Butane and bulkhead regulator update (1 Viewer)

[timdownieuk]

Some may remember that I had problems with excessive sooting in our fridge chimney and carbon monoxide production from our oven when running on butane.

Well, I checked the regulator pressure today and found that its ouput pressure is 40mbar (as opposed to the 30 it should be doing). I think that's enough to explain our problems.

The present one is a Truma Secumotion one. Should I replace it with the same or are there better ones out there?

Tim

 

[Derbyshire wanderer]

If you are having to replace anyway why not fit a propane regulator as it's output is more stable over a much wider temperature range?

 

[Dorset Diver]

If you are having to replace anyway why not fit a propane regulator as it's output is more stable over a much wider temperature range?

That's a new one on me can you give a more in-depth explanation .

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[Derbyshire wanderer]

Propane doesn't freeze til minus 43C but butane will start to freeze at about 5C so for year round use butane is not suitable

 

[Dorset Diver]

Propane doesn't freeze til minus 43C but butane will start to freeze at about 5C so for year round use butane is not suitable

Agreed, but what has this got to do with a bulkhead regulator?

 

[Derbyshire wanderer]

Agreed, but what has this got to do with a bulkhead regulator?

Not quite sure where you're going with this but I assume that your point is that a bulkhead regulator can have an input hose for either type of bottle?
The regulators although usually have the same 30Mb output the bottle pressures are different as propane is higher and the regulators are therefore different.
Butane through a propane regulator should have no problem but not sensible to put propane through a butane regulator.

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[tonyidle]

I assume you checked the pressure with at least one appliance turned on? You will get an incorrect (higher) reading if not.

 

[Dorset Diver]

Sometime ago the brains in the EU decided that rather than use either a Butane regulator running at 28 psi or a Propane reg running at 37 psi specifically for the respective gases there would be harmonisation to a standard bulkhead regulator running at 30 psi for use with either gas. This also involved the gradual change of new gas using equipment to best accept this compromise pressure. To suggest that the OP should change to a propane (37 psi) regulator would mean feeding his fridge with a pressure to which it is not suited. IMHO his Truma Secumotion reg is clearly faulty and should be replaced with a similar unit that both supplies 30 psi and the secure motion function.

 

[Dorset Diver]

Some may remember that I had problems with excessive sooting in our fridge chimney and carbon monoxide production from our oven when running on butane.

Well, I checked the regulator pressure today and found that its ouput pressure is 40mbar (as opposed to the 30 it should be doing). I think that's enough to explain our problems.

The present one is a Truma Secumotion one. Should I replace it with the same or are there better ones out there?

Tim

Tim, what colour is the flame of fridge gas burner? It should be predominately blue with minimal yellow tips.

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[timdownieuk]

I assume you checked the pressure with at least one appliance turned on? You will get an incorrect (higher) reading if not.

Ah, good point. I had forgotten that. I shall re-check tomorrow.

Having said that, the symptoms do seem to fit with an excessive system pressure.

 

[timdownieuk]

Tim, what colour is the flame of fridge gas burner? It should be predominately blue with minimal yellow tips.

There's no viewing window in my fridge. I think excessive sooting is evidence enough of a problem.

 

[timdownieuk]

Not quite sure where you're going with this but I assume that your point is that a bulkhead regulator can have an input hose for either type of bottle?
The regulators although usually have the same 30Mb output the bottle pressures are different as propane is higher and the regulators are therefore different.
Butane through a propane regulator should have no problem but not sensible to put propane through a butane regulator.

Um, wrong way round. Butane through a traditional 37mbar propane regulator would be supplied at a higher pressure than normal. Through a 30mbar bulkhead regulator it's only being supplied at 1 mbar higher that "normal".

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[Dorset Diver]

There's no viewing window in my fridge. I think excessive sooting is evidence enough of a problem.

Can you not see the flame from the outside with the vent grill removed?

 

[timdownieuk]

Can you not see the flame from the outside with the vent grill removed?

Not really. The base of the flame perhaps but the top is hidden in the chimney. A bit academic though as the soot shows that there *must* be incomplete combustion.

 

[Dorset Diver]

True, but too little air could cause the same problem.

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[Derbyshire wanderer]

Um, wrong way round. Butane through a traditional 37mbar propane regulator would be supplied at a higher pressure than normal. Through a 30mbar bulkhead regulator it's only being supplied at 1 mbar higher that "normal".

