I need a 25mm plain to 20mm screwed conduit adapter.

[BradleyP]

Have an isolator switch with 20mm screwed entries into the bottom. Have existing 25mm conduit I want to run into it. Ideally I need a simple adapter, 25mm plain to 20mm screwed conduit adapter. Does this exist cause I can't google one anywhere.

 

[grumpyjohn01]

You don't say galv or PVC..for galv a 25mm coupler with a 25/20 reducer and a 20mm nipple would do it, for PVC glueing a 20mm male adaptor into a 25mm coupler would probably work.

 

[BradleyP]

PVC conduit.
Thanks for the ideas. Just don't understand why you can't buy a 20mm thread with a 25mm plain. Would be easy to make and adapting at the switch/isolator makes sense to me rather than adapting mid pipe.

 

[littlespark]

Drill out the 20mm threaded hole to 25….. ?

Is it 25mm pipe for a reason? Size and number of cables maybe?

You might find the hole in 20mm adaptor or bush is too small to accommodate.

 

[nicebutdim]

Drill out the 20mm threaded hole to 25….. ?

Is it 25mm pipe for a reason? Size and number of cables maybe?

You might find the hole in 20mm adaptor or bush is too small to accommodate.

Unless there was a good reason for not doing so, I'd also be inclined to enlarge the hole. No point in unnecessarily reducing down from larger size and losing additional capacity which may be helpful in the future.

 

[BradleyP]

Drill out the 20mm threaded hole to 25….. ?

Is it 25mm pipe for a reason? Size and number of cables maybe?

You might find the hole in 20mm adaptor or bush is too small to accommodate.

Unfortunately I don't have a 25mm tap to reinstate the thread.
I'm changing over an external aircon to a pool pump so the 25mm pipe and 4mm2 is already there. But it was wired straight in and now the air con is gone I'm putting an isolator in for the future pool pump.
Have checked the opening and theres enough space for the cable and to drop a future earth in to the pool earth grid.

 

[BradleyP]

You don't say galv or PVC..for galv a 25mm coupler with a 25/20 reducer and a 20mm nipple would do it, for PVC glueing a 20mm male adaptor into a 25mm coupler would probably work.

25mm coupler glued over the 20mm plain/threaded works. It also is a super tight friction fit but obviously not waterproof.
Thanks

 

[BradleyP]

Thanks for the ideas ... I'm going with the 25mm coupler around the 20mm threaded. No internal size loss.