I needed to install a second propane bottle supplying my motor home with an auto changeover valve. You would think that this would be a fairly easy project. Not so! It seems that the government has got involved. I have no idea why in their infinite wisdom they have decided that I cannot use a changeover valve without having a pressure regulator attached to it.

There is already a regulator installed and attached to my on-board propane tank along with an electric shut off valve in case the propane detector inside detects a propane leak. There was already installed by the previous owner an Extend-A-Stay kit and I had attached a long high pressure propane hose and I was using that with an external 100 pound bottle. Of course the bottle would always run out at the most inopportune time forcing me to crawl out of bed, get dressed and go outside and change tanks. I can't ever remember it running out while I was dressed except when I would come home to a cold coach.

Okay, you have the reason. I went looking for a change over valve with a high pressure outlet so I could connect to the motor home. It turns out that you cannot purchase one unless you can find one in an antique store. It is all hearsay but I understand that the government has decreed that all change over valves must be permanently attached to a regulator. I don't know why and I don't care. I just know that I needed one and so I decided that I would need to build one.

Since I claim to have a Masters Degree in Southern Engineering I decided to accept the challenge to put one together. I had no idea what I was in for but accept the challenge I did.

First I spent quite a bit of time looking around town for parts but no one sold what I needed. I then went on a business trip to Dallas so while I was there I checked with a few RV dealers and still could not find anything to do the job with so I started looking for parts to build my own assembly.

All of the parts needed are off the shelf but one must be modified. Knowing what I know now and I will document here I could do it again with much less stress. The stress was not knowing if I would be able to get things working or if I was just wasting money buying a bunch of parts that I would not be able to use.

The parts list is pretty well what you might expect. A changeover valve with a pressure regulator attached. Two extension hoses to attach to the changeover valve going to the two tanks and a fitting to hook the existing hose to the new assembly and a few adapters to hook everything together and some ingenuity to re-work and assemble to something safe and workable.

I use a Cavagna North America Automatic Changeover with Two-Stage Regulator assembly part number 36-1-110-0194. If I were to do it again this is the only part I would insist on duplicating. All the other parts are just standard propane parts that can be found at any well stocked propane supply house. Here is what it looks like:

This is the piece that must be modified. The modification is straight forward and really not too difficult. The problem was that I had no idea what I would find when I separated the regulator from the changeover valve. It turns out the modification was not that difficult. The first thing is to separate the two assemblies. I just cut the regulator off with a metal cutting saw making sure to cut near the regulator since I had no plans to re-use the regulator and I didn't care if it were damaged.

The next thing was to remove the collar so I could get to the solid outlet of the changeover valve. I used a Dremel tool cutoff wheel to split the collar in two. One cut on each side of the collar made splitting it easy with a screwdriver.

This exposes the inner output port with a now destroyed restrictor assembly consisting of a spring, ball and seat that I discarded because it was not needed because that function is already part of the system in the motor home.

The brass seat is loose and can be easily removed and discarded along with the ball and spring behind it. What is left is a ⁷/16^th inch hole with three guides inside that were used to hold the ball centered in the shaft. The hole size turns out to be the exact size required for a ¼ inch NPT tap. A ¼ inch tap will work to thread the hole with some extra effort because of the ridges. The tap can be worked into the hole with some extra effort and taking time not to damage the valve or the threads that are already cut.

I enlisted the help of a friend that has a small metal working shop at his house to help me. Had I not done that I would have proceeded cutting the threads like it was steel. I learned that cutting cast aluminum requires a little more effort. First off you must use a different type of lubricant. Cutting oil just will not work. Aluminum requires a special cutting fluid and much more back and forth motion cutting just a little each cut. Plus since the ridges were inside the hole we had to take extra care not to damage the housing.

We were very careful not to get any shavings in the changeover valve since I was fearful that it might cause permanent damage.

Now all that remained is to assemble the parts. I used a ¼ inch brass close nipple, a ¼ inch to ¾ inch brass reducer and a ¾ inch brass collar and a standard propane tank valve plus two propane tank hoses.

And here is the final assembly showing the bracket that came with the changeover valve and regulator assembly. I fabricated a U bold to secure the whole thing and make it more rigid for protection.

Now all I have to do is disconnect the hose from the single propane tank and connect it to the valve on the left of the above photo and then connect the two hoses to the two tanks and I'm finished. Now I have the choice of using one or two tanks with the added bonus of the extra length so I can place the two tanks a little further from the motor home.

I have hooked it up and it works very nicely. I didn't track expenses but the total out of pocket expense was about $160.00.

I have explained what I did and if it gives you any ideas then great. However I must tell you that I cannot recommend that you try this. In fact, I must suggest that you do not. I cannot be responsible for any problem, damage or injuries sustained if you attempt anything described here.

Two Propane Bottles Hooked to Extend-A-Stay® Kit

This is how I did it.