fuel tank drain questions

[dbhill916]

I'm having some problems threading the Saf Air SA-187 fuel drain into Van's VA-112 on my right tank. It feels like there are no threads to engage on that one and I'm tempted to chase it with a tap. Are there any reasons I should not? If none, does anyone know the thread size/pitch?

Once I get that taken care of, page 21-13 is silent regarding the use of any sealant. Should I use B2 fuel sealant or Loctite 565 ?

thanks in advance,
-dbh

 

[FredMagare]

I don't think that will be a problem but I would be inclined to only clean it to just the first few threads so that I could get the fuel drain started....

I have not used thread sealant on my fuel drains and have had no issues. (I think pipe thread has a bevel for sealing.)

 

[rvbuilder2002]

My recommendation is for reading the Pipe Thread fittings portion of Chapter 5.27 in Section 5 of the KAI.

Standard pipe thread is not 100% self sealing without sealant.

And, if you decide to use a tap, make sure it is a 1/8" NPT tapered tap

 

[dbhill916]

Thank you, Scott.

 

[gasman]

Every builder should have a banner over their work bench that says...
WHEN IN DOUBT READ SECTION 5
Make a copy and pin it to the wall.

 

[rocketman1988]

I don't think that will be a problem but I would be inclined to only clean it to just the first few threads so that I could get the fuel drain started....

I have not used thread sealant on my fuel drains and have had no issues. (I think pipe thread has a bevel for sealing.)

As Scott said, the NPT fittings we use must have a sealant or they will leak. It is the design of the threads.

Also note that the threads are tapered so if you use a standard tap to chase the threads you will destroy them.

Loctite 567 or 565 is the gold standard for sealant.