Got Bulkhead tips?

[hfmann]

Hey all,

While putting my new closed loop design together, I found two bulkheads in the old system where the flange had broken off from the body of the threaded section. Do I just have two el cheapo bulkheads, or tightened too much, or something else?

First test on the overflow section uncovered a small leak, which led to the discovery of the broken bh. Obviously I want to make this new system last a long time, so what tips you all got to make sure I've got good long lasting, leak free bulkheads?

FYI - my Bulkhead hole is the right size. 1" Bulkhead with the hole just big enough for the male thread to fit through without any extra room around it.

I know to put the rubber gasket on the inside of the tank. Would it help prevent me from overtightening to put another gasket on the outside?

Thanks.
Hal
_________________
great depression

 

[hfmann]

And would teflon tape help? I've never seen anyone put tape on the outside threads, but seems like it would help in case any water did sneak through the inside gasket. What do you think?

Hal
_________________
Ferrari FXX

 

[Anonymous]

Some bulkhead, particularly the one made of nylon, usually is not of good quality. Some bulkhead has thicker wall, and they are more heavy duty. You pretty much can tell from looking at the construction.

The weak part is the ring. If overtighten, most bulkhead just come down one thread, and if not recognized, it will leak. If you keep overtighten it again and again, the thread will stripe, render the bulkhead useless. I never see any bulkhead with a broken flange.

It would not help much to put another gasket on the outside. It does not help when water leak thru the inside since the water can go thru the thread.

Make sure you have good match of the ring and outside thread of the bulkhead. Using softer gasket may help, but quality bulkhead comes with good gasket that you don't have to "upgrade" anyway. Good luck

 

[Acrylics]

Your're kinda stuck using the "el cheapo" bulkheads as the hole size for the beefier Sch 80 bulkhads is larger so the beefier bulkheads won't fit without enlarging the holes. The BH have been defective but may also have simply been overtightened. Try a new BH and see how that goes. Do not put Teflon tape on the outer threads, you will not be able to properly tighed if you do. And do not put a second gasket on for the same reason.

You *can* use a Hayward Sch 80 3/4" bulkhead in the existing (assuming 1 3/4") hole but obviously will not have the same flow.

HTH,
James

 

[hfmann]

How do you decide how tight to make it?

Dang! I've got absolutely no chance to drill out that hole for a beefier model. There's only 5 1/2" between the tank and the wall. That's another reason I want to make sure I get this right the first time.

And...this time I'm putting a union on so at least I don't have to unscrew a bunch of fittings! Got them everyplace else but thought I wouldn't need one here.
Thanks.

Hal
_________________
u.s recession

 

[Anonymous]

You mean the inside portion cracked?

I see that all the time with plastic bulkhead fittings people install on boats. We call them thru-hulls in that application, but they are the same thing. Most of the time its from overtightening, but the second cause is having the piping that goes to it unsupported. This pulls constantly on the bulkhead fitting and will cause the inside portion to crack over time.

Bulkheads are easy to tighten up, since you can tighten them more even after all the plumbing is in place. I put them on hand tight, and then start the system up, if any of them are leaking, well, just a tiny bit of snugging up with a wrench usually does the trick. That way they are not too tight...

 

[hfmann]

I put them on hand tight, and then start the system up, if any of them are leaking, well, just a tiny bit of snugging up with a wrench usually does the trick. That way they are not too tight...

Nice technique! Thanks.

You mean the inside portion cracked?

Yeh, in one case, the whole flange was totally separated from the threads. The only thing apparently holding it on was the fitting I had threaded into the bulkhead. The second one, was only attached about a 1/4 of the way around the the pipe. Amazing! I don't know why I didn't have several floods going at the same time!

A lesson learned - Don't overtighten the dang things.

Hal
_________________
global recession