Interstate LP Gas

[kduplain]

Just had the LP filled by Uhaul. Now I cannot get any appliance to work. The gas is on, checked the fuses, turned the exterior LP switch on. Tried to bleed the lines by lighting the stove. I cannot get any gas to come out of stove, generator and furnace do not work. Can't even smell gas. Is there a toggle which might have been flipped? Should I try and bleed the line using the exterior pressure release valve? How do you do that? Any thoughts would be much appreciated. Thanks

[J. Morgan]

There is an excess flow valve in the system that slams shut when too much propane exits the tank too quickly.

The valve likely shut when you opened the valve too quickly after filling the tank.

Try closing the supply valve for a few minutes and see if the excess flow valve opens.

Sometimes these things are hard to get open after they close. If this is the case, with the supply valve CLOSED, you might have to take pressure off of the system by opening the valve on a stove burner. If this doesn't do the trick you might need to gently tap on the excess flow valve BEFORE SLOWLY opening the supply valve.

1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[Protagonist]

The Airstream Interstate's fill port has a toggle switch right next to it to shut off the flow of propane from the tank. In most states, propane fillers are required by regulation to shut off this switch before filling a built-in ASME propane tank. Open up the black plastic cover behind the right rear wheels, and flip the switch up if it isn't up already.

If it is up already, then you've got other problems.

By the way, J Morgan, the Interstate doesn't have valves as you describe, just a solenoid valve controlled by that toggle switch I described.

[J. Morgan]

I thought that excessive flow valves were required by law, but I fully admit that I can be wrong about that.

Even my BBQ bottle has one of these, I just assumed that these permanent tanks utilized these also.

Sometimes assumptions do precipitate my errors...


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[kduplain]

Thanks. Trying everything include bleeding with overflow valve. Is the regulator capable of locking the flow shut?

[Protagonist]

Originally Posted by J. Morgan

I thought that excessive flow valves were required by law, but I fully admit that I can be wrong about that.

J, although I'm responding to your comment, my reply is mainly meant for the OP, as a quick lesson on Airstream Interstate propane systems…

On the Interstate there is an overflow valve that the person filling the tank has to open in order to tell when the tank is full— fill until propane spits out, and that's 80% full. Perhaps that was what J meant by "excess flow valve"? But the valve doesn't "slam shut when too much propane exits the tank too quickly." You manually open it just before filling, and manually close it just after filling, and it's not in line with the piping to the appliances so opening it doesn't do anything but waste propane. It bleeds the tank but not the lines.

There is a pressure relief valve (AKA pop-off valve) as well, that vents propane if the tank heats up too much and causes the gas pressure to exceed design tolerances. But that valve is normally closed, and shouldn't open at all unless you're at risk of BLEVE (Boiling Liquid Expanding Vapor Explosion).

Other than those two valves, there is only the solenoid valve as I described, which is either all the way on or all the way off, with no positions in between, controlled by the toggle switch next to the fill port. That is the only valve I'm aware of that's in line between the tank and the appliances. If there's another valve to guard against the propane line breaking off at the solenoid valve, it's built into the tank and you have no control over it.

The only way to bleed the propane lines of excess air is to make sure you have propane in the tank by checking the tank level gauge on the control panel (if the guy filling it forgot to close the overflow valve, you might not have any propane in the tank!). Open a couple of windows for ventilation. Make sure the solenoid valve is turned on. Then open up the stove and try to light one of the burners. Preferably using a long-stemmed butane barbecue lighter rather than the piezoelectric spark built into the stove. Light the lighter first and keep it lit, then turn on the burner, so that as soon as propane starts to flow the burner will light. It could take a minute or two to displace all of the air from the lines and get a good flow of propane.

[J. Morgan]

I am unable to find an official link in the time available to me right now, and I am not 100%, but I am 99% that the fixed RV tanks will use an excess flow valve the same as cylinders.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[Protagonist]

Originally Posted by J. Morgan

I am unable to find an official link in the time available to me right now, and I am not 100%, but I am 99% that the fixed RV tanks will use an excess flow valve the same as cylinders.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

Perhaps, but if so, I sure don't know where it is on my Interstate. It's not anywhere that the user can access.

But perhaps not, too. Because there's one distinct difference between the two systems. Any system with a cylinder can be disconnected by the user. The ASME tanks on an interstate are permanently plumbed. The only place where you can manually disconnect anything is at the auxiliary port near the fill port, where you could hook up an external grill. Perhaps there's an excess flow valve there, but with nothing hooked up there in the OPs case, it wouldn't matter.

[kduplain]

Thanks for advice. Looks like it's going into shop in next two weeks. Not planning on going out again until later in month. Happy Holidays.

[J. Morgan]

I am trying to think of a good reason why an Interstate would not use an excess flow valve when every other tank I have seen made in the past 20 years has one.

It may be that they don't use one, but it seems like such an omission might leave AS open to litigation.

These valves can be quite small.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[Protagonist]

Originally Posted by J. Morgan

I am trying to think of a good reason why an Interstate would not use an excess flow valve when every other tank I have seen made in the past 20 years has one.

I've already said that I don't know for sure if it has one. If it does, then it's at the tank, underneath the van where we never see the danged thing. That's not really the point, and we're arguing to no good purpose.

The only part of your original post that I took exception to is this: "The valve (meaning the excess flow valve) likely shut when you opened the valve (meaning the main feed valve) too quickly after filling the tank." Since it's a solenoid switch with only open and closed positions controlled by a toggle switch, and no positions in between, the OP couldn't have opened the main feed valve too quickly and can't open it any slower.

[J. Morgan]

Lol, we are cool. I saw where you mentioned the solenoid valve up the page, I just didn't get that it was the only valve, and not just a secondary safety device.

I apologize for my ignorance.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[wwwtractor]

The solenoid valve coil went bad on my 2016 Airstream Interstate Grand Tour but I was able to fix it. I purchased a replacement from Adventure Airstream in Fairfield, Ca and tried to return it in original package but they would not take it back. So, if anyone needs this valve part number 601875-06 which costs $182 I will pay the shipping to you.

When the coil blew it shut off the propane to all appliances and the generator. It attaches to the shut off toggle switch by the fill connection. I also tried to return it to my local airstream dealer and they refused to take it as well. I checked with Airstream and they said the manufacturer of the valve is Manchester Tank.