Easy. First, understand what you are testing for. Leaks in the pipework.
So the first thing to do is to turn off all the appliances that use gas. A pilot light or a burner running low looks like a leak!
Then you need to find the leak test point. The regulator may have one: they look a bit like a grease nipple. If you can't find it anywhere, you may need to add one. Basically it is a connector that you can attach a pipe to, with a tap or screw in plug to stop it letting gas out when not in use.
Then you get your length of clear flexible pipe and half fill it with water. The idea is that the water sits in the bottom of a U shape. You need three or four feet of pipe with the water rising about 9 inches either side of the U bottom. A bit of ink in the water may make it easier to see. A felt tip to mark the level may also be handy.
Open the test port and secure the pipe nicely and securely in place on it. (getting this right is the tricky bit: probably easiest to tape the U section of the pipe to a vertical bit of wood).
The water will rise about six inches at the open end and fall the same distance at the gas end. The difference in height tells you the pressure. Your system pressure varies according to when the van was built and (perhaps) what sort of gas you are using. You are not checking the precise pressure here: just checking for leaks.
Now turn the gas supply off at the cylinder or the tank. The water in the pipe should not fall more than a tiny bit. If it does, there is a leak. You may be able to work out where any leak is by turning off the valves that distribute gas to the different appliances and re-running the test.
If the water doesn't fall, give it a little while, just in case there is a very slow leak. You could have a coffee now, if you had remembered to boil the kettle before you started!
Supposedly there is a permitted amount of leakage. If I detected any leakage, I'd get it sorted.
If there is no sign of the pressure falling, it is just possible that the gas valve you turned off is leaking. To check this, leaving the pipe in place, turn a burner on on the cooker to let the pressure out of the pipes, then turn it off again. The water in the pipe should have levelled out when you turned the burner on, and not rise again after you turned it on again. If it does rise at this point, the gas wasn't properly turned off, so the leak test was invalid. Get it sorted.
[note] Do this test last (not first), otherwise you may be putting cold gas into warm pipes which would make the test take longer.
Apparently, I need to tell everyone that afterwards you need to check that you have closed the test port and that it is not leaking. Please don't feel insulted by me stating the bleeding obvious. Check it isn't leaking by spraying with leak testing spray, or squirting it with a mixture of washing up liquid and water, or smear it with some child's bubble stuff. There should be no bubbles blown.
Last edited by hairydog; 12-12-2017 at 14:44. Reason: Added a check for leaking gas valve and TP
Last edited by Alf; 08-12-2017 at 16:05.
1. Turn everything off, leaving the gas supply on.
2. Turn the gas supply off.
3. Turn on a gas burner on the cooker and listen for the sound or smell of gas escaping for a short time.
4. Turn the burner off, turn the gas supply on again, then off again.
5. Go back the next day and turn on the same gas burner on the cooker as before. If you can hear/smell gas coming out like in Step 3, there is no leak.
Thanks all. I live oop north in Durham so if anyone knows a good mobile technician let me know. The fella who fixes my car is going to do a full service each year on the mechanicals as I'm to lazy to do it myself even though I used to strip big diesel engines down. Getting old!
The question is by how much ? please share, Also tell us about stabilisation periods and how if the pressure rises in your contraption whats happening ? is the regulator letting by ? or if it is a warm day is gas expanding in the pipe ? I vouched I wouldn't reply to your comments but this is so wrong and misleading.
The only other gas engineer I know on here is Charlie, I will let him comment as to whether I am being harsh or scathing of your half baked techniques
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