Can i use the outside threads of a 1.5in bulkhead?
 

Can I use a 2in threaded pipe on a 1.5in bulkhead? It seems to fit but I only get a few turns on it. Currently its not leaking.

Well...if it isn't leaking then I suppose it works. The fact that this works would only be based on the specific bh you are using. For example, I know that the Hayward bulkheads that I use do NOT have standard threads for that portion...not even close.

Well I don't think they are standard since I only got couple turns in. How non standard are yours?

Mine are so not standard that you wouldn't be able to even get a NPT fitting onto them.

the threads on a bulkhead are strait threads so the other piece will go on and off easy, pipe threads are tapered so they tighten as they thread on. two different threads which are not compatable. you might be able to get it on a couple threads and it may not leak, but it will be a very weak union which will pull out very easy with a bit of bumping.

Steve

so what you are saying is I should throw a slip in and cement it?

Yup that is what he is saying NST and pipe thread do not mix in any direction umfortunitly, you can get them to start but that is about all.

Bill

yupers. if you are dead set on having threaded, you could use a F slip to M thread bushing to give you a proper threadded end, but threads are also more likly to drip than slip also. so I will always recomend slip and throw in the odd union to take it apart if you need to.

Steve

thats basically what im going to do. Going to have a couple unions and the rest slip.