PVC Sizing for overflow bulkheads

[cd459]

I purchased this overflow box (https://www.marinedepot.com/marine-depot-overflow-box-nano) and have a quick question about pvc sizing since I have no plumbing experience.

It says the bulkhead is 3/4" threaded. Will 3/4" pvc fit directly over the bulkhead or do I need an adapter of some sort to connect them? Also should I glue the pvc to the bulkhead or will the seal be strong enough to prevent leaks?

Sorry if these are basic questions, hoping for some answers to point me in the right direction.

 

[WVNed]

That means a 3/4 threaded male fitting will screw INTO the bulkhead. The outer threads have no function other than to hold the nut that screws up to the tank to attach the bulkhead. You have to follow standard plumbing practices to attach the pipes together with glue for slip fittings or thread sealants for threaded ones.

 

[cd459]

Ok thank you. To make sure I understand correctly, I can use 3/4" flexible pvc to attach to the bulkhead as long as I glue it?

 

[Gablami]

No. Since you have a threaded female bulkhead, you will need an adapter since your flexible pvc does not come with threads. The plumbing terminology is a threaded male adapter, acronym MPT, 3/4”. The other end of the adapter should be a 3/4” socket, but sometimes this is assumed and not specified. Your flexible pvc can be glued into that side.

This link will be helpful to read more:

A Beginner's Guide to PVC Fitting End Types

What's the difference between spigots and sockets? What are male and female threaded fittings? Read this post for information on all kinds of PVC end types!

www.pvcfittingsonline.com

 

[cd459]

No. Since you have a threaded female bulkhead, you will need an adapter since your flexible pvc does not come with threads. The plumbing terminology is a threaded male adapter, acronym MPT, 3/4”. The other end of the adapter should be a 3/4” socket, but sometimes this is assumed and not specified. Your flexible pvc can be glued into that side.

This link will be helpful to read more:

A Beginner's Guide to PVC Fitting End Types

What's the difference between spigots and sockets? What are male and female threaded fittings? Read this post for information on all kinds of PVC end types!

www.pvcfittingsonline.com

So something like this? https://www.homedepot.com/p/Charlot...MPT-x-S-Male-Adapter-PVC021090800HD/203811638

 

[cd459]

I know there are special pvc cements. But would superglue work as an alternative?

 

[jgirardnrg]

So something like this? https://www.homedepot.com/p/Charlot...MPT-x-S-Male-Adapter-PVC021090800HD/203811638

If using hard pvc that should work.

If you using flexible how you want something like this:

Ecopoly 3/4 in. Plastic PEX Barb x 3/4 in. Male Pipe Thread Adapter (5-Pack) 32848 - The Home Depot

Ecopoly PSU insert PEX fittings meet CNSF-14PW and NSF-61 and are manufactured to ASTM Standards F2159, F877 and CSA 137.5 specifications and are ideal for professional installation of hot and cold potable

www.homedepot.com

 

[jgirardnrg]

I know there are special pvc cements. But would superglue work as an alternative?

You need PVC primer and PVC glue... I would not use superglue.

 

[cd459]

Ok awesome, thanks for the help everyone!

 

[Gablami]

If using hard pvc that should work.

If you using flexible how you want something like this:

Ecopoly 3/4 in. Plastic PEX Barb x 3/4 in. Male Pipe Thread Adapter (5-Pack) 32848 - The Home Depot

Ecopoly PSU insert PEX fittings meet CNSF-14PW and NSF-61 and are manufactured to ASTM Standards F2159, F877 and CSA 137.5 specifications and are ideal for professional installation of hot and cold potable

www.homedepot.com

The OP is talking about flexible PVC not flexible tubing. Flexible tubing you should use barbed fittings. Flexible PVC you use regular socket fittings and treat it like hard PVC.

 

[jgirardnrg]

The OP is talking about flexible PVC not flexible tubing. Flexible tubing you should use barbed fittings. Flexible PVC you use regular socket fittings and treat it like hard PVC.

Correct... I missed that

 

[cd459]

The OP is talking about flexible PVC not flexible tubing. Flexible tubing you should use barbed fittings. Flexible PVC you use regular socket fittings and treat it like hard PVC.

Thanks for catching that

 

[Saltyreef]

Just an FYI if nobody mentioned it...
The drain bulkhead on that overflow is likely a slip connection on the inside.
No threaded fittings needed.

3/4" pvc or spaflex will fit just fine.

And +1 youll want to use pvc glue and primer vs anything else.

 

[cd459]

Just an FYI if nobody mentioned it...
The drain bulkhead on that overflow is likely a slip connection on the inside.
No threaded fittings needed.

3/4" pvc or spaflex will fit just fine.

And +1 youll want to use pvc glue and primer vs anything else.

Haha yeah I realized after I got home that it was a slip connection. Do I use the primer and glue on the pvc/bulkhead connection?

 

[Saltyreef]

I primer the inside of the fitting (bulkhead in this case) and the outside of the pipe and then apply glue to the pipe, slip it in and give it a small 1/4 turn to seal everything 100%.

 

[CMMorgan]

I know there are special pvc cements. But would superglue work as an alternative?

NO
Use a primer and then proper glue for your application. Prime both pieces, glue both pieces, 1/4 turn twist as you seat the two together and hold 15 second so it does not push our of a fully seated position. You can get the two pack of glue and primer at any hardware store or even Walmart.