Add pigtail after auto changeover valve

[x_david_x]

Hello,

I have a Forest River Salem Ice Cabin fish house/toy hauler/RV. It has two propane tanks behind an door on the side of the RV. There is an auto changeover valve between the two tanks, with the output of that going into the RV for the furnace and stove.

I have a portable gasoline generator that I'm considering converting to use propane or gasoline or natural gas. I'd like to be able to connect to the two tanks on the RV to run the generator off propane rather than hauling around another tank and I'd rather not have to disconnect one of the tanks to connect it directly to the generator whenever I need to use it.

Is there a way to add a pigtail (quick connect) after the auto changeover valve, such that I still have a hose going into the RV, but also have the extra hose for connecting other equipment? I need some sort of Y/Tee adapter after the regulator, but I'm not sure where to get such a thing.

Thanks for any help you can provide.

David

[Ford Idaho]

Something like this?

Amazon.com: "LP Gas Extend-A-Stay Tee Adapter Type 1 ACME 1""-20 Inverted Flare Kit System": Automotive

[gasman6674]

Kinda depends on what pressure the genset carb kit needs. You may need to supply it with tank pressure. On most change overs you can not separate the change over head (10psi out) from the second stage (11"wc out) A little more info would be helpful.

[youroo]

Originally Posted by gasman6674

Kinda depends on what pressure the genset carb kit needs. You may need to supply it with tank pressure. On most change overs you can not separate the change over head (10psi out) from the second stage (11"wc out) A little more info would be helpful.

X2 Youroo!!

[sdagro]

If it will run on the low pressure side of the regulator, this what I did. Sorry for no pics but bear with me. Followed the metal pipe coming from the tanks leading to camper to the elbow-removed the elbow and replaced it with a "T", then I assembled fittings to come out below the side of camper and installed kwik connects with the all-in-one cut-off valves. I actually have 3 kwik-connects to run just about everything I have that runs on low pressure LP. Hope this helps. Steve A. Dagro

[x_david_x]

Originally Posted by Ford Idaho

Something like this?

Amazon.com: "LP Gas Extend-A-Stay Tee Adapter Type 1 ACME 1""-20 Inverted Flare Kit System": Automotive

Thank you for the reply! For others reading this, here is a picture of the adapter from the above link:



I believe that would work if I wanted to attach directly to one of the tanks and if I had a regulator in the line to the generator. What I'm trying to do is share the regulator that is already being used for the tanks, which also happens to be an auto changeover regulator/valve. By tying in after the regulator, I can still switch tanks as usual by only removing the connection to the tank (the adapter above would allow for this too), *and* I can run the generator no matter which tank is the active tank (the adapter above wouldn't allow for this).

In other words, just like I don't have to worry about whether I am running my furnace or my stove and don't have to worry about whether one tank is active or another, I'd like that same ability for the generator.

It will probably be easier if I attach some pictures, so I'll take some and add to the thread.

Thanks again,
David

[x_david_x]

Originally Posted by gasman6674

Kinda depends on what pressure the genset carb kit needs. You may need to supply it with tank pressure. On most change overs you can not separate the change over head (10psi out) from the second stage (11"wc out) A little more info would be helpful.

Thanks for the reply. The fuel controller used in the conversion has a max input pressure of 8 ounces, therefore I need a low pressure source (11" water column is just over 6.3 ounces). This is why I want to hook in *after* the changeover regulator, so that I can share that low pressure regulator when using the generator with the RV and take advantage of the auto-changeover without needing to move the generator to the second propane tank.

When I am using the generator without the RV, I'll have another hose rigged up with a hand tight adapter, low pressure regulator, and hose with a quick connect end, so I can easily hook it up to a stand-alone propane tank and snap onto the generator.

I will take some pictures of my tank set-up and post them.

