Got bit by the LP Regulator check valve!

[5picker]

Had a LP regulator check valve stick on me not allowing much gas flow.
It would hardly allow enough gas flow for one burner on the stove, let alone three!

I first thought it was the red regulator but swapping that out made no difference. I've removed the check plunger and spring for now and everything works great.

Anyone found a source for these separately or is it a total regulator replacement for such a 10¢ item.

It is the brass colored item on each side.

[BriaBeck]

Sounds like you fixed it for free...


Just my opinion... another one of those "safety devices" that causes way more problems than they prevent. I HATE those things!

[5picker]

Originally Posted by BriaBeck

Sounds like you fixed it for free...


Just my opinion... another one of those "safety devices" that causes way more problems than they prevent. I HATE those things!

Well I temporarily got it working... fixed is debatable I suppose.

Don't these checks keep the full tank from flowing to the empty tank when the switch over occurs or do I understand the system incorrectly?

[BriaBeck]

No, they are a "safety" feature. If they "sense" that the rate of propane flow is too high, they shut off and stop the flow. So what happened is when your regulator switched to the full tank, the "safety valve" sensed that the flow was too high, and shut off your propane. They are installed on all kinds of propane burning appliances.


Which I guess, does make it safer, theoretically, at the expense of you not being able to burn any propane, at least until you can get them to reset themselves.


A wonderful invention... Like I said earlier, in my opinion, you fixed it for free. The level of risk you assume is up to you... for me they are way too much hassle for the benefit they provide... provided they would even work when you really needed them to.

[5picker]

Originally Posted by BriaBeck

No, they are a "safety" feature. If they "sense" that the rate of propane flow is too high, they shut off and stop the flow. So what happened is when your regulator switched to the full tank, the "safety valve" sensed that the flow was too high, and shut off your propane. They are installed on all kinds of propane burning appliances.


Which I guess, does make it safer, theoretically, at the expense of you not being able to burn any propane, at least until you can get them to reset themselves.


A wonderful invention... Like I said earlier, in my opinion, you fixed it for free. The level of risk you assume is up to you... for me they are way too much hassle for the benefit they provide... provided they would even work when you really needed them to.

I think we are talking about two different things here.
These are not full flow safety valves such as those built into the tank valve.

These are check valves that when working, allow full flow in the direction the LP flows (opposite of what you said) and do not allow any flow backwards towards the tank.

[Bama Rambler]

You can buy just the ¼" NPT to inverted flare with check valve fitting.

Here's one. ¼" NPT to inverted flare with check valve adapter

[5picker]

Originally Posted by Bama Rambler

You can buy just the ¼" NPT to inverted flare with check valve fitting.

Here's one. ¼" NPT to inverted flare with check valve adapter

Perfect... thanks Bama!

[Herk7769]

Originally Posted by 5picker

Well I temporarily got it working... fixed is debatable I suppose.

Don't these checks keep the full tank from flowing to the empty tank when the switch over occurs or do I understand the system incorrectly?

Those check valves are part of the automatic switch over so you can leave the propane flowing from the good tank, while removing the dead one to get refilled without leaking gas.

Buy a new regulator, they are not all that expensive.

https://www.amazon.com/Fairview-Prop...y&sr=8-1-spell

[5picker]

Originally Posted by Herk7769

Those check valves are part of the automatic switch over so you can leave the propane flowing from the good tank, while removing the dead one to get refilled without leaking gas.

Buy a new regulator, they are not all that expensive.

https://www.amazon.com/Fairview-Prop...y&sr=8-1-spell

Thanks Lou, my assumptions were correct.

I found the check for $5 so I'll invest that before I replace the entire regulator. Should be here Tuesday.

[dalford]

Originally Posted by 5picker

Thanks Lou, my assumptions were correct.

I found the check for $5 so I'll invest that before I replace the entire regulator. Should be here Tuesday.

Where did you find the check for $5? Obviously not Amazon ..lol

[Herk7769]

Make sure you use the yellow Teflon tape made for propane.

https://www.thebbqdepot.com/yellow-g...hoCzpIQAvD_BwE

Teflon tape It is not for use on flare fittings however.

[BriaBeck]

Sorry, I was under the assumption that the regulator handled the anti backflow function... how else could it only draw propane from one tank when they are both full and the tank valves are both open? It has to isolate the tank not being used.

Never have seen a propane tank with a built in high flow safety shutoff.. Not saying that they don't exist, I've just never seen any.

[Herk7769]

Originally Posted by BriaBeck

Sorry, I was under the assumption that the regulator handled the anti backflow function... how else could it only draw propane from one tank when they are both full and the tank valves are both open? It has to isolate the tank not being used.

Never have seen a propane tank with a built in high flow safety shutoff.. Not saying that they don't exist, I've just never seen any.

The selector lever. Both tanks are open, but the check valves and the selector valve in the regulator limit the dispense to the "primary" tank and block the flow to the "secondary" (not selected) tank. When the pressure in the primary drops below the secondary, the check valves move blocking the "primary" (selected) and opening the secondary (non selected) tank.

That is why you must move the selector to the tank supplying pressure before you remove the empty tank from the system.

The OPD safety valves in the propane tank have a high flow shutoff that blocks propane flow if the rubber hose is severed or burned through with the valve open. Some tank valves are so sensitive that rapidly opening them can stop the flow. The system will show green until you place a demand on the system, like opening a range burner. Then it immediately goes red.

You can easily live with this by closing the valves and waiting about 5 minutes for the valve to reset. SLOWLY crack the valve open one tank at a time, taking a second or two between degrees of opening for the first quarter turn. This will allow the hoses and regulator to pressurize without tripping the sensitive safety valve.

