1 inch slip bulkhead - What the outside thread size?

Hello,

I have a Marineland/Perfecto 75 gallons tank with cornerflow.

I called to ask what size are the bulkheads and they said 1 inch slip. If I understand correctly, that means the inside where you can glue is 1 inch right?

How about the outside thread? Is it 1 1/4?

I want to hook up a threaded to barbed PVC adapter to it...

 

The outside threads on bulkheads are not standard tapered pipe thread sizes or thread counts in most cases so threading fittings on to them is not advised. Even if you can get a fitting to start it will not go on far enough to seal as there is no taper to tighten up on and create a seal.
The outside threads are a straight thread used to screw a jamb or lock nut on.

 

Oh ok.

Thanks, I will see what I can do with what I have.

 

I agree...

 

definitely do not screw anything other than the bulkhead lock nut and foam washer. it will crack and leak. I don't believe they make a slip to barbed adapter but they make a slip to threaded adapter then you can add a thread x barb to the slip x thread. extra piece of plumbing but it will save you from having to order another bulkhead.

 

also, im not sure if you already know this but a 1 inch bulkhead will require a hole bigger than 1 inch depending on the size of the pvc. the title "1 inch" refers to the pvc you will need to connect to the bulkhead itself.

 

I have never been a fan of slip bulkheads, you always end up cutting them apart with a hacksaw when you want to move your tank or modify your plumbing. I use all thread x thread bulkheads so I can reuse them over and over.

I have done a bulkhead FIY sticky post on several forums with lots of good info:
Installing Bulkhead Tips

 

Great info AZDesertRat.

Thats the problem I have with my tank, the previous owner has some fitting glued to the bulkheads and I can't take the overflow and the return apart from the tank...

 

Those seem to be unions. You can do pipe to the slip x thread adapter to the thread x barb.

 

I have the other part, I was able to get some basic plumbing done.

My tank is filling!