Thanks again,
David

[gasman6674]

In that case if you already have a quick disconnect plumbed into your system use that, If not I would plumb it as close to the outlet of the regulator as feasible the use the biggest id hose you can find. I have a little concern for the regulator btu capacity as I do not know what the max flow on these import unit are. Try it if you have frosting issues or low flame in the unit report back

[x_david_x]

Originally Posted by sdagro

If it will run on the low pressure side of the regulator, this what I did. Sorry for no pics but bear with me. Followed the metal pipe coming from the tanks leading to camper to the elbow-removed the elbow and replaced it with a "T", then I assembled fittings to come out below the side of camper and installed kwik connects with the all-in-one cut-off valves. I actually have 3 kwik-connects to run just about everything I have that runs on low pressure LP. Hope this helps. Steve A. Dagro

Thanks for the reply. I don't have a metal pipe or elbow. However, assuming it is the same type of connection of the flexible hose I have attached to the bottom of the changeover regulator/valve, this does sound like what I need. I just need to know where to get the tee and the fittings for the tee. I was hoping this was a somewhat standard adapter and that there were others who have wanted to run multiple things after the low pressure regulator, but that I just didn't know the name of the adapter. Seems like it is a custom job, but again, I just need to find where to get the right sized tee/y.

You said you have 3 quick connects, but earlier you mentioned a single Tee. If your main line for the RV is on one side of that Tee that would allow for one quick connect on the other side of the Tee. How are you hooking up the other 2 quick connects? I ask, because although I don't need it now, if I did want to run multiple low pressure appliances outside the RV in the future, being able to have multiple quick connects would be good.

My portable Coleman stove (Roadtrip model) has a built in regulator, so if I wanted to use it in the future, I'd need to connect directly to one of the tanks (possible use for the adapter that was first posted above) *and* have the correct hose to adapt to the connector that comes with the stove, which is made for connecting to 1 lb propane tanks.

My less portable triple burner cooker stand (Tejas Smokers) has its own high pressure regulator, so I'd connect that directly to the propane tank as well. Looking more and more like that adapter will still come in handy, just not for the generator.

What other low pressure gear do you have running outside the RV?

Thanks again and I will post some pictures to make this more clear.

David

[x_david_x]

Originally Posted by gasman6674

In that case if you already have a quick disconnect plumbed into your system use that, If not I would plumb it as close to the outlet of the regulator as feasible the use the biggest id hose you can find. I have a little concern for the regulator btu capacity as I do not know what the max flow on these import unit are. Try it if you have frosting issues or low flame in the unit report back

I don't have a quick connect plumbed into the system yet. That's what I'm trying to do.

I too worried about the BTU requirements. Looking online at what others have posted, it is looking like about 30,000 BTU with the generator running at full power (it has an eco mode too, so can run at a lower output as well). My furnace is 20,000 BTU input. Not sure about the stove, but let's aim on the high side and say 3x9,000 BTU and 9,000 btu for the oven too. That's 36,000 BTU. So if I wanted to run the generator on high, all three burners on high, the oven on high and the furnace, all at the same time, I'd be at 86,000 BTU.

I haven't been able to find a changeover regulator that looks like the one I have on the internet and don't know what make/model mine is. However, looking on the internet, I wasn't able to find a changeover regulator less than a 130,000 BTU rating. They are probably assume if you are wanting to use them with multiple tanks, you are probably running a number of devices on them and will need the extra BTUs.

Having said all that, I'm most likely safe from the BTU perspective. However, as you pointed out, frosting is a problem and I believe it to be my biggest problem. I've never been able to find a vaporization rate table for 20 or 30 lb propane tanks online. I've always had to extrapolate based on charts that show rates for a 25% full smaller tank compared to charts that show rates for 100 lb tanks at various fill levels.

Doing this math again, I find that a full tank puts out *roughly* 2.8 times as many BTUs as a 25% full tank (temperature and tank size will affect this, but I'm just trying to get rough numbers). Using the charts that show BTUs for 20 lb and 30 lb tanks, I find that if I use a 20 lb tank, at 25%, at 0 degrees F (again, this time of year, this is being used for ice fishing, so 0 degrees is not unheard of and isn't even the worst case scenario), I'm at only 7,500 BTUs. 2.8 * 7,500 BTUs = 21,000 BTUs. 2.8 * 10,000 BTUs = 28,000 BTUs for a 30 lb tank (what I currently have in the RV).

Obviously, a tank is only 100% full for a short while once it is used, but it does give me a range of 28,000 BTUs when full on down to 10,000 BTUs at 25% and then lower before the tank is regarded as empty by the changeover regulator/valve and the switch is made to the other tank.

This means my furnace will not be able to run at full force and I'm not sure how it will handle getting less than 20,000 BTUs input. Any ideas? Will it cut out when we reach the max vaporization level of the tank at a rate under the 20,000 BTUs the furnace can handle, or will it just run at a lower input/output? I've seen space heaters turn off when they are set at a high output and the tank can't supply that output (due to being low or due to the cold, or both). Before doing the math, I hoped they had figured all this out and that it wouldn't be a problem using the furnace in cold weather. I have to hope the furnace can handle a lower BTU input and will just run longer, but I'd love to hear any information anyone else has on this.

