Propane Tank Question
Is this true? ""Propane tanks have a safety valve that shuts if a gas line should break and allow full flow.""
Forum Discussion
I hope you are not understanding what I am talking about, because everything I said is 100% accurate- let me try to make you understand..
The check valve and the orifice in the valve are 2 different things, the check valve keeps LP from flowing if nothing is hooked to the valve- the ACME pigtails have low temp melting parts, so the pigtail will back out in a fire, shutting off the flow. We are not talking about that.
The orifice is just that- it does nothing to stop the flow, it simply limits it. If an orifice is freezing, the cylinder has been over filled, and is under liquid. It is not meant to shut anything off.
I just went out and hooked my full flow pigtail to my OPD equipped cylinder, and I got full, ~150 psi LP vapor for the 10 seconds I left it open- that's a lot of LP. Nothing stopped the flow or "froze". I can post a video if you wish.
Yep- because the pigtail has the excess flow valve in it.
parkmanaa wrote:
You are terribly wrong, Chris Bryant.
The "pigtail", when screwed into the OPD POL fitting, releases the check valve and allows normal flow of propane, but if you open it too quickly it will freeze the tiny orfice. You can open it very slowly and bring it to full flow, but again, as with a line failure, if it is a sudden burst of propane flow, it will freeze up.The "pigtail", or longer line, if you wish, has nothing to do with the safety features built into the OPD valves.
The check valve and the orifice in the valve are 2 different things, the check valve keeps LP from flowing if nothing is hooked to the valve- the ACME pigtails have low temp melting parts, so the pigtail will back out in a fire, shutting off the flow. We are not talking about that.
The orifice is just that- it does nothing to stop the flow, it simply limits it. If an orifice is freezing, the cylinder has been over filled, and is under liquid. It is not meant to shut anything off.
I just went out and hooked my full flow pigtail to my OPD equipped cylinder, and I got full, ~150 psi LP vapor for the 10 seconds I left it open- that's a lot of LP. Nothing stopped the flow or "froze". I can post a video if you wish.
I happen to own a propane dispensing station, and about the only time we screw a pigtail in the POL valve is to purge a new cylinder, and many times have opened the OPD valve too quickly and had the flow shut off immediately.
Yep- because the pigtail has the excess flow valve in it.
