Propane Safety - Gas Stop Valve

LewisB · 08-05-2020, 04:17 PM

In a recent thread entitled "Fire Safety", the thread drifted to the subject of Propane Safety and then sort of fizzled out. Thinking specifically about the on-board propane supply for your RV:

It is my understanding that the OPD valve (overflow protection valve) on every propane tank not only limits filling of the tank but also protects the tank when there is nothing connected to the valve. With nothing connected, you can open the tank valve and there will be no escape of propane gas. However, once you connect a hose to the valve, the OPD valve is opened.
Modern connection hoses in use also include an excess flow restriction valve that will limit the flow of gas to about 20% of full open. It is for this reason, the tank valve needs to be opened slowly to allow back pressure to build and prevent the excess flow valve from closing.
If something accidentally opens your system to the atmosphere (accident, broken line from tire blow out, etc.), it would be quite possible to completely drain the tanks at a rate of about 20% of full flow.
There is a valve on the market designed to fully close the propane system at the bottle for any event that allows excess flow rates generated by an open system. If propane flow reaches or exceeds normal values (about 57000 BTU or roughly the equivalent of turning everything in your RV on), the "GasStop" propane valves close at the botttle and stop the escape of propane. This might be a very good investment to prevent bulk loss of propane during an accidental event.

For a much better explanation:

https://www.youtube.com/watch?v=_g38JponlN4

My questions; has anyone used the GasStop valve on their RV? Any comments or suggestions?
Thanks,

**sourdough** · 08-05-2020, 04:30 PM

Thanks Lewis. I would just make folks aware that there are other devices that look almost identical to this one that do NOT cut off the propane. Saw a lady running across the park hollering one day after a guy had left his trailer. Went out to see what the deal was and his propane tank was spewing LP around the connection. I turned the tank off and when the owner arrived later he said it was those "cheap LP gauges" he bought....but they looked just like the one in the video. My thought is to make sure it is the GasStop brand.

LewisB · 08-20-2020, 05:33 AM

Thanks for the response Danny.

After more than 2 weeks, I can't believe there aren't others in the forum that are willing to discuss this subject...surprising...

Brad

**flybouy** · 08-20-2020, 05:59 AM

Brad, I think you may be expecting comments on a product that likely no one owns, nor sees a need for. It may be a great device but I don't think it's that popular, at least not yet.

LewisB · 08-20-2020, 06:14 AM

Thanks Marshall - I think that's exactly right.

In my own case, I was a little shocked when I realized that there was no "safety shutoff" for the propane system with a full pipe failure. We've been camping literally for more than 50 years, starting from tents on a motorcycle to our current Taj Mahal. And we've never had a problem or realized the potential for the problem. So, maybe there is no need for a "fix".

I thought there might be some discussion along that line - when 25-50 forum members respond with "that's a totally unnecessary dumb idea", that kind of answers my question (ha-ha)! I went ahead and purchased two of these and have them in operation. $160 is pricey, but the alternative is more more pricey; so maybe they are worth the peace of mind.

At any rate, thanks for the response.
Brad

**flybouy** · 08-20-2020, 06:30 AM

Brad if it gives you peace of mind then it's worth it to you. Some folks want to prevent any contingency and others throw caution to the wind. I'm somewhere in the middle I guess, I try to weigh the risk vs the probability and go after the high probability issues.

**JRTJH** · 08-20-2020, 06:35 AM

Now, this is "just my humble opinion" but I'd suspect a lot of people would feel the same:

There's just so much you can "add to a trailer before it becomes too heavy to drag behind an underpowered/undersized 4 cylinder turbocharged grocery getter"...

Most trailers don't have emergency mechanical brake actuators or drag chutes either. The reason is because there's an electrical emergency system to "back up the regular system" and not enough "historical problems" to cause a demand for a "backup to the backup emergency braking system"...

The propane system is "extremely safe" both in design and in execution". How many RV propane fires have you heard about? The one I posted, probably that triggered this thread, is the only one I've seen in several years. According to the design specs of this device, it probably would not have stopped propane flow (from a small leak at a fitting) and that fire would likely have happened, even with two of these devices installed, one on each tank. The "probably overlooked" safety device that failed, especially in a 15 year old trailer, is the LPG detector that didn't alarm or give any indication that there was an "explosive level of propane in the trailer".... Chances are (and I can't prove this) the LPG detector wasn't even hooked up and had never been replaced, or as old as the trailer was, it may not have even had one in it...

So, the "typical industry standard safety device" (LPG detector) was either not working or had been removed and that's what contributed to this "propane fire"...

I'm not suggesting that this flow detector device doesn't work, rather IMHO, it's "overkill to install a backup to the backup to the backup to the designed in backup"....

Now, if we were reading of 30 or 40 or 100 propane explosions caused by catastrophic high flow propane leaks every camping season, they'd probably be "OEM" mandated by RVIA.

We had a saying in all my clinics, "When you hear hoofbeats, think horses, we don't live in Africa, so it's not going to be zebras"..... What that means is: Look for the common problems, not those "one in a million events".....

If concerned with a potential catastrophic leak/explosion, just turn the propane tanks off. After all, if the bottle neck is broken off (possibly from the larger lever of that device) it wouldn't stop the explosion anyway.....

I'm not trying to be negative, just providing my perspective (for whatever it's worth) as to why this device just hasn't become the "answer to all the Zebra hoofbeats" we hear around North America.....

