few years ago and it was the residue from the gas that had built up and blocked it. Fitted new regulator, problem solved. Not competent enough to strip down and clean myself. Fitted a standard regulator seem to recall the cost about £60.

 

[TerryL]

It's the residue that does it, a well-reported problem in the past that doesn't seem to have reared its head recently.

Only solution is a new regulator I'm afraid - I always carry a spare. Some recommend not using a Truma for replacement but I think they've now got the problem sorted.

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[andy63]

Not competent enough to strip down and clean myself.

Nor am i ... they have to be cut open. totally non serviceable..

It's the residue that does it,

It most probably is the residue that kill it but not by blocking anything itself as all the passages and orifices are clear... im sssuming it must have caused the rubber valve seat to swell ..the movement between opening and closing the inlet port can be measured in thousandths of an inch so it wouldnt take much expansion of the rubber..
Andy..

 

[Debs]

Looks familiar @andy63

 

[andy63]

Looks familiar @andy63

Bit late if you want it back

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[Debs]

Bit late if you want it back

Nope the new one is all fine & dandy thank you

 

[andy63]

Nope the new one is all fine & dandy thank you

Thats great.. ill not mention the water pump then.

 

[Nixdorfer]

If there is rubber in there oil and rubber don't mix well. Rubber will swell, see it a lot on cars that come in with oil leaks where hoses are twice the usual size.

If there is any oil residue in the lpg then might explain the swelling. Won't take much to kill it if the tolerances are that small

Article here actually mentions the shutoff type regs.

Practical advice: Fitting a Truma gas filter

Preventing your caravan’s gas system from gumming up by fitting a Truma gas filter

www.outandaboutlive.co.uk

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[andy63]

Article here actually mentions the shutoff type regs.

Yea..they suggest that the residue bungs up the regulator..
Its a mute point but even though the residue is most probably responsible it doesn't bung the regulator up.. It attacks the rubber which ultimately causes failure...
The residue can clearly be seen in one of the photos of the failed regulator I opened up.. There's not a lot of it anyway.
Andy

 

[Nixdorfer]

So bottom line seems to be for the relatively low cost and time it takes its worth fitting a filter

Apart from the cost there aren't really any negatives

 

[Pausim]

My filter has intercepted residue, found quite a puddle in the bottom once, I suspect it saved my regulator.

When I fitted my Autogas refillable I was warned that if there is insufficient fall back in the pipe from the regulator back to the bottle, the residue can be pushed the wrong way i.e. into the regulator rather than running back to the bottle where it belongs. If you are using taller bottles you may find you need to raise the height of the regulator.

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[Basildog]

As all regulators should be installed higher than the cylinder outlet it seems like many people are actually fitting filters to compensate for a badly designed / installed system
Regulator hoses (pigtails should have a continuous rise to the regulator if correctly installed ??