The suspected gas bottle explosion that killed a father and his kids at Timbertops Caravan Park in Mandurah, W.A. had me thinking yesterday.
Just a few months ago I bought one of those "Gasfuse Safety Gauge's" that go on the gas bottle. Yesterday thinking about that incident, I tested the gas bottle valve to make sure they were off.
The Gasfuse gauge on the bottle reminded me of a simple test we used to carry out on gas lines we had just installed. This was in factories for boilers or gas fired process equipment/machinery. Usually 50 to 100 mm dia pipe. And is still used by plumbers for line testing.
We closed all the outlet on the system. Then filled the system with compressed air at a pressure of 35 Kpa (about 5 psi) monitored with a pressure gauge. Closed the compressed air inlet and left the sytem with pressure in it for a few hours, even overnight. If the pressure had hardly dropped we did not have to go looking for leaks, with soapy water and a brush. The gas inspector did the same test.
So yesterday I realised I could do this with the "Gasfuse Gauge".
To Test Your System
Ensure all your gas appliaces are OFF. Fridge, cooker, heaters etc.
This means pilot flames off as well.
OPEN the gas bottle valve and activate the gasfuse, by pessing the gauge down once. This will pressurise the lines/system with gas, and the gauge needle will show the pressure in the yellow or green .
(Be a good thing to test every time a fresh bottle is put on, also after driving for hours over corrugated roads).
CLOSE the gas bottle valve, and observe the needle on the gauge for say two or three minutes.
If the pressure gauge needle drops you possibly might have a gas leak. Get a licenced gas fitter to loook at it.
If it remains steady and hold pressure the system can be assumed to be secure.
I also checked the gauge after about an hour and it was still in the same place. But on such a small systems as caravans or motorhomes 2 or 3 minutes would give some indication.
You should get a yearly maintenance gas check done as well.
Regards
Mike
-- Edited by elliemike on Friday 6th of May 2011 06:25:35 AM
-- Edited by elliemike on Friday 6th of May 2011 06:26:03 AM
-- Edited by elliemike on Friday 6th of May 2011 06:27:12 AM
-- Edited by elliemike on Friday 6th of May 2011 06:27:51 AM
-- Edited by elliemike on Friday 6th of May 2011 12:01:21 PM
-- Edited by elliemike on Friday 6th of May 2011 01:47:19 PM
What about the simple and effective soap/Water trick....I always coat the the connections with a brush of soap/Water.....Have only once found my connection to be loose that was 20 years ago....Still thanks for that advise
__________________
I always leave my camping area cleaner than I found it.
I have a gauge on my gas bottle, but I thought it was only for seeing how much was in the bottle, is this a differant gauge to the one you are talking about?
What about the simple and effective soap/Water trick....I always coat the the connections with a brush of soap/Water.....Have only once found my connection to be loose that was 20 years ago....Still thanks for that advise
Yep Jimbo
Still a good test method of course. I actualy did use soapy water test recently as I had my Fridge and Cooktop out so I could get at sommat else. There are three or four compression fittings on my setup that are only acessible with these units out. Also pretty tight under my van to get at the valve fittings there. Use whatever test suits the situation.
Different Ships Different Long Splices, as me dad used to say
We have been using the pressure gauge sold as "gasfuse" (http://gasfuse.com/) for the safety cut out aspect for many years, plus as a check that the gas lines have not been compromised (as per Mike & Ellies post) by flying stones etc. We have them on both external 9kg bottles on the van and on our BBQ bottle at home. We use the soap and water method whenever we have to reconnect the gas bottles.
We also find that "gasfuse" does give quite a reasonable indication as to the amount of gas in our bottle. After a while you can certainly see the needle in the gauge slowly dropping as you use the gas. Ambient temperature and direct sunlight on the gas bottle does effect the gauge readings and must be taken into account. You need to go through a couple of bottle refills to get a good idea as to what the gauge is telling you with respect to your normal gas usage. Then when the gauge finally hits the red section you will know how much longer you have with your normal gas usage or that its time to quickly ready the second bottle.
is there one that tells you how much is in the tank?
Happywanderer posted this tip a little while ago.
Boil the jug and pour over the gas bottle. The empty bit will be really hot under your hand when you touch it, the full bit will be quite cold. There is really a surprising difference.
There are some adhesive backed strips available that you stick on the bottle and work much the same way as the method suggested by HW and Sheba. You pour hot water over the cylinder to activate it. I think just feeling the bottle as suggested works just as well.
I once had a cylinder that had a quantity gauge in it that "worked" by using a float, similar to a fuel or water tank gauge. In actual fact it didn't work very well at all so I guess that's why they're no longer around.
Propane (the main gas in the cylinder) is actually a liquid while it's under pressure and this is what you're measuring when you feel the temperature of the bottle. The gas (vapour) on top of the liquid maintains a constant pressure of about 480 psi (Techies know this as the "critical pressure") so using a pressure gauge to measure the quantity doesn't work.
Another way to tell is to weigh the cylinder. The tare (empty) weight and full weights are stamped on the side of the bottle.
I have two cylinders on my rig so I just wait until one is empty then cut over to the other.
The gas (vapour) on top of the liquid maintains a constant pressure of about 480 psi (Techies know this as the "critical pressure") so using a pressure gauge to measure the quantity doesn't work.
Agreed that the "gasfuse" pressure gauge will not tell you that your bottle is 3/4,1/2, 1/4 full but it does with experience give you a good guide as to when you need to be prepared for the bottle to run out.
The "gasfuse" has four zones marked on the gauge. Red (refill), green (gas), hatched white (high) and then a large yellow zone. When we connect up a full bottle, in say mid 20C temperature, the "gasfuse" needle usually shows towards the top of the "high zone". If the bottle is left in the direct hot sunlight the needle over time will drift up well into the yellow zone. In very cold weather it will tend to drift toward the "green zone".
The needle will remain relatively constant for quite a long while but eventually after quite a deal of gas use the needle will drift down into the "green zone". Our BBQ bottle the needle at present is sitting in the middle of the "green zone". After a couple of more uses that needle will be down to the edge of the "red zone" maybe even into the "red zone". Time to get the spare bottle ready, or on the van be ready to swap over to the second bottle, particularly if you are cooking a roast for a couple of hours as the gas will run out very soon.
-- Edited by Ron and Shirley on Saturday 7th of May 2011 10:57:53 AM
I thought you cooked the roast in the camp oven beside the campfire???
At home we have had a Webber Q since they first appeared on the market and all our roasts since have been done outside on the Q.
In the bush we use to use the camp oven, then we moved to a Cobb cooker, but since getting the Caravan I am afraid the Webber Baby Q on the van tends to be the method of choice nowadays.
Convenience I guess, plus never had a failure with the Webbers, so our campfires nowadays are mainly for happy hours, warmth, and .boiling the billy.