Safely Connecting Dual 30lb Propane Tanks to RV Low Pressure System

[mmurdocktn]

Ok, I have been back in forth with this High pressure side, Low pressure side. I am not going to us a BBQ for a external use and don't want to discuss anything about that.
I want to tap into the LOW PRESSURE side with 2 30lb LP tanks with "dual" regulator on the tanks. I am using the 2 30lb tanks for extended stay and want to "FEED" the propane system so the furnace and hot water system and the gas stove works.
Don't care about a BBQ for external use.
So can I do this? I have read post that I can, and then I keep reading post that it must go on High pressure side. I am assuming that the people that suggest the high pressure side are using the built in "regulator".
I also have a 24g view that has that internal LP tank with the solenoid. So bigger question do I turn off the "BRASS" dial on the default LP tank when using the external tanks? And if so does the solenoid switch need to be on or off as well? And does that solenoid switch control turn on/off other appliances in RV?
Thank you.

 

[BCam]

There may be a way to do what you describe as a 100% DIY project, but I think you'll be better off installing an Extend-A-Stay kit. It's designed for exactly the purpose you describe. Its function of allowing the use of a BBQ is secondary and you don't have to use it. At $40+, I don't think you'd save much by doing something yourself, propane fittings and hoses are expensive. There are numerous Youtube videos on installing these.

https://www.amazon.com/s?k=extend+a+stay&crid=2OJHDLPUEPRRD&sprefix=extend+a+stay%2Caps%2C344&ref=nb_sb_noss_1

I can't advise you on the solenoid issue.

 

[Morich]

As long as you understand the basics of propane, you can do this.
Tanks have high pressure as that is what keeps the propane in liquid from. End users, whether stove, grill, or other use low pressure or if they have a reg built in, it takes the high and makes it low! That leaves any grill for you to decide if it needs high or low.
Often if we want to add the tank, it is cheaper if we don't have to buy a second reg!

Fine to add the second tank on the high side along with the existing but there may be something to think about when using that setup.
Many prefer to only drain one tank and then go fill it while the second is used. That can be done by only having the tank you are using turned on. If both are on, they may both go dry at the same time?
You can do the empty/fill deal either way as it just depends on how you feel about two trips versus the possibility of waking up with NONE!
For the question of the solenoid, we would have to know year make/model of RV to take a good look to be sure where it is located.
There is a great online parts setup to let you take a look at the parts if it is after the 2010 model year:

Parts Catalog

I normally think of that solenoid as turning off ALL gas use, but it is always better to look first before planning!

 

[Winterbagoal]

The solenoid does turn off all the gas on the high pressure side of the regulator, as I understand it. So, following the plumbing diagrams, it also blocks propane access on the low pressure side of the regulator, by default. Morich, you're correct, AFAIK.
I had an Extend-A-Stay installed under my 2018 Navion 24V back in October 2022 at Lichtsinn RV in Forest City Iowa. Why guess when you can have a licensed certified pro do it was my thinking. They did a great job, and their staff and Ron, are the best.

 

[Morich]

Idea of the solenoid is to turn off propane in case there is something like a stove burner knob out of place to fill the RV with propane but then I never like to put too much stock in the "normal" as things do get changed, so a check is always a good idea in my thinking!

 

[Winterbagoal]

On my Navion, I can crouch down and see the sequence of the hardware as it exits the main tank, so the solenoid on/off valve is the first item in the chain of hardware between the tank and the appliances. After it comes the regulators and any branches to the propane system plumbing to the appliances.

 

[RayIN]

Good advice!

The solenoid does turn off all the gas on the high pressure side of the regulator, as I understand it. So, following the plumbing diagrams, it also blocks propane access on the low pressure side of the regulator, by default. Morich, you're correct, AFAIK.
I had an Extend-A-Stay installed under my 2018 Navion 24V back in October 2022 at Lichtsinn RV in Forest City Iowa. Why guess when you can have a licensed certified pro do it was my thinking. They did a great job, and their staff and Ron, are the best.

Messing with the high pressure might result in burning down his MH and/or severely injuring him.

 

[HiBanky]

I am no expert on this but to the best of my knowledge;

An important safety concern when tying into the low-pressure side of an LP system is to avoid back feeding regulators. If the pressure on the low side exceeds the pressure on the high side, the regulators can be damaged and that can be very dangerous. To avoid this, include a valve between the onboard regulator and the auxiliary tanks regulator. Then, when switching over to auxiliary tanks, close the new valve. Likewise, use a quick disconnect fitting to isolate the regulator on the axillary tanks by removing them when using the onboard tank.

The picture is for an additional appliance and not acceptable for auxiliary tanks.

If there is a qualified person in this conversation, please chime in on my advice.

 

[BCam]

Am I missing something? Is there a reason to not use an Extend-A-Stay?