LewisB · 08-20-2020, 06:55 AM

Thanks John - and to all that responded!

If a new RV owner encounters this subject, this thread paints a great picture of the subject. Any user should be able to review this thread and make an informed knowledgeable decision for themselves.

I'm glad I bought the valves, but we have always leaned toward being "insurance poor". As John points out, I better go check my propane detector to make sure it is working.

Cyberian · 08-20-2020, 11:55 AM

Really, more than a bit of a side story- I have an uncle who got a flat on the inside dual of my grandparents' MiniWinnie Class C.

Uncle was and is a bit dense and didn't realize it had happened until it caught fire and set off the pop-off valve(s) on the propane tanks in a locker just behind the rear axle

The inferno was spectacular and melted that Mini to a smoldering heap on the shoulder of I-90. Everybody lived through it and a picture of what was left of the Mini was in the paper

I don't think this valve would've helped much. Likely was a design error putting the propane tanks back there, but operator error was probably the main factor

**flybouy** · 08-20-2020, 01:03 PM

LPG is a liquid held in a tank. When the tank valve is opened the liquid boils off to a gas with the pressure differential of the gas flowing to the appliance. When the tank is exposed to intense heat from a fire the liquid will gas off quickly and potentially burst the tank. The "pop off valve" you reference is a pressure release device to vent that high pressure so no device attached to the tank would prevent that.

Ken / Claudia · 08-20-2020, 07:31 PM

I would think the safety stop valves will work as they say. I do not feel the need to get them, but may at some point.
About 30 years of every 2 years sitting through HAZ MAT training I seen all type of real fires in comm trucks and train cars. Never any RVs. Even though I have a fire investigator certificate from the State of Oregon fire Marshalls Office. RV bottles were glossed over and my training was before OPD valves.
When my full time/long time fire investigator was still alive. I asked him Why do the RV bottles blow up or explode? His answer was no matter if the valve is open/closed IF a fire is burning nearby the heat can and will cause the bottle/tank to vent. Venting propane causes, you guessed it more fire.
So, a leak might be stopped by a on/off valve or a safety stop valve. If the fire is going the bottles or tanks in or on the RV can still blow up from venting propane.
RV fires that I have been at where in motorhomes, the fire started from gasoline and later blew up the propane. I know of a truck camper that caught fire. I later asked the trooper who responded, she did not know why. Owner was flagged over by a another driver due to the rear of the camper was burning and the truck and truck camper were a total loss before the FD arrived. I suppose the insurance investigator may have found out why, but no one was injured so police really did not care.

LewisB · 08-20-2020, 09:02 PM

As Marshall points out, RV propane tanks can BLEVE (boiling liquid expanding vapor explosion) when in close proximity to fire impinging on the tank. It is also true that neither the Gas Stop valves or other devices would prevent a BLEVE. However, I believe the Gas Stop valves serve the purpose of initially limiting adequate gas from escaping to start a fire or support an explosion. Here's a personal example:

We were pulling a smaller (24') 5th wheel and an enclosed motorcycle trailer in the northwest US. While traveling about 60 mph on a narrow 2 lane state Hwy, I heard the dreaded "bang" and felt a shudder as the rear passenger side 5th wheel tire blew. There was no shoulder so I stopped dead center in my lane on the highway. I ran back to inspect the tire and heard a loud hissing sound! The propane gas line (steel pipe) ran down that side of the trailer and just aft of the rear wheel, there was a fitting with a copper line leading to the water heater. The blowout had completely taken out the copper gas line and the propane was running full pipe under the trailer and into the atmosphere! I yelled at the DW to get out of the truck as I went forward to shut off the propane at the 2 bottles in the front of the trailer.

We were VERY fortunate that there was no ignition of this gas that was rapidly escaping out of the ruptured gas line. It is for scenarios like this that I believe the Gas Stop valve would be effective. Had I had the valves back then, they would have immediately shut off the supply at the bottles. The alternative could have been an ignition of the gas with resulting loss of the rig, starting a local fire, putting other vehicles at risk, and potentially even loss of life. So, that's why I spent $160 for two of these valves. Hopefully I will never need them, but...

Thanks again for all the input!

**sourdough** · 08-21-2020, 06:02 AM

Lewis how long ago was the above example? I ask because I had a similar situation a few years back when the tread separated from the tire and tore up the underside including cutting the LP line to the stove in the slide above. I did not have the hissing of the escaping LP. I did turn off the LP tanks but it was really an afterthought. I assumed the regulator cut off the flow when it was severed??

Javi · 08-21-2020, 06:16 AM

Just as a note: OPD valves were first ordered in 1998 but it was at least 10 years before some tanks finally had them.. because any tank made before then did not have to be refitted until recertification. And not all states adopted or implemented the ruling until as late as 2001..

LewisB · 08-21-2020, 06:37 AM

Quote:

Originally Posted by sourdough

Lewis how long ago was the above example? I ask because I had a similar situation a few years back when the tread separated from the tire and tore up the underside including cutting the LP line to the stove in the slide above. I did not have the hissing of the escaping LP. I did turn off the LP tanks but it was really an afterthought. I assumed the regulator cut off the flow when it was severed??

Danny,
I want to say this was 2014 or 2015. Shortly after this incident, we purchased our first diesel and toy hauler. I think this was after the OPD valve transition Javi mentioned. At least, I recall having to replace the tanks on our trailer with re-certified tanks that had the "newer" style fittings. Thanks,

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