Hi,

I have an above ground pool that arrived with a solar heater.
I want to install the solar heater on a shed roof.
The pool and pump have threaded connectors (I think they are European 40mm size) and I need to convert them to 1-1/2" PVC pipes.
It seems like I can't find a single piece adapter, so I have to assemble few pieces together.
These pieces have different internal diameter, and for some, it is smaller than the internal diameter of a 1-1/2" PVC schedule 40.

Is it ok to use fittings with smaller internal diameter?
Will it affect the flow in the entire pipe, or is it just going to change the flow rate/pressure in that section, but the rate/pressure in the rest of the (1-1/2") pipe will remain the same?

Thanks,
Joe.

 

It's not great to restrict the flow. And, yes, any restrictive fittings in the system will affect the flow rate through the entire system.

 

JoeJoe -

Did you see these? Looks like it would do it.

https://www.amazon.com/GAME-4560-Con.../dp/B004TYBCEG

 

Thank you for your replies!

I think I was wrong about the 40mm size. Maybe it is 60mm?
How do I correctly measure the threaded size and find a good adapter for it?
I attached images below showing the threaded side measurements.

I need both male and female adapters.
I wonder if this will work for me (adding a 2" to 1-1/2" bushing):
https://www.amazon.com/Gekufa-Fittin...4133038&sr=8-9



CM

Inch

 

Typically the entire water circulation is not sent thru the solar heater. Solar water heaters are slow to work and don't require high water flow. Actually they benefit with slower water flow. You can take a tap off the water return line to go to the solar heater. Many times a separate pump is used for the solar.

 

Thanks everyone!
Spend few hours in Home Depot today.
These fittings are 2", but seems like they have metric threads, so they do not fit normal 2" PVC threads...

I was able to use a 1-1/2" to 1-1/4" bushing for the female side (the bushing goes through the ring above and I glue a 1-1/2" coupling.
For the male side, I'm using flex PVC 1-1/2" to replace the flexible hose I currently have, so with that, I can use the same trick as above.

Pete, thank toy for this insight.
My plan is to have a shortcut before the solar heater, with two valves, so that I can control how much water flow to the solar heater and how much bypass the heater.
Will this work?

 

Based on post #5 you may not need this, but the above is a chart I found long ago (the comments are not mine).

You can see that a 2” PVC pipe has an O.D. = 2.375 inches - and it turns out 2.375 inches = 60.3 millimeters.

2.375 inches would then also be the pipe O.D. measured at the threads.

They state the adapter below is for 2” NPT pipe (and PVC would have NPT threads) and that the adapter is for either male or female threads.

Maybe I misunderstand but it seems like they are equating 60 mm with 2” PVC pipe size, not the actual size which is 60.3 mm (i.e., 2.375 inches).

I’m a little confused - but maybe it would work.

https://www.amazon.com/Gekufa-Fittin...4204644&sr=8-6

 

In theory it should work. Just need to make sure not to reduce flow too much to gas heater.