Now, add in the generator, pulling another 30,000 BTUs at full power, and I'm probably going to have serious problems running in cold temps. I could get a regulator that allows me to use both tanks at the same time, doubling the surface area, and increasing my max BTUs. That kind of defeats the benefit of an auto changeover regulator, but if that's what I have to do in the winter, so be it.

Another option would be to use one of the propane tank heater products. They are quite spendy. And, of course, using electricity to run the power for the tank heaters would reduce my effective generator capacity and burn more propane.

All of this won't prevent me from converting the generator over. It may just mean that I can't run it off propane in the winter time on the same tanks that are running the furnace for the RV. If I have to carry around a separate tank (or tankS, considering I may reach a single tank limit quickly in cold weather if I'm drawing a lot of power out of the generator) in the winter and run the generator on that, I guess it is either that or retrofitting the generator to run off a larger gasoline tank. I'm just trying to avoid the gasoline if possible, for a number of reasons.

Thanks again for your insights.

David

[gasman6674]

Cylinders are never 100% full by code is max is 80% so a 20# cylinder will hold 20# of gas 4.24 # per gallon or 4.71 gallons but the wc (water cap) is 47.6# or 5.95 gallons any way if you can upsize (if you have room) your cylinders to a 30# or a 40# you might eliminate the issue. I just attached a chart that I think will help you out.

[x_david_x]

Originally Posted by gasman6674

Cylinders are never 100% full by code is max is 80% so a 20# cylinder will hold 20# of gas 4.24 # per gallon or 4.71 gallons but the wc (water cap) is 47.6# or 5.95 gallons any way if you can upsize (if you have room) your cylinders to a 30# or a 40# you might eliminate the issue. I just attached a chart that I think will help you out.

Thanks for the charts. Those are some of them that I've found on the internet and used to do my calculations. The vaporization rate chart is based on 25% full tanks. I have yet to find one for smaller tanks that shows the full range from empty to full, like they have for 100 lb tanks.

I based my calculations on 100 pounds and 20 pounds and 30 pounds, which already takes into account the 20% reduction. However, that's another variable to be mindful of. Some stations don't give you a full 20 pounds. Usually that is more important for calculating and comparing price/gallon between different stations, but in this case, where frosting is an issue, I'll want to make sure my tanks are as close to the full rating as possible, to increase my runtime before I run into problems.

The RV came with 20 lb tanks. I immediately switched them over to 30 lb tanks, just to give me a longer time in between fills. Just so happens that it will also assist a bit with the possible frosting issue.

I don't have room for 40 lb tanks in the cubby hole where the tanks sit, or I would go with 40 lb tanks. I suppose another option would be to install a couple 40 lb tanks on the tongue of the RV (if they'll fit), rigged with a regulator that uses both tanks at the same time (twice the surface area), and connect the generator to those. That way I wouldn't have to lug tanks around loosely each time I go to the fish house.

The downside to this approach is that I lose the convenience of taking a fully empty tank out and filling it while still having another tank in use. I'd also still have frosting issues when the tanks are closer to empty than full and I'd need to make sure the station is charging for what they put in rather than a flat fill rate, regardless of how much is in the tank when they start, so that I don't effectively pay twice for the left over propane in the tanks.

I just got the generator and haven't used it yet with the house being used for ice fishing. I have a suspicion that I'll be well below the max rating on the generator much of the time. So even though max is estimated to be 30,000 BTU worth of propane, I could be considerably below that. If so, then I may be just fine. There may be some frosting when the furnace kicks on at the same time the generator is running, but there may also be some amount of buffer in the tanks (gas phase propane) that will handle the demand of the furnace until it shuts off, before I run into a reduced BTU output at the tank due to cold/tank level.

I'll just have to try it when I convert the generator. Right now I'm still trying to find the parts for Teeing/Y-ing off the output of the changeover regulator. If anyone has any internet sources for parts to do this, please let me know.

Thanks again for the info.

David

[gasman6674]

You can get the pipe fittings at any hardware or big box store, the quick disconnect from camping world, ebay or your local lp dealer. Most charts are based on worse case. Adding tanks to your tongue is a good idea if you have room then you never have to worry about waking up frozen, You can get a RegO 7525B34 change over from your local LP dealer it will handle 400,000btu.

