2-1/2" pump outlet - much tighter threads than my old filter hose

[markcw97]

Friends, I just had to replace my old Pentair #340210 1.5HP pump (see this thread if interested) connected to my Sand Dollar SD40 sand filter. Thankfully, the inlet plumbing and base alignment is perfect and needs no adjustments (sigh of relief!!)

Unfortunately, the 2-1/2" OD pump outlet has completely different threads on it than my very-recently-purchased replacement pump-to-filter hose, although both appear to be the same diameter. The threads on both ends of my hose are much wider than the threads on the pump outlet. I'm posting some pictures here, although I'm not sure if they help. The pump did come with two collars and header blocks (not pictured) - I presume for connecting to PVC pipe, although I'm not sure. (probably one for both inlet and outlet)




Is there some type of adapter than I can purchase (using either inner or outer threads on pump outlet, or even an adapter from 2" PVC to the Pentair-style 2-1/2" threads, that I could use with the adapter collar they provided?
The hose was around $60 and I doubt that I can return it, which kinda stinks if the only answer is a special hose with different threads on each end.

Let me know your thoughts, please! Not having a working pump/filter is getting really old, really fast!! Thank You!

 

[kimkats]

I don't have the answer so here is a bump to see if anyone else has any ideas.

 

[RLP]

The inner threads on the pump look to be NPT, national pipe taper. Also known as IPS. They are a standard thread in plumbing. 1 1/2" npt has 11 1/2 threads per inch. The threads are tapered, and get tighter the deeper you go.

The outer threads are a union type, which is a straight thread. Unfortunately, there is no "standard" union thread size. They are different between manufacturers.

You'll need to determine the thread size and pitch (threads per inch) and find a hose with union ends that matches the pump threads, or pipe it in pvc using standard Npt And the inside threads.

 

[markcw97]

Thanks, RLP. I meant to come back and update this thread last week, but that's exactly what I did - used 1-1/2" PVC and used the inner threads for the connection to the pump. Now to see if the place I bought the new Pentair hose from will take it back...