OPD valve propane tank problems

[erps]

Has anyone else found that the new propane tanks are kind of finicky? I've had some problems with both my weed burner at home and my BBQ on the boat getting adequate fuel. I did a little googling and found that the new tanks have some sort of a "free flow" safety device as well and you can get full gas flow by not openning the valve all the way up. I'll try it next time I'm BBQing, but just wondering if anyone else has run into this problem?

This webpage talks a little bit about the issue:

http://www.enigmetallic.com/propane.htm

[Faster]

I have noticed something similar to what you describe - if I neglect to close the BBQ burners before opening the tank valve, even with the tank valve open there's no gas flow. I suspect that the "free flow" limiter doesn't like the surge to the open burner and cuts off. If close the tank, shut the burner valves, and reopen the tank it works fine when I light the burners after that.

But I've only noticed this at home on the larger BBQ. On the boat things seem fine.

[peikenberry]

Just try turning on the valve slowly. There are valves in the line that close when there is a surge. Turn it on slow, no surge, no problem. I have had this problem with the propane system om my motorhome. If it happens, turn off the valve at the bottle. wait a minute for the pressure to drop, turn the valve on slowly........

[bushrat]

It's the safety feature of the valve. If there is a leak the excess flow valve will close. It is also designed to not open unless an appliance is attached. The old style valves were very dangerous in that if left on, or if a line leaks, gas just kept flowing. Kids used to crank open them and get LPG in the face and on the hands causing freeze burns. Ensure appliance is connected properly and off, open valve slowly, if not working, wait 5 min. for any gas to clear and for the valve to reset itself and repeat.

[bushrat]

Another source of grief with propane appliances is that new cylinders are not purged properly when filled for the first time to eliminate contaminates and primarily any moisture. Moisture or water will ice up when filled with LPG. Always close the valve on an empty cylinder, especially the old style valves which are still in use. Technically a cylinder should be purged when filled for the first time, revalved or left open when empty. Many times they are not.
You can also get contaminated LPG just like any other fuel. I have heard from others that those bug traps are especially sensitve.

[bushrat]

Another thought. If it is happening only after the cylinder has just been filled, it may be that the cylinder has built up pressure especially if it's in the sun causing the excess flow and the excess flow valve to shut. Partially opening the valve would help. You can also vent some pressure by opening the spit valve. On the opd it is a small set screw on the side. Crack it open in a well ventillated area and let off some pressure. If you see liquid propane, it definately has to much pressure or is overfilled, let it go until it is just vapour. Hope this helps.

[Faster]

Good point on the purging, Bushrat. We are running into a situation nowadays that municipal bylaws prohibit purging of new empty tanks for environmental reasons - and we are forced to buy "pre purged"/prefilled new tanks.

[bushrat]

A lot of the cylinders on the market are refurbished these days. I doubt they take the time to purge when the cylinders are revalved and filled. I see cylinders sitting at the hazerdous waste depot with no valve because the valuable brass has been taken to the scrap metal dealer. The cylinder is picked up for "refurbishing" by the propane company. A shot of paint, new valve, fill, back in service. If you have been having trouble it is llikely a refurbished cylinder. Trade it at a swap and go or buy a new one and make sure the attendent actually purge it. I didn't know that about the bylaw?

[Freesail99]

Has anyone used the composite cylinders ?

http://www.propaneproducts.com/lite-cylinder.html

[sailingdog]

Freesail-

The composite cylinders are great, and you can actually see the level of the propane remaining in them. However, they need to be covered for the same reason... otherwise sunlight can cause them to heat up a lot...greenhouse effect of the somewhat clear sides...