Globetrotter Posted October 5, 2006 Share Posted October 5, 2006 Hi All When I bought my last van over a year ago (A German import) I noticed stickers saying that the gas system pressure was 50MB. However, because no regulator was provided, I used 37 MB regulators of both types (Butane/Propane) without any problems. Recently picked up our new van, also a German import and also with 50 MB stickers. The dealer gave dire warnings about not using the correct 50 MB regulator, but wasnt specific as to why I should. Does anyone know why, and are 37 MB regulators OK as they were in my last van?? Many thanks! Link to comment Share on other sites More sharing options...
Basil Posted October 5, 2006 Share Posted October 5, 2006 Gas appliances are designed to perform to a given standard. They have a rated output that is determined by the Calorific Value of the gas and the flow rate per hour in cubic metres. A burner is fitted with a specifically fixed size injector that will give that pre determined flow rate at a given pressure, hence the correct heat output (slightly simplified as it actually determines the heat input and the efficiency of the appliance determines a lesser output). Now if you run the appliance at a lesser pressure, this will mean any appliance installed on the system as one regulator determines the pressure over the system as a whole, the heat input will be reduced and as a consequence the heat output will be reduced as will the efficiency of the appliance. This can also lead to poor quality flame picture and hence poor combustion, you would see this as a slack flame possibly with yellow tipping which would be a very undesirable situation. So in a nutshell if you provide the gas to an appliance at a lower pressure than the injectors are sized for you may well get insufficient heat from it, i.e. heating unable to raise the temperature to sufficient levels in colder weather, hob taking longer to heat kettles and hot water not heating very quickly, flame failure devices may not operate correctly, i.e. keep shutting off, or in worst case you may have potentially lethal products of combustion being given off by badly burning flames on your burners. In reality you are looking at a 25% (approx) reduction in working pressure with what you have described and I would guess that you will find reductions in efficiency rather than flame problems, personally I would try to use the correct pressure regulator. Bas P.s. Just noticed that you said you used Butane/ Propane regulators at 37 mb, they are of course different pressures for Butane and Propane not both 37mb, as the have differing CV's the difference in pressure creating the different flow rates to give the correct input/ output. Link to comment Share on other sites More sharing options...
tonyishuk Posted October 5, 2006 Share Posted October 5, 2006 One of those silly thoughts :-D Does this mean that a gas fridge will run hotter if run on the lower pressure ? [ I.e lower pressure means that the fridge is not running at such a heat and the inside temp becomes warmer ?) edit splleing ! Link to comment Share on other sites More sharing options...
Globetrotter Posted October 5, 2006 Author Share Posted October 5, 2006 Thanks-I understand the principle of what you are saying, but never noticed any of those symptoms with my old van. I have been supplied with a 50 MB Propane reg-anyone know if a suitable clip on Calor one is available for butane ? Link to comment Share on other sites More sharing options...
Basil Posted October 6, 2006 Share Posted October 6, 2006 Tony, Re fridge, no quite the contrary, in simple terms the gas fridge relies on the temperature at the 'boiler' part of the unit to boil and vaporise the liquid inside to create the pressure to make the fridge work. Lower pressure could make the appliance inefficient and unable to cool sufficiently in hotter ambient temperatures. John Yes it is quite concievable that you didn't notice anything, that is not to say that had you been using the correct pressure that it would have been better than it was. Had it been me, as a qualified person, looking at your situation I would have checked and tested the appliances to ensure that they were ok, but it would be very wrong of me on this forum to say that there is no problem doing what you are doing having had no first hand view of the system. Likewise if I were in your situation with my own van, I would install a suitable regulator that used standard (to the UK) fitments and if the appliances needed 50mb I would have reset it to that pressure, but that is a job for a qualified person that knows what they are doing. Bas Link to comment Share on other sites More sharing options...
Globetrotter Posted October 6, 2006 Author Share Posted October 6, 2006 Thanks Bas. I think I will stick with the propane then, using this 50 MB regulator I was provided with. Better safe than sorry.... Link to comment Share on other sites More sharing options...
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