lpg regulator vent specs

For those of you that might be interested, I inquired of Camco about the low pressure "vent". Following is their reply which says nothing about a diaphragm leak -- thus indicating that an excess pressure in the low pressure line would open the vent:

Thank you for your email. I am assuming you are asking at what pressure does the relief valve open on the second stage; if that is what you are asking, it is designed to open at 2-psig.

The overall specifications for this regulator are:

Factory Set Point:
Inlet Pressure: 100-psig

Outlet Flow: 30-scfh (~70,000 Btu/hr)
Outlet Pressure: 11”wc

Flow Capacity: 160,000 Btu/hr @ 25-psig inlet pressure and 9”w.c. outlet pressure

First Stage:
Max Inlet Pressure is 250-psig

Max Outlet Pressure is 15-psig (nominal 10-psi)
Second Stage:
Max Outlet Pressure is 16”w.c. (11”w.c. nominal factory setting)
Has a Type II relief valve to limit the outlet pressure to 2-psig

This could, I would believe, be caused by 1) a defective secondary diaphragm 2) although highly unlikely to get to 2 psi, a build up of pressure due to other causes which are hard to envision and 3) a defective vent which might open below or above the 2 psi spec.

My reason for going to this subject was to analyze if the sudden drop in line pressure to zero might possibly be a result of the low pressure vent. My conclusion is that this vent is not likely a source of the drop.

jdr37 wrote:
Thanks to all.
I will do the procedures as suggested and see what happens.
Yes, my gauge is mounted in the kitchen sink cabinet . I have never "bleed" of the line pressure after turning the gas OFF. I will definitely try this test. I now realize the high pressure between the OFF valve and the regulator, even though seemingly nebulous, may be the reason the pressure stays up for quite some time before suddenly dropping.
I have a feeling the "leak" is likely inconsequential, but, with my "need to know" I will pursue the answer. I'm an old retired fart with too much time on my hands (so my wife keeps telling me) and hopefully can gain a little more knowledge of my favorite toy.
Again, thanks to all.
Dave

You bleed it off to not have to wait for a small leak that may take several hours to show up. Doug

Thanks to all.
I will do the procedures as suggested and see what happens.
Yes, my gauge is mounted in the kitchen sink cabinet . I have never "bleed" of the line pressure after turning the gas OFF. I will definitely try this test. I now realize the high pressure between the OFF valve and the regulator, even though seemingly nebulous, may be the reason the pressure stays up for quite some time before suddenly dropping.
I have a feeling the "leak" is likely inconsequential, but, with my "need to know" I will pursue the answer. I'm an old retired fart with too much time on my hands (so my wife keeps telling me) and hopefully can gain a little more knowledge of my favorite toy.
Again, thanks to all.
Dave

dougrainer wrote:
The odds are the Water heater gas valve leaks especially if you have DSI ignition. Common on older water heaters(more than 10 years old). You have the kitchen sink area mounted LP monometer? What you need to do is this. Pressure up the system, then shut off at the tank, then open a stove range valve and watch the LP needle. When the needle starts to drop, turn the range valve OFF and then watch the needle for 20 minutes. If it then drops slowly or quickly, you have a leak that needs found and fixed. The reason you open the range valve is to remove the slightly higher pressure volume in the lines. Doug

I agree on running the test. That's the way my dealer friend does it.

The odds are the Water heater gas valve leaks especially if you have DSI ignition. Common on older water heaters(more than 10 years old). You have the kitchen sink area mounted LP monometer? What you need to do is this. Pressure up the system, then shut off at the tank, then open a stove range valve and watch the LP needle. When the needle starts to drop, turn the range valve OFF and then watch the needle for 20 minutes. If it then drops slowly or quickly, you have a leak that needs found and fixed. The reason you open the range valve is to remove the slightly higher pressure volume in the lines. Doug

You have a slight leak in the propane system. The reason the gauge drops off all of a sudden is that the high pressure in the two pigtails is feeding the regulator. When that reaches the reg cutoff point the pressure is gone. The only real way to find is to cap all appliances and verify the trailer gas lines themselves. If all is good reconnect one at a time. If you use dish soap as a leak check wash it off any copper or brass when done as it corrodes them.
Just as a shot in the dark, does your oven have a pilot setting on the control. And is it off?
Art.

Every trailer I have had had a slow drain off of the low pressure over time. No valve or connection is perfectly leak proof. I don't think it is a big issue.

Well........

You have a gas valve on water heater, a gas valve on fridge, a gas valve on furnace, a gas valve on stove/oven, numerous fittings/connections........all of them can leak.

It's not uncommon to have to 'purge' the propane system after tank/cylinders have been valved out for a while.
It only has roughly 0.4 psi in system (11"WC). Not a lot of pressure.

In every rv I've owned....I've lit off stove top burners first after valving in propane. To get propane flowing and to place demand on regulator.
This helps when lighting off furnace, water heater, fridge

Some folks call it purging/getting the air out...I prefer establishing flow/demand.

0.4# dropping to Zero a couple days or more after propane valved out......personally I would not be concerned or waste my time hunting for the 'leak'

Thanks Old-Biscuit.
As you can tell I have very limited knowledge of lpg systems. My question was asked because I have a situation I don't understand and am trying to figure out. So far, I have not been able to get even a hint of what is going on in my '95 Cruise Aire.

I replaced the regulator because it was obviously leaking, out the vent I suspect. After getting into the subject I now realize it should have been replaced years earlier!!

The situation is this. After replacing the regulator the line pressure (my unit has a line pressure gauge inside, mounted in the cabinet under the kitchen sink) would read 11", then after shutting the gas OFF the pressure remains at 11" for a day or two then inexplicably go to zero. I suspected the water heater valve may be the cause, disconnected it and capped the line and it seemed to improve but is now doing the same thing but it seems to be a day or two more before it goes to zero.

Thus I thought, well maybe with our warm weather here in Florida the vent is blowing when the line pressure goes up a couple of inches due to the heat. From your reply that is not possibly the problem, so I remain confounded. Do I have a problem somewhere that can/should be fixed or should I just not worry 'bout it???

Any thoughts anyone??

Thanks

Nothing should come out of vents unless diaphragms leak.
Vents (small hole on high pressure side/larger hole with screen on low pressure side) are on the spring side of diaphragms open to atmosphere

1st stage drops cylinder/tank pressure to 15# and 2nd stage drops the 15# down to 11" WC (~0.4#)