Good Luck

[x_david_x]

Originally Posted by gasman6674

You can get the pipe fittings at any hardware or big box store, the quick disconnect from camping world, ebay or your local lp dealer. Most charts are based on worse case. Adding tanks to your tongue is a good idea if you have room then you never have to worry about waking up frozen, You can get a RegO 7525B34 change over from your local LP dealer it will handle 400,000btu.

Good Luck

Thanks for the info. I was hoping to find it all put together, but if I have to make it myself, I'll do that.

Well, I feel really stupid, but when I went out to take a picture of my "changeover" regulator, I realized it wasn't a changeover after all! I was *told* it was, so I just believed it. They just have the two tanks teed into the input of a regular low pressure regulator. It is that tee that I need on the other end of the regulator (what I've circled in RED in the picture below) to hook up to the main line going into the RV and to a pigtail going to my generator.

Here is what it looks like now:



I have been in that cubby hole a few times and just never looked at the regulator close enough to realize that it could never function as a changeover, because both tanks are going into the same tee. That would have to be a very special tee to make it work as a changeover.

So, this means that I do have two tanks operating at the same time (if both valves are open) and twice the surface area. If I want to fully use one tank, I'll have to shut off the second tank and only open it when the furnace goes out (wake up frozen, as you said) or generator stops running, which will indicate to me that the first tank is done. If I start frosting up, then I'll have to open up both of them.

I did find a place that has all the individual fittings and I'm guessing one of the tees there will work. X106-B on this page seems like what I need:

Brass Fittings, Valves, Brass Nipples, Disposable Cylinder Adapter, Gas Orifice, Gas Manifold Parts

Here is what it looks like:



I'm hoping that is the same as the tee on the top of the regulator in the picture.

If the bottom of the regulator is 3/8" instead of 1/4", then I need X106-C on that page of adapters.

I probably won't get around to doing any of this for a while, so if anyone reads this and knows of a place that sells a pre-made quick connect pigtail on one end and a screw in connector on the other end (for the RV line), please let me know.

Thanks,
David

[gasman6674]

That tee on the inlet of the regulator may have a (shuttle type) check in it to keep the tanks from cross filling also the male thread on the end of the pigtail is 1/4" male inverted flare. As for a hose and quick disconnect check the Mr. Heater web site for part #'s then you can probably find online @ Amazon, Ebay Etc. PS I have never seen a regulator like that ever. I would switch to a true changeover.

[x_david_x]

Originally Posted by gasman6674

That tee on the inlet of the regulator may have a (shuttle type) check in it to keep the tanks from cross filling also the male thread on the end of the pigtail is 1/4" male inverted flare. As for a hose and quick disconnect check the Mr. Heater web site for part #'s then you can probably find online @ Amazon, Ebay Etc. PS I have never seen a regulator like that ever. I would switch to a true changeover.

I can't be sure, but my suspicion is that the tee doesn't have anything in it to prevent propane flowing between tanks. I say this, because I had the rig out on the ice this weekend for the first time and long story short is that at one point I checked the tanks and they were both frosted to at the same level. When I put the tanks in, one had a lot more propane in it than the other one.

It is possible that the fuller of the two was used down to the level of the other one, but given the little use they've had, I'm doubting that possibility.

When you are speaking of the male thread on the end of the pigtail, do you mean going from the tank hose into the tee or do you mean the south end of the tee that is going into the regulator?

I couldn't find that regulator online, and I looked at a *lot* of pictures on the web. I did find a part number on it somewhere and I think that additional research led me to the conclusion that it is a European part. Of course, I searched online for a regulator that would allow two tanks to be used at the same time and didn't find anything. This led me to guess that everyone just uses a regular regulator and tees into it like the one I have.

I'm guessing this system was put in place due to the fact that this rig will be used on the ice (cold weather) and two tanks being used at the same time will reduce the chances for frosting. Currently, I plan to refill the tanks and then close one off and run on one tank. If using the generator and furnace at the same time frosts the one tank (either due to its fill level or outside temperature), then I'll open them both up as needed.

Without some sort of tank heater, I'll probably just have to live with not being able to completely empty a tank before refilling. I'll just need to make sure the station I choose only charges for the amount they put in, rather than a flat fee per tank.

Thanks again,
David