Propane pigtail hose connector is leaking

[Boxite]

NPT, or "Nat'l Pipe Thread" fittings look like ordinary bolt threads or ordinary machine-screw threads....but if you look closely you will see the actual threads taper slightly to a smaller size at the open end, and a thicker (larger diameter) at the distant end. This is so that as the fitting is inserted and tightened, the threads are gaining slightly in size...so they will automatically tighten to a leak-free level.
The first pic I have posted is NPT, and this link https://www.amazon.com/Camco-59843-P...il+pipe+thread
is an example of one at Amazon, (if you slide your cursor over the pic on amazon you can see the details of the npt end-fitting.)

The SECOND pic is that of an inverse-flare fitting. It is designed to seal internally against a mating-surface within another brass fitting which looks like a slightly raised area or "bump-with-a-hole" in it. See the pic... and then look at the second link, which is a pigtail with an inverse flare end-fitting. (unfortunate not to see in this angle, but the open end of the brass fitting is a "cone" shape, like looking down into a funnel.)
https://www.amazon.com/Flame-King-10...inverted+flare

Now, to further the examples: Here is an adaptor which, looking inside the female portion, you can see the "bump" with a hole in it to accept the male inverse-flare fitting. The MALE threads of this adaptor is NPT (nat'l pipe thread)...slightly tapered. This would be used if someone purchased an inverse-flare pigtail...but needed to mate it to a NPT regulator.


Of course the better method would be to purchase the correct pigtail to begin with.
Use pipe dope or Teflon tape only on NPT threads. (Never on flares.)
Here's an example... in this last pic (of the inverseflare-to-npt adaptor) you might use pipe dope on the male threads of the NPT portion, but never on the female threads of the InvFlr portion. Why?... because the male threads of the NPT form the sealing surface and need to be sealed...but the inverse-flare fitting seals at the point where the internal "bump" fits up against the internal matching "cone" of the MALE inv-flr fitting. (see that cone at the open end of the second illustration below?)

[Leadvox]

Originally Posted by m.hony

I haven't pulled them off yet...
The ones I bought look very similar to the one in the inverted flare picture except for that very narrow extra hex section. There is just one section of hex head on the ones I bought as well as the ones on the trailer. The hex portion is a little longer on the new ones.
If I remove the old ones and discover I have the wrong thing I will return them, but for some reason I have a feeling these are correct.
So...
Pipe dope or no pipe dope? I got it if I need it.

I do, but... be very careful that none of the tape sticks over into the the end and intrudes on the flare. none of it. if you are using dope it works the same, be sure the flare part of the fitting is clean before you screw it on. The only reason I use it is to add tension to the thread connection. The flare fitting establishes its seal by a clean pressure connection on the flare section of the fitting. there are some great videos on youtube about flare gas fittings.They can tell you how tight to crank it etc.

[m.hony]

What's there has some very thick tape around the threads.


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[Leadvox]

Originally Posted by m.hony

What's there has some very thick tape around the threads.


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It's pretty common to see it everywhere. I used it as a sort of "locktite" material on the threads of my flare fittings.

Oh! I was going to mention, be sure to use two wrenches when disconnecting and connecting the pigtail, one on the regulator to counter pressure the tension on the pigtail you are removing.

[featherbedder]

Originally Posted by Leadvox

The gaskets are inside the tank nozzle. They cannot be replaced, the whole valve assembly has to be replaced. Unscrew your pigtail from the tank and look inside the tank valve, you will see what I am looking at. To replace the valve was around $30. to replace the 30lb tank was $55 (they gave me a deal since it failed after the re-certified the tank.)

I knew of gaskets inside outlet end of valveI did not no why had to pur. new tanks when valve needed replaced. Didn't explain fully why replaced tanks in post, but I'm guilty of doing same thing.

[Boxite]

Originally Posted by Leadvox

It's pretty common to see it everywhere. I used it as a sort of "locktite" material on the threads of my flare fittings.

Oh! I was going to mention, be sure to use two wrenches when disconnecting and connecting the pigtail, one on the regulator to counter pressure the tension on the pigtail you are removing.

If the regulator has a brass-adaptor-fitting between the pigtail and regulator it's very likely an inverse-flare setup. (The regulator is threaded with NPT, and the adaptor is installed in order to accommodate a pigtail with inverse-flare end.)
If one finds oneself in possession of an NPT pigtail...then consider removing the inverse-flare adaptor from the regulator and screwing the pigtail directly into the regulator's npt threads. (using a bit of pipe dope, of course.)

BTW... Teflon tape and pipe dope are commonly over-used. Only a very small amount is appropriate. Excessive amounts will interfere with the very sealing you are attempting. (In fact, pipe threads by design need no sealant at all...especially if both are brass which is self-sealing....as the very design of the pipe thread taper is to assure proper sealing.... the sealant is primarily a lubricant to prevent galling of the threads. Dope or tape is mandatory on steel, zinc, etc.

Tape or sealant on flare fittings can prevent the flare from bottoming onto the sealing surface, so none should be used at all. Simply tighten until firm, then 1/8th turn further only, so as to avoid stripping the threads and deforming the mating surfaces.

Hope this helps. (I passed Plumbing Merit Badge when I was 12.)

