LPG tank pipe fitting
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LPG tank pipe fitting
So I had to yank the old style horizontal 20yr old LPG tank out of the camper yesterday cause the guy at my local place FINALLY said "no" to filling it. I know I should have done it for my own safety a long time ago, but I'm cheap and lazy. He probably should have said no to filling old tanks a long time ago too for his own butt, but that's his buisness.
Anyway.
I had to disconnect the flexible rubber regulator hose from the hard-line to get the tank out (I was able to fill it without taking it out).
I assume that it has an NPT (looks tapered) thread on it, and "technically" tapered threads are supposed to seal dry. I don't trust dry connections.
Should I use Teflon tape when I reassemble? If not, is there some kind of goo I should buy?
Thanks.
Anyway.
I had to disconnect the flexible rubber regulator hose from the hard-line to get the tank out (I was able to fill it without taking it out).
I assume that it has an NPT (looks tapered) thread on it, and "technically" tapered threads are supposed to seal dry. I don't trust dry connections.
Should I use Teflon tape when I reassemble? If not, is there some kind of goo I should buy?
Thanks.
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From: Living under the bosses d
absolutelly not!!!
Tapered fittings are to be used dry. They do not make the seal through the threads they do it on the mateing surface. You will only be masking the leak useing any materials on the threads. If you do not think the ttaper is good change out the line or fitting. For your own saftey... do not use other materials to seal it. f you are in doubt of the fitting being sealed use an approved leak detector or a combustable gas detector. Soap and water have been found to deteriorate the rubber hoses and corrode the lines and is no longer an approved method of leak detection.
Tapered fittings are to be used dry. They do not make the seal through the threads they do it on the mateing surface. You will only be masking the leak useing any materials on the threads. If you do not think the ttaper is good change out the line or fitting. For your own saftey... do not use other materials to seal it. f you are in doubt of the fitting being sealed use an approved leak detector or a combustable gas detector. Soap and water have been found to deteriorate the rubber hoses and corrode the lines and is no longer an approved method of leak detection.
Cargo Master
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From: Living under the bosses d
Originally Posted by 95van
I use teflon tape on flare fittings, but I agree NPT should be dry.
The dope is used for a lubricant primarily. it allows the threads to make contact and not tear each other up.
I am a gas piper by trade and am NFI certified by the HPBA. I have my own business and have delt with pipe and fittings for years and people's lives depend on me, I know what I am talking about. If I did'nt my $10,000 bond would be tapped out from insyurance claims against me.
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From: LaPorte, CO
Originally Posted by MARTYSTOWRIG
I think you may have mis quoted yourself. NPT (national pipe thread) needs to have tape or some type of dope on it to ensure a proper leak free connection.
NPTF is the designation for "dryseal" tapered pipe threads. This configuration has a flat in the root of the thread that is cut into and deformed by the crest of the top of the mating thread form to form a dry seal.
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Well then... what's the difference between a flared and a tapered fitting? do you have any diagrams/pictues, or url links? How do I identify?
Thanks
Thanks
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From: Living under the bosses d
I do not have any good info to help you decide what you have. What I can say is, if you are concerned about the fitting's worthiness take it off and go to your local RV dealer to get a new replacment. Usually RV'S use NPT schedule 40 black pipe and fittings for the propane manifold and Soft copper to the appliance. What is between the black pipe and the regulator is normally 1/4" or 3/8" pigtail hose. What part is the actual part you are concerned about?
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You're right, I posted it backwards. If you look at a tapered connector closely, you may see that the first male threads are going to fit loosely in the female section, then it gets tighter. A flare is the kind of connection you'd make with soft line and a flaring tool, and depends on the seat rather than the threads to seal. The threads of that type connection just draw the seat together, and tape could interfere with the seat.
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