Understanding Propane Bottle Valves - Troubleshooting LP Gas Cylinder Connections

[BriaBeck]

Herk,

That article says absolutely nothing about the high flow shutoff valve being an integral part of the OPD cylinder valves. In fact, it states that if the cylinder is tipped or inverted, liquid propane will continue to flow out of the valve. That is certainly a condition that would trigger the high flow shutoff valves to close. Each and every high flow shutoff I have ever seen has been in the appliance supply hose.

I have the same automatic switchover regulator as shown in post 1. About the only thing that i can tell that the selector lever does is reset the red/green indicator so that it will show green on the full tank. All the valve switching and changeover is done by pressure from the full tank. If there is no pressure in the regulator, ie both tanks off and pressure bled off, The first tank that is opened will be the first tank that is drained regardless of the selector position. The indicator will just show red until you turn it to match the tank being drawn from. Play around with it and see for yourself. Maybe others are different, but that is the way the one shown operates.

[dalford]

Originally Posted by BriaBeck

Herk,

That article says absolutely nothing about the high flow shutoff valve being an integral part of the OPD cylinder valves. In fact, it states that if the cylinder is tipped or inverted, liquid propane will continue to flow out of the valve. That is certainly a condition that would trigger the high flow shutoff valves to close. Each and every high flow shutoff I have ever seen has been in the appliance supply hose.

I have the same automatic switchover regulator as shown in post 1. About the only thing that i can tell that the selector lever does is reset the red/green indicator so that it will show green on the full tank. All the valve switching and changeover is done by pressure from the full tank. If there is no pressure in the regulator, ie both tanks off and pressure bled off, The first tank that is opened will be the first tank that is drained regardless of the selector position. The indicator will just show red until you turn it to match the tank being drawn from. Play around with it and see for yourself. Maybe others are different, but that is the way the one shown operates.

Do a test. Take a propane tank without it being connected to anything open the valve fully open. No gas will come out. At least that is my experience.

[dalford]

So, I learned something. This thread got me to do a little research and I found out the reason no gas comes out when the valve is turned on without a connection has nothing to do with anything in the tank. It is part of the OPD valve that requires a hose to be connected to push a plunger that is recessed in the valve assembly.

Check out this video about OPD valves and toward the end it discusses the plunger. I have assumed, incorrectly, that if my propane line was cut or damaged that the gas would not come out due to some safety valve in the tank. That does not appear to be true.

I know sometimes if you open the valve to quickly that gas will not flow. That may be due to the check valves in the switchover system... I don’t know.

https://youtu.be/f1xQMOpHEfw

[Herk7769]

The answer is here:

Understanding Propane Bottle Valves - Troubleshooting LP Gas Cylinder Connections

https://www.youtube.com/watch?v=Y56_...feature=relmfu

https://www.youtube.com/watch?v=A2mBW-McJCI

The high flow shutoff is in the green Pigtail connector not the tank.

Happy Camping!

[nomad297]

Originally Posted by Herk7769

The high flow shutoff is in the green Pigtail connector not the tank.

Correct. It is that simple.

Bruce

[5picker]

Originally Posted by dalford

So, I learned something. This thread got me to do a little research and I found out the reason no gas comes out when the valve is turned on without a connection has nothing to do with anything in the tank. It is part of the OPD valve that requires a hose to be connected to push a plunger that is recessed in the valve assembly.

Check out this video about OPD valves and toward the end it discusses the plunger. I have assumed, incorrectly, that if my propane line was cut or damaged that the gas would not come out due to some safety valve in the tank. That does not appear to be true.

I know sometimes if you open the valve to quickly that gas will not flow. That may be due to the check valves in the switchover system... I don’t know.

https://youtu.be/f1xQMOpHEfw

The stoppage of flow is actually caused by a device inside the big green nut.
It has TWO protection devices built into it.

One... you sorta touched on and that is the plunger that pushes open the recessed valve in the OPD. (on the tank) There is a thermal sensitive bushing inside the green nut which will melt at about +-240º. When the bushing melts, (due to a fire) the plunger springs back and closes the valve in the OPD (on the tank) even if the service valve is in the open position.

The second safety device in the big green nut is the "flow-limiting-device."
Every time the cylinder valve is opened, a small ball in the center of the brass nipple (inside the green nut) is pushed forward into a brass seat. This seat doesn’t totally shut off the gas.

By design, it allows a small amount of gas (by-pass flow) to go into the RV’s gas system. If everything in the gas system is closed and in the off position AND if there are no leaks, the by-pass flow builds up a back pressure that equalizes the pressure which then allows unrestricted flow through the system.

If the cylinder valve is opened when the propane lines are completely empty or there is a severed line, the ball can't equalize and the system shuts down. The by-pass flow will not equalize until some propane gets into the system or a leak is found and fixed.

To rectify, turn the valve off at the tank, make sure everything is closed and at the off position, wait about 15 seconds. If the system is closed and tight, (no leaks, nothing left on) the back pressure builds up, equalizes the pressure and feeds unrestricted gas flow for normal operation.

[Bytesponge]

Originally Posted by Herk7769

Make sure you use the yellow Teflon tape made for propane.

https://www.thebbqdepot.com/yellow-g...hoCzpIQAvD_BwE

Teflon tape It is not for use on flare fittings however.

The yellow tape or sealant designed for Gas lines can be used on the threaded portion of the flare fitting but not required on the flare which is designed to be self-sealing. Probably over kill but will not affect sealing as long as the sealant or tape doesn't obstruct I.D. of plumbing and plug regulator or orifices further down the line.
IMHO