"pulsing" in gas flame

[pophops]

I have noticed a "pulsing" in the flame of the hob when lit. This has been there for some time but it seems to be getting worse gradually. Someone told me today that it could be due to a liquid residue from the propane being present in the pipe. Does anyone know anything about this and what can be done to cure it?

[RLWP]

It could be the gas regulator

 

Richard

[Keeping Up]

I agree it could very well be a build-up of fluid in the pipe. It's happened to us a couple of times with exactly the same symptom, I was told it's the "stenching agent" which is added to the gas to make it smell. The liquid collects at the lowest point - on ours it's where the pipe comes out of the bottom of the changeover valve and makes like a u-bend to get back up to gunwale height before entering the boat through a bulkhead fitting. The cure was simple both times, I just unscrewed the fitting at each end of that short section of pipe then removed it and shook out the oily liquid.

 

The second time (last year) I left it to get too bad and the liquid also got into the control box of the central heating boiler which is the first appliance inside the boat, so that the control valves got bunged up and the control unit had to be professionally repaired.

[Chewbacka]

How old is the regulator? I think they should be changed at 10 years old.

Have you checked the pressure after the regulator?

[blackrose]

It's not just a dirty hob or blocked jets is it? Have you taken the flame spreaders off (when cold) and cleaned under them?

[MtB]

It could be the gas regulator

 

Richard

 

 

Could also just be the flame laughing at the OP...

 

But seriously, it will be goo in the pipe as Keeping Up says. It is of similar consistency to single cream and I'd say there is enough of it in there to be sloshing about.

 

Disconnect the pipework both ends and blast it through with an air line, being careful to catch the eggcupful of goo that will spray out the end!

[DHutch]

I am not an expert, but our regulator once failed the BSS on failing to given enough pressure, and had to the be changed. I am glad we have the BSS for this reason alone.

 

How likely they are to fail in a way which produces and unstable flame I am not sure. In the past I have knows of regulators to hum, sometimes quite loudly, but this has been around the 150-200hz sort of range, which I doubt you would see in a flame.

 

Let us know what you find!

 

 

Daniel

[pophops]

How old is the regulator? I think they should be changed at 10 years old.

Have you checked the pressure after the regulator?

 

I doubt it's the regulator. It was changed along with the flexible hoses last year for the BSS and this problem was noticeable before that. I think I'll try the advice to clear the pipe with an air line as soon as I get the opportunity. Thanks for all replies and I'll let you know what I find.

[system 4-50]

As I understand it, the high pressure pipes into the changeover/regulator from the bottle should be configured to drain back into the cylinder to minimise the chances of this fluid in the pipes. This is often hard to achieve as it requires more headroom above the bottle neck.

Am I imagining this?

Which way do the pipes fall in the OP's case?

[pophops]

As I understand it, the high pressure pipes into the changeover/regulator from the bottle should be configured to drain back into the cylinder to minimise the chances of this fluid in the pipes. This is often hard to achieve as it requires more headroom above the bottle neck.

Am I imagining this?

Which way do the pipes fall in the OP's case?

 

There is a slight U bend but nothing drained from the old hoses when they were changed.

Have yet to investigate other possible low points. We're off for a short break now so it will have to wait.

[system 4-50]

This contains a good account of the problem:

http://www.caravanclub.co.uk/media/1022892/liquefied-petroleum-gas-mo.pdf

[MtB]

This contains a good account of the problem:

http://www.caravanclub.co.uk/media/1022892/liquefied-petroleum-gas-mo.pdf

 

 

Scroll through to page 8 to find it...