You have misread my post.
Modern butane and propane regulators are both 30Mb output but are designed for different gas input pressure.
I had not replied with reference to your existing drive safe unit rather than the type of gas used.
It was @Dorset Diver who then asked the questions about the gas difference even though he already knew the answers and so ended going off topic.
Not a problem though as you both have worked out how to rectify.
Good luck with getting it sorted

 

[Dorset Diver]

@Derbyshire wanderer I think you will find that with bulkhead regulators there is no such thing as Butane or Propane specific units. The harmonisation was aimed at one size fits all. I don't agree with the idea, but that is the situation. Generally speaking it suits the continental market as most of the bottled gas supplied there is a mix of Butane and Propane and the mix is adjusted throughout the year to suit warmer and cooler weather.

 

[2657]

@Derbyshire wanderer Generally speaking it suits the continental market as most of the bottled gas supplied there is a mix of Butane and Propane and the mix is adjusted throughout the year to suit warmer and cooler weather.

Don't think so!....everwhere I have been in Europe both Propane and Butane are the only types of bottled gas apart possibly from some bbq gas.

Autogas varies from country to country but bottled gas is either Propane or Butane, at least that's what it says on the bottles.

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[timdownieuk]

Ah, good point. I had forgotten that. I shall re-check tomorrow.

Having said that, the symptoms do seem to fit with an excessive system pressure.

Okay, I've rechecked it and it's 33 mbar. 3 mbar over spec but this doesn't feel like enough to cause the problems but maybe it is? Thoughts?

 

[Dorset Diver]

@timdownieuk What colour do the gas ring burn?

 

[pappajohn]

Sometime ago the brains in the EU decided that rather than use either a Butane regulator running at 28 psi or a Propane reg running at 37 psi specifically for the respective gases there would be harmonisation to a standard bulkhead regulator running at 30 psi for use with either gas. This also involved the gradual change of new gas using equipment to best accept this compromise pressure. To suggest that the OP should change to a propane (37 psi) regulator would mean feeding his fridge with a pressure to which it is not suited. IMHO his Truma Secumotion reg is clearly faulty and should be replaced with a similar unit that both supplies 30 psi and the secure motion function.

I hope not, you would have a serious fire on your hands.
You mean 28 and 37 millibar don't you !

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[Dorset Diver]

I hope not, you would have a serious fire on your hands.
You mean 28 and 37 millibar don't you !

@pappajohn Well done you spotted the deliberate mistake. No prize sorry .

 

[pappajohn]

@pappajohn Well done you spotted the deliberate mistake. No prize sorry .

But....But...But, I deserve a prize...a very big and expensive prize. Pretty please !

 

[Dorset Diver]

But....But...But, I deserve a prize...a very big and expensive prize. Pretty please !

But did you see the other? A clue "one down".

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[Dorset Diver]

"Mistakes" and "prizes" aside @timdownieuk does seem to have a strange one.

 

[vwalan]

the main thing is what pressures etc are the items designed for . some used to be 50mb
i know my cooker came with a list of what mbr and what jet sizes to use etc .
possibly the fridge involved as a similar sticker or info with it .

 

[timdownieuk]

@timdownieuk What colour do the gas ring burn?

Blue on propane, with some yellow tips on butane.

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[Dorset Diver]

Blue on propane, with some yellow tips on butane.

Not far our then but marginally better on Propane. Perhaps as @vwalan suggests the jetting is wrong or the air supply is not good. The only other thing I can think of is the flow from the regulator. If you turn on all of the appliances do the cooker rings die back or just keep going with little or no change as they should?

 

[timdownieuk]

Not far our then but marginally better on Propane. Perhaps as @vwalan suggests the jetting is wrong or the air supply is not good. The only other thing I can think of is the flow from the regulator. If you turn on all of the appliances do the cooker rings die back or just keep going with little or no change as they should?

I turned all the rings on but the pressure stayed up at 33mbar so clearly the regulator is regulating, just not at the right pressure.

I must admit I rather resent the thought of spending over £80 to get another "crash safe" regulator to achieve a 3mbar drop. Tempted to have a closer look at it to see if there's a "hidden" preset screw or adjustment as in all other respects, it's working fine.

(Before anyone screams, yes I do know that I shouldn't blah, blah blah, but I have more faith in my own ability to leave the system "safe" than a tech guy who doesn't actually sleep in the van. Nothing like having a vested interest to concentrate the mind. )

 

[Dorset Diver]

IMO a 3.0 m/bar discrepancy is not going to cause the problem you are reporting. I think that it would be considered to be within spec but of course only Truma can say for sure. If the cooker and other burners are running well perhaps you should have a look at the fridge burner itself.

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