1 inch NPT element sought

[mcbrew]

Hi there,

I am looking for a 3KW/240V heating element with a NPT thread. I have found many with NPSM threads but have yet to find one with a NPT thread. Has anyone had a similar problem or been able to source one in the UK or in the US?

Shame we all couldn't stick to a single standard!

Cheers!

[sparky Paul]

Shame we all couldn't stick to a single standard!

Yes... preferably British standards!

I presume you have a NPT socket, if all else fails you could get a 1" NPSM (parallel) tap and open it out.

[mcbrew]

Yes it is an NPT socket and yes British standards

Can you explain further

if all else fails you could get a 1" NPSM (parallel) tap and open it out.

[sparky Paul]

As you are probably aware, NPT is the US standard for pipe taper threads. NPS (or NPSM - the M is for Male) is the parallel thread equivalent, so if you can obtain an NPS thread cutting tap, you should be able to recut the NPT thread into a parallel form. I'm no expert on US standards, but AFAIK the thread pitch is the same on the two standards. It is possible that you may need to run a tapping size drill (1 & 5/32") through the existing thread, but I would think it unlikely. Had it been the other way, i.e. NPSF socket and NPT heater, it couldn't be done - the parallel thread's diameter is mainly larger than a properly cut taper.

Bear in mind that whilst a taper is a sealing thread, a parallel thread thread is primarily a mechanical fixing and preferably needs a seal, such as an o-ring or washer, and a sealing face to tighten up to.

I'm always happier with BSP / BSPT.

[mcbrew]

At last I managed to locate a 3kw, 240v Camco heating element that is 1 inch and NPT. Oddily enough Amazon.com sells them for about $10. If only I had known earlier!