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Regulating propane

Posted: Wed Oct 10, 2012 5:05 pm
by CS
Both type of regulators I used never stopped venting. My guess is the temperature of the propane is making seals leak because the rubber is shrinking. So do I need a buffering tank to allow the propane to warm in a gaseous state? I did try different angles of tank, that didn't work. What the heck?!

Posted: Wed Oct 10, 2012 5:35 pm
by jrrdw
Are the regulators made for propane or compressed air? Come to think of it, I've never seen ANY propane regulator hold true for a length of time. I never leave the torch on my bottle...

Posted: Wed Oct 10, 2012 10:50 pm
by CS
After some pondering at work I surmised...

The propane changes temperature as it flows through the regulator, that means it passes through the regulator at the correct pressure, then as it lingers downstreams it warms and expands. Is that why it is venting? Suprised I haven't read about this problem...

Jrrdw, they are compressed air regulators.

Posted: Thu Oct 11, 2012 5:22 am
by Lazyboy
I suspect you have Relieving regulators, they do vent when down stream pressure increases, see below.

Relieving & Non-Relieving
Regulators can be a relieving type or non-relieving. The application dictates which you would use.
For example, if you were regulating the pressure of a noxious or expensive gas, you would select a non-relieving regulator to prevent off-gassing of that poisonous gas into the plant atmosphere through the regulator, or the waste of an expensive gas through a relieving regulator.

Most industrial systems use a relieving regulator. With a relieving regulator, if the downstream pressure exceeded the pressure setting on the regulator for any reason, then the higher downstream pressure would be allowed to vent back through the regulator to the atmosphere.

Posted: Thu Oct 11, 2012 7:26 am
by jrrdw
CS wrote:Jrrdw, they are compressed air regulators.
Aren't propane regulators built for much higher pressures? That could be a factor in it. Would gas grill regulators work better?

Posted: Thu Oct 11, 2012 4:17 pm
by natas
regulators usually do not like liquid gas, but you already said you tried different angles.
Have you made sure the gas flow goes the right way trough the regulator ? usually they only work one way, and there is small arrows on the regulator telling wich way the gas should flow.


( just eliminatin the first things first :-)



I use a big sturdy regulator from Festo, it works like a dream, and don't get grumpy if i pour some liquid gas in it now and then :-)

Posted: Thu Oct 11, 2012 10:28 pm
by Technician1002
Gas grill regulators regulate to a very low pressure. They measure the pressure in how high it can lift water in a tube. Typical grill regulators are set to 11 inch water column. This means that the pressure is not high enough to blow bubbles from a tube submerged 12 inches deep. The input pressure is simply the bottle pressure which varies by temperature, or typically 60-200 PSI input.

Torch regulators with a much smaller diaphragm most often are regulated at a much higher pressure of 7-15 PSI.

Info on propane regulators..
http://gashosesandregulators.com/propan ... facts.html
Pressure in a propane tank, large or small, can range between 100 and 200 psi. This propane pressure must be reduced and regulated for use in a home, motor home, camper, or an outdoor gas appliance. Typically, a residential application will require a low pressure regulator which reduces the gas pressure to 6 ounces (10.5 inches water column).
To prevent pressure loss on a long run from a tank to a house, often the tank is regulated with a RED high pressure regulator and then dropped to low pressure at the house for the low pressure stove, water heater, furnace, etc.

Posted: Thu Oct 11, 2012 11:15 pm
by D_Hall
FWIW: I've been extremely pleased with McMaster-Carr part number 4677K61. It's a tad expensive, but that thing rocks. I set it once. I come back to it months later and it's still on the setting I left it. Similarly, I've never detected any significant leakage. I can disconnect the supply, come back the next day and still have within a few psi of the pressure I left it at.

Posted: Mon Nov 26, 2012 1:12 am
by BigGrib
What size bottle are you using? 5 lb or 14 oz? If you're using a 5 lb tank I recommend bayou classic 0-30 adjustable regulators. They have a 1/4 FPT outlet which is a nice thread up to your hose.


http://bayouclassicdepot.com/7850_propane_regulator.htm