Type of bulkhead (wet side + dry side) - threaded + threaded; threaded + slip or slip

[gregzz4]

Originally Posted by byee

I wasn't able to tighten the 3/4" threaded tube into the bulkhead connector

Do you mean it wouldn't start threading, or it wouldn't actually tighten up ?

I have my standpipes just hand tight for easy removal and with tape on the threads they are easy to remove if needed. With them installed this way I get no leakage - my overflow box does not drain down when the pump is off

Does that help ?

[byee]

gregzz24,

I've got 2 standpipes in my overflow for my herbie setup which are using 1" MPT to connect to the bulkheads a my return uses 3/4" MPT to connect to the bulkhead.

I have no problems tightening the 1" MPT to the bulkhead. However, the 3/4" is a real pain to get half the threads into the bulkhead. I've gone as far as trying different brands of 3/4" MPT ends.

If I thread it half way, will this be adequate or will it just develop a leak at a later date?

Thoughts?

[byee]

I wrapped 3 layers of Teflon tape onto the 3/4" return and hand tightened into the bulkhead based on the threads in comparison to the 1" herbie drains which I was able to easily hand tighten all the way.

Perhaps I need to try other 3/4" MPT's.

I decided to test anyways by re-installing the 3/4" return into my cube. Needless to say......it's got a slow leak

Any suggestions?? I've tried 2 bulkheads and 2 different brands of 3/4" MPT's......gets very tight after a few turns into the bulkhead even with the use of Teflon tape.

[MitchM]

I only use silicone for threaded ABS or PVC bulkheads.
It's a great lubricant which makes for smooth tightening.
I used to use teflon tape but it was a real pain to clean off the threads if I took it apart. Teflon tape didn't allow for smooth tightening. The nut would always "jerk" as it tightened up.
If you've ever used a torque wrench, you know what I'm talking about.
You want a smooth tightening, not a jerky one.
I waited 1 day before filling, but 1 day is nothing in this hobby.
Make sure the rubber gasket on the wet side seats evenly.

[WarDog]

Something is not right here. Either your bulkhead threads or your MPT threads are hooped, or are not MPT at all, but you have used two and are seeing the same results. Hmmm. I have 2 suggestions. 1) Teflon goes clockwise around the threads, so as it doesn't unwind as you tighten. 2) You may want to use wrenches to assist in tightening, however go slow and careful not to split female threads. If all else fails get yourself some slip slip bulkheads. Hope this helps.

[byee]

The threads are not damaged. I took my return and a spare MPT SLIP to JL this morning to test fit. They were all really tight.

Teflon tape is wrapped clockwise, basically in the same direction as tightening the return.

Im shying away from using wrenches to tightening just in case I need to remove for maintenance.

Thanks for the insight.

[byee]

OK, I figured it out.

The original 3/4" MPT x SLIP were purchased at Home Depot made by Dura USA and NIBCO. I was not able to hand tightening either one of these MPT's into my bulkhead. Once tightened, removing my hand was very difficult without the use of tools.

I went to Rona to with my bulkhead to try the IPEX ones they sell. I was able to hand tighten the IPEX successfully into the bulkhead all the way as well as removing it by hand......no tools.

IMO, the 3/4" MPT x SLIP are out of spec - bad threads.

Thanks for everyone's help!!

[gregzz4]

Glad you got that sorted out

Now for my other question;
You mentioned you put an o-ring between the bulkhead and the drain pipe
I'm trying to picture how this is possible
If you threaded the drain pipe into the bulkhead that far for the o-ring to touch you'd probably split the bulkhead

You didn't by chance put the drain pipe on the outside of the bulkhead did you ?

[byee]

Here's a quick photo of how I was going to use the O-ring by placing it between the bulkhead and the MPT x SLIP.

[gregzz4]

That o-ring isn't needed

That's your standpipe for a drain correct ?
Just wanted to make sure you're putting the bulkhead gasket inside the overflow and not on the outside of the tank
And the nut goes outside the tank