bulkhead plumbing question

dmack

New member
I bought a double threaded bulkhead that I will use for a refugium's drain. It's a 1" bulkhead (1 3/4" hole). Where can I find a hosebarb fitting with a female thread to allow me to attach a drain hose? I haven't been able to find one large enough. I don't want to use the inside treads because it will significantly reduce the drain size. Your help is appreciated!
 
From the bulkheads that I have had in the past. Not to say this is the case with yours. The outside threads are not standard plumbing threads. I dont know why, but I never was successful. The inside threads are pretty standard.

When I need to do something like this, I bring the bulkhead to home depot and try screwing on fittings and then I know exactly what size it is.

Also when looking for barbed fittings, the sprinkler isle at home depot is good for smaller sizes, larger ones I go to a garden center. You will find the larger ones in the pond section. Again you could bring the bulkhead there to try them on instead of ordering them online and keeping your fingers crossed.
 
Also as another idea.. Thinner wall pvc for low pressure use is available at Lowes that I have found. The thinner wall will let you have a larger area of flow.
 
Thanks for your input. It does seem the outside threads are a funky size. I went to home depot, but didn't find what I was looking for.
 
Bulkheads are not made to have you use the outter threads. The outter threads are JUST for the bulkhead nut that you use to tighten it to your tank.

It's fine to use the interior threads. It's a 1" bulkhead and you will still get 1" of water flow.
 
The exterior threads are not standard pipe threads and have no particular dimension. They are not intended for anything other than to screw the retaining nut on and thats it.
You will need to use a 1" male iron pipe thread by whatever tube size you want barbed adapter screwed into the interior tapered pipe threads. I have found adapters with a 1" thread by 1.25 or 1.5" tube size on occasion so you can use a larger tubing.
 
<a href=showthread.php?s=&postid=11973957#post11973957 target=_blank>Originally posted</a> by AZDesertRat
The exterior threads are not standard pipe threads and have no particular dimension. They are not intended for anything other than to screw the retaining nut on and thats it.
You will need to use a 1" male iron pipe thread by whatever tube size you want barbed adapter screwed into the interior tapered pipe threads. I have found adapters with a 1" thread by 1.25 or 1.5" tube size on occasion so you can use a larger tubing.

Iron pipe??? Why not use PVC?
 
IP or iron pipe is the thread pattern. PVC uses IP threads too. IP refers to the thread count and thread pitch or taper. When you purchase a PVC male adapter or female adapter it is going to say 1" MIPxslip or whatever, meaning 1" iron pipe threads by slip or socket (glue) joint.
 
Also note that a lot of water can go through a 1" pipe, and if it is just draining under gravity....that flow will match whatever flow you are pumping back in. So, unless you are pumping water in through a larger pipe, the 1" drain should cover it (not too many standard aquarium pumps run larger than 3/4" or 1").

If you want to be safe buy a 1.5" bulkhead, or double up the 1".
 
Another thing I thought of while I was plumbing my overflows (1" slip bulkhead w/ same OD as yours), was to buy flexible pool hose (I found it at lowes in the plumbing section for sale by the foot without the plastic adapter ends). It is just shy of being able to easily thread onto the outside of the bulkhead (like you want), so if you heat it a bit with a hair dryer or heat gun it should make a pretty tight fit. I would apply some teflon tape tot the threads, too.

AquaFlexHose.jpg


I just went with 1"pvc and haven't had a problem, but this might work for you.....
 
I plumbed a few tanks in my basement that I used those rubber adapters on the drain. Each side has the tightening screw with a metal band.
 
The flow is still restricted through the bulkhead because of the internal 1" dimensions but you could find a 1' to 1 1/2" adapter to increase the size. Lowes has a greater selection of fittings/ adapters IMO but usplastics.com has a lot of hose barb connectors.
 
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