Connecting to return bulkhead with threads (inside/wet side)...

[Biff0rz]

My tank is used and the 3/4" bulkhead is thread x thread (pic attached). I ran my return piping to it and plan to connect to it with a 3/4" male pipe adapter (another pic). I plan to cement the 3/4" pipe to the male pipe adapter. Do I then cement the 3/4" male pipe adapter to the inside of the 3/4" bulkhead? Or should I use something else like plumbing tape? I think I read a lot of people have leaking issues with the thread x thread bulkheads - so I was considering just cementing it.

 

[DCR]

I would suggest using a street elbow to turn down immediately and minimize the bending moment on the bulkhead. I am assuming you are returning on the back side of the tank rather than the bottom. Not sure if they are available in Sch 80 which looks like what you are planning to use. You can certainly cement the threads and it will not leak. If you want to thread it, you should probably use pipe dope instead of Teflon tape. I think there is less chance of it leaking, or splitting the bulkhead because you used too much tape. I have never threaded into the bulkhead except to the flange side which I tend to think is a little stronger but this means you have the extension in the tank.

 

[Biff0rz]

I would suggest using a street elbow to turn down immediately and minimize the bending moment on the bulkhead. I am assuming you are returning on the back side of the tank rather than the bottom. Not sure if they are available in Sch 80 which looks like what you are planning to use. You can certainly cement the threads and it will not leak. If you want to thread it, you should probably use pipe dope instead of Teflon tape. I think there is less chance of it leaking, or splitting the bulkhead because you used too much tape. I have never threaded into the bulkhead except to the flange side which I tend to think is a little stronger but this means you have the extension in the tank.

Nope, this is on the bottom of the tank. Attached is the best pic I have of it. I'll take a better pic tomorrow. Two on the left are drains. The one on the right is the return. I have it all dry fit, nothing is glued (yet).

 

[Biff0rz]

bump again, will be cementing the return pipes soon...

 

[DCR]

It will work. Just make sure the bulkhead fittings are sealed well (gaskets) since you will not be able to break them apart after the piping is set.

 

[Biff0rz]

It will work. Just make sure the bulkhead fittings are sealed well (gaskets) since you will not be able to break them apart after the piping is set.

Thanks! Yep, bulkheads are for sure sealed. I got those locked down and filled the overflow to test for leaks, it's been leak free for a week.

 

[KStatefan]

I like to use Megaloc thread sealant on plastic pipe threads.

 

[Biff0rz]

I like to use Megaloc thread sealant on plastic pipe threads.

Thanks. I assume I could use this as an alternative? It says it seals the same stuff. I'm asking because Lowes & HD don't have the megaloc in stock unless shipped.

RectorSeal 1.75 oz. #5 Pipe Thread Sealant 25790 - The Home Depot

The RectorSeal 1.75 oz. number 5 pipe thread sealant is ideal for lubricating and protecting threaded connections on metal, PVC, CPVC, polyethylene and reinforced fiberglass pipes. Not recommended for

www.homedepot.com

 

[KStatefan]

Thanks. I assume I could use this as an alternative? It says it seals the same stuff. I'm asking because Lowes & HD don't have the megaloc in stock unless shipped.

RectorSeal 1.75 oz. #5 Pipe Thread Sealant 25790 - The Home Depot

The RectorSeal 1.75 oz. number 5 pipe thread sealant is ideal for lubricating and protecting threaded connections on metal, PVC, CPVC, polyethylene and reinforced fiberglass pipes. Not recommended for

www.homedepot.com

I have never used it but if it says PVC I would assume it will work.

 

[ca1ore]

I've moved to solvent weld slip bulkheads. Threads on the ABS ones tend to be a bit loose and can be a pain to seal. Plus, they're cheap if you have to cut one out.

 

[Sharkman89]

The threads on bulk heads are only meant for the nut holding it to the aquarium, just glue a piece of pvc pipe to the inside. Unless you’re using a inside threaded bulkhead

 

[Biff0rz]

The thread sealant worked, woo. Yes, the bulkhead has a threaded inside. This was a used tank so I reused their bulkheads w new seals.

 

[Biff0rz]

Welp, it's still leaking, ***.

Attaching some pics. I applied the thread sealant and it didn't hold very long. So I cleaned it off and tried Teflon tape... Nope.

Is the bulkhead abs?? I may have used the wrong stuff? I think the fitting it pvc sch 80 and maybe the bulkhead is abs?? I'm not sure at this point what to do. I really don't want to pull the bulkhead of possible....

Pictures are of it installed, me uninstalling it halfway to show the Teflon tape on it, fully u installed to show how the tape failed, then the stuff j tried prior to the tape.

Thanks for any help.

 

[Biff0rz]

This is what I purchased to screw into the inside (wet side) of the inner threaded bulkhead (3/4")

Schedule 80 Male Pipe Adapter

Male Thread x Slip. PVC Pipe Adapters for your plumbing needs. Use Male Pipe Adapters when a transition from a threaded female fitting to the pipe is necessary. Common applications include pumps, sumps, and bulkheads. More professional look than white Schedule 40 PVC. ½” Schedule 80 Male Thread...

www.bulkreefsupply.com

 

[schuby]

I used this stuff to seal my two pressurized returns. It seals very well and you can unscrew them later.

 

[DSEKULA]

I use gasoila pipe sealant, there are 21 threaded bulkheads on my dt and another 7 in my sump, with no leaks.

 

[Biff0rz]

Right, I think I used the wrong stuff. Just below it on the description it says "for ABS pipe use RectorSeal T plus 2".... Which is the red bottle which you have. Not the yellow. This is what I get for reading too fast and rushing..

 

[schuby]

I got mine from a plumbing supply store. They recommended it and I chose to believe them.

 

[DSEKULA]

Right, I think I used the wrong stuff. Just below it on the description it says "for ABS pipe use RectorSeal T plus 2".... Which is the red bottle which you have. Not the yellow. This is what I get for reading too fast and rushing..

Yepp, happens to the best of us
Thankfully it's an easy fix. I watched a plumber I subbed once use the wrong pvc glue to build a whole public water treatment plant (well I didn't personally watch that part) when they released water every connection leaked and/or blew. At least you found this now not with gallons of water everywhere

 

[RobB'z Reef]

Welp, it's still leaking, ***.

Attaching some pics. I applied the thread sealant and it didn't hold very long. So I cleaned it off and tried Teflon tape... Nope.

Is the bulkhead abs?? I may have used the wrong stuff? I think the fitting it pvc sch 80 and maybe the bulkhead is abs?? I'm not sure at this point what to do. I really don't want to pull the bulkhead of possible....

Pictures are of it installed, me uninstalling it halfway to show the Teflon tape on it, fully u installed to show how the tape failed, then the stuff j tried prior to the tape.

Thanks for any help.

I think you may be conflating standards. ABS and PVC are types of plastic and have nothing to do with the thread types they may or may not be. Typically most schedule 80 threaded fittings conform to the NPT standard. You can Google more information on that (national pipe thread). The common bulkheads sold that are made of ABS plastic should conform to that of NPT as well. However manufacturing tolerances and the difference in material types can lead to less satisfactory results. Usually plumbers putty or a quality pipe tape applied in the correct fashion can result in a leak free joint. However, for peace of mind and as dirt cheap as these bulkheads are I'd recommend getting a slip fitting on your exit side and doing a solvent weld. The end that goes to the inside of your tank can be whatever works for you. Being that the fitting is used you are taking you're chances that the threads may or may not be compromised. This advice is just my opinion based on years of general plumbing experience that has nothing to do with reefing but still applies.