 

[Winterbagoal]

Good advice!

Messing with the high pressure might result in burning down his MH and/or severely injuring him.

Correct. That's why all the "new plumbing" happens downstream from the solenoid operated open/close valve at the main tank. Probably upstream from the hi to lo pressure regulator. That's how Lichtsinn did my E-A-S install.

 

[HiBanky]

Am I missing something? Is there a reason to not use an Extend-A-Stay?

No, If that is your preference.

 

[Morich]

I guess I must be too simple?
Are there folks out there who do plumbing , whether gas or water and don't turn the gas or water off FIRST?
If I work on the gas on my RV, my first move should always be to turn the gas off at the tank!
If you don't, that gets over into what we might call "culling the flock"!

 

[Rocket&Amy92]

Ok, I have been back in forth with this High pressure side, Low pressure side. I am not going to us a BBQ for a external use and don't want to discuss anything about that.
I want to tap into the LOW PRESSURE side with 2 30lb LP tanks with "dual" regulator on the tanks. I am using the 2 30lb tanks for extended stay and want to "FEED" the propane system so the furnace and hot water system and the gas stove works.
Don't care about a BBQ for external use.
So can I do this? I have read post that I can, and then I keep reading post that it must go on High pressure side. I am assuming that the people that suggest the high pressure side are using the built in "regulator".
I also have a 24g view that has that internal LP tank with the solenoid. So bigger question do I turn off the "BRASS" dial on the default LP tank when using the external tanks? And if so does the solenoid switch need to be on or off as well? And does that solenoid switch control turn on/off other appliances in RV?
Thank you.

I just did this on our 05 Vectra. I added a 3-way manual valve, check valve, and solenoid valve downstream of the pressure regulator and factory solenoid. Then added a line to come out of the 3-way manual valve/check valve/solenoid valve to the edge of the RV with a female quick disconnect (only accessible with the slideout extended so it is protected during travel and easy to reach when parked). I replaced the factory LP gas shutoff 12vdc on/off switch on the interior with a 12vdc on/off/on switch. I have a 30lb tank with regulator and braided stainless hose with male quick disconnect that I use for extended stays so I don't have to unhook the RV and go to a propane filling station for the onboard tank.

 

[HiBanky]

I just did this on our 05 Vectra. I added a 3-way manual valve, check valve, and solenoid valve downstream of the pressure regulator and factory solenoid. Then added a line to come out of the 3-way manual valve/check valve/solenoid valve to the edge of the RV with a female quick disconnect (only accessible with the slideout extended so it is protected during travel and easy to reach when parked). I replaced the factory LP gas shutoff 12vdc on/off switch on the interior with a 12vdc on/off/on switch. I have a 30lb tank with regulator and braided stainless hose with male quick disconnect that I use for extended stays so I don't have to unhook the RV and go to a propane filling station for the onboard tank.

Sounds like you have an elegant solution. Some pictures would be nice.

 

[Rocket&Amy92]

Sounds like you have an elegant solution. Some pictures would be nice.

 

[HiBanky]

It a thing of beauty.

mmurdocktn you need to see this.​

 

[Hclark89]

Ok, I have been back in forth with this High pressure side, Low pressure side. I am not going to us a BBQ for a external use and don't want to discuss anything about that.
I want to tap into the LOW PRESSURE side with 2 30lb LP tanks with "dual" regulator on the tanks. I am using the 2 30lb tanks for extended stay and want to "FEED" the propane system so the furnace and hot water system and the gas stove works.
Don't care about a BBQ for external use.
So can I do this? I have read post that I can, and then I keep reading post that it must go on High pressure side. I am assuming that the people that suggest the high pressure side are using the built in "regulator".
I also have a 24g view that has that internal LP tank with the solenoid. So bigger question do I turn off the "BRASS" dial on the default LP tank when using the external tanks? And if so does the solenoid switch need to be on or off as well? And does that solenoid switch control turn on/off other appliances in RV?
Thank you.

I have been using an extend a day fitting so I can run off a 20 lb tank for months. No issues. They come with a secondary port for accessories, but I don't use it. It is no consequence.

 

[HiBanky]

I have been using an extend a day fitting so I can run off a 20 lb tank for months. No issues. They come with a secondary port for accessories, but I don't use it. It is no consequence.

Another excellent solution but on the high-pressure side of the regulator. I'm not sure why he wants to tap the low side but he must have a good reason. Oh, because he is using a dule tank setup with regulators of there own.

 

[klook]

I recently used the high side and a 30 lb tank on my cruise out west. Simple to put in a T with multiple hook up points for different fittings. Turn off the Asme tank and turn on the 30 lb. Done. Low side is fine if you want to use separate regulators. Just be sure and use them. But I would have a shutoff as it will damage the regulator if you apply high pressure on the low side.