[m.hony]

Originally Posted by Leadvox

It's pretty common to see it everywhere. I used it as a sort of "locktite" material on the threads of my flare fittings.

Oh! I was going to mention, be sure to use two wrenches when disconnecting and connecting the pigtail, one on the regulator to counter pressure the tension on the pigtail you are removing.

It had occurred to me to use 2 wrenches to keep from wrenching the regulator right off.

[m.hony]

I bought the wrong propane hose connectors.
The ones I bought were male inverted flare.
Apparently the ones on the trailer are 1/4" MNPT.
In a Google search I find 20-30 male inverted flare to one 1/4" MNPT.
Where do y'all buy them?
I will call/email Airstream tomorrow.


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[HiJoeSilver]

1/4" seems small to me. It's likely 3/8 or 1/2". Try a local large propane supplier like suburban propane. Some that have the big tank trucks have the capability to make hoses. There are lots of places online that sell them.

Check OODM. They have some didn't look to check fittings. VTS has some just have to check fit.
https://gashosesandregulators.com
http://www.propaneproducts.com

[m.hony]

Our "local large propane supplier" doesn't have them.
One the male inverted flare.
The male inverted flare are 10 times more common than the NPT.
I have looked at dozens of websites just like that to no avail.
I called Airstream and got the Airstream part number and Manchester Tank Part number.
I called Manchester tank. They won't sell to individuals, only to factories.
I guess I could check out an Airstream dealer, but it has been my experience in the past that shipping is more than the cost of the item being shipped.
So I took my second shot in the dark on Amazon.
I really think there are only 2 types of RV propane hose connectors- male inverted flare, which I have already bought and found to be wrong, and NPT (national pipe thread?) which is what I believe I have.
The type/style/brand of regulator may determine which type of pigtail.
The type/style/brand regulator on a Classic may be different from the other trailers?
The lady at Airstream emailed me PDFs on 2 styles of regulators- one I've never seen before and 1 like is on my trailer. Maybe the difference is the regulator that automatically switches to the other bottle when one is empty? Maybe they all do that? I don't know.
We'll see if the Camco NPT propane hose connectors I bought off Amazon will work when they get here.
Maybe they will.
If they don't it's back to the drawing board- Airstream dealer or Vintage Trailer Supply.

[featherbedder]

Google Ebay for fittings, also could change regulators to have standard size hoses.

[lsbrodsky]

I just bought mine on Amazon
Larry

[m.hony]

Any Google search, Ebay search, or Amazon search yields dozens of male inverted flare connectors.
I ordered some Camco NPT ones from Amazon.
2 of Camco 59843 20" Pigtail Propane Hose Connectors - Acme x 1/4" Male NPT
Sold by: 4Wheel Online
$25.09
I don't see any others on any other website other than the 1/4", which I assume is talking about the inside diameter of the hose?
Or is 1/4" referring to the part that pushes into the tank fitting when you turn the green knob?

[featherbedder]

Originally Posted by m.hony

Any Google search, Ebay search, or Amazon search yields dozens of male inverted flare connectors.
I ordered some Camco NPT ones from Amazon.
2 of Camco 59843 20" Pigtail Propane Hose Connectors - Acme x 1/4" Male NPT
Sold by: 4Wheel Online
$25.09
I don't see any others on any other website other than the 1/4", which I assume is talking about the inside diameter of the hose?
Or is 1/4" referring to the part that pushes into the tank fitting when you turn the green knob?

It is a little confusing what you need as talking all dif. sizes acme etc. green knob, tank regulator fitting etc. What goes into top of propane tank is valve that large size male fitting w/male push into valve. All standard regulators have inverted flare fitting that hose or copper tubing screws into. One end into tank valve other into reg. [there are some regulators that use npt] I have never seen them in my life time as I have always used standard regulator. Acme threads are what is female in tank valve pig tail end. Acme thread is not commonly used but to stop misuse of IMO critical uses.

[m.hony]

So my regulator is different.
Is that an Airstream thing or a Classic thing or an automatic switching regulator thing?


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[HiJoeSilver]

I'm having a hard time picturing your set up. I know all the parts you're talking about but can't picture what's where. Picture possible?

You might be able to simply get a brass adapter to transition from flare to pipe thread they are available at most big box hardware stores.

I think the yellow Teflon works better than pipe dope in this application.

[featherbedder]

As HiJoeSilver posted can't picture what you have, no idea what you have and post I wrote earlier

[m.hony]

I do not have the Cavagna regulator, but a different brand.
I wonder if I could change the inlets to the regulator to female inverted flare and use the male inverted flare pigtails I already bought. That could be an option.
I do have the NPT hose connectors coming.
Not in a real big hurry.
It is still 91 degrees every day here, but I might need heat by Thanksgiving.
One thing at a time.
Got my new jack installed.
Got my Baked Potato official name registry medallion applied.
Got a bunch of camping reservations and rallies.
It'll be ah-ite.


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[SilverGate]

How I replaced my leaking LP pigtails:

Propane gas leak and summer reading

[Leadvox]

this maybe?

https://www.etrailer.com/Propane/Camco/CAM59953.html

the fittings coming off your regulator might be changed out as well, but i think the fitting above would work if I am picturing your dilemma.