Gas Pressure ??

Discussion in 'Tech/Mech General' started by rupert, Jul 18, 2015.

  1. rupert

    rupert Funster

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    anyone out there that can tell me whats happening with gas pressures. I've always believed you need 37 mbar for propane or 28mbar for butane for your appliances to work at there best.
    so whats going on with this fixed gas regulator fitted in my cheyenne that someone has deemed to be 30 mbar (too much for butane, and too little for propane) is this reg supposed to be ok for both gases or can i purchase one at 37 mbar ?
    my fridge stopped working on gas last week .ok on electric, so i cleaned the jet etc.there was no sign of any dirt present, as idid it about a month ago. but now its working again...,great.... but i feel its not working as well as it should.which prompted me to check the gas.
    so.. have the makers allowed for the 20% drop in propane pressure, or do you think it won't make any difference to my fridge? any comments.
     
  2. pappajohn

    pappajohn Funster Life Member

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    30mb is now a standard pressure for both propane and butane.
    to change from one to the other you just need a pigtail to connect to the regulator.

    Some German vans have 50mb regulators fitted.

    Appliance jet size will dictate if it can run at 30mb

    I dont think the pressure is to blame for your fridge fault but next time it happens turn on the hob and heating to see if they work.
     
  3. rupert

    rupert Funster

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    thanks for the response ppj if i need a new jet how do i determine what size jet I've got. the jet thats in there lives at the end of the pipe as it enters the block that lets in the air (maybe called venturi) if you see what i mean. its like a very small war time tin hat with a wee hole in it haha... ps i did try the hob etc.for gas an all was well
     
  4. pappajohn

    pappajohn Funster Life Member

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    Jet packaging should say "suitable for 30mb" or something like that.

    To be honest the difference between 27mb and 30mb really wouldnt be noticeable as far as flame is concerned.
     
  5. rupert

    rupert Funster

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    I'm using propane. so should be 37mbar . am i right, if so thats about 20% drop in pressure. not insignificant
     
  6. tonyidle

    tonyidle Funster

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    Not relevant either. I think you'll find the fridge manufacturer will tell you the same.
     
  7. pappajohn

    pappajohn Funster Life Member

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    If you have a factory fitted 30mb regulator, usually bulkhead mounted, the appliances will have been jetted to suit 30mb.
     
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  8. rupert

    rupert Funster

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    of course that never occurred to me haha.should be.. i may check though with AT. because I'm thinking if the thermostat controls the flame.. less pressure = lower flame= higher temp in fridge
     
    Last edited: Jul 18, 2015
  9. rupert

    rupert Funster

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    i still bet it runs better/ colder on butane @ 30mb... anybody done any experiments on this ?
    it could make fans obsolete......just maybe:unsure:
     
  10. SomeoneElse

    SomeoneElse Funster

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    This is worth a read:
    www.caravanclub.co.uk/media/7832484/ccmseptechnical.pdf
     
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