Tapered vs straight BSP threads

Hi Elco, can you confirm that your kettle inlets, outlets and HERMS coil etc use BSPP (straight) threads and therefore must be coupled to BSPP female fittings?

I understand that BSPT(tapered) male fittings will work with a BSPP female fittings but not the other way around, so I assume your ball valves, tees, couplers etc are also BSPP?


I am looking to build a HERMS system with some of your hardware so just want to make sure that all of my fittings will be compatible!


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Hi Burn,

The threaded parts are indeed BSPP. The ball valves are also BSPP.

From what I understood, most female parts are BSPP and most standard male parts are BSPT.

Mating BSPP with BSPP has the advantage that it is not tight in just one position: you have a bit of room to line up the parts the way you want them and with teflon tape it seals properly.

Cool, thanks for confirming. Parallel threads are just fine with a bit of teflon tape for sure. Your probably right that female parts are generally BSPP, although BSPT ball valves are not uncommon (I have a few) so this is something to watch out for. Not a problem if buying everything from the BrewPi store of course :wink:

If I have 1/4"bspp male & 1/4" Bspt female both fitting fit leakage…?
W.P. 100 bar
It can be possible… ?

BSPP and BSPT generally don’t mix.

If you are working with 100 bar of pressure, don’t ask your questions on a home brewing forum. Consult an engineer.