1/4" NPT thread vs 1/4" BSP
 

Anyone know if it's a major difference.

I have gauges that are 1/4" Male BSP and I need them to temporarily check something, which maybe 1/4" NPT female plastic it's 1000miles away so I can't just go out and look. It maybe BSP, I don't know, all I know is it's 1/4".

But if it is NPT, if a BSP fitting can be bodged on there, then I won't need to but an adapter...it's only to quickly check pressure, 5mins tops, so doesn't matter if it leaks a little. It's plastic thread so it should "give" a little (or strip :o ).

technically you could force it in a few threads, the difference is just the angle of the thread.

Topnof my head 1/4" NPT is 18 thread pitches per inch, and 1/4" BSP is 19 per inch. It would probably cut itself a new thread eventually but on a few pitches you'd probably get away with it. Could try some PTFE tape for a good seal?

That's my thinking; Its just a temporary check, so a bit of PTFE if needed would be fine.

Unless anyone knows if the pressure/vacuum points on a Bombas Saci Winner 150m pump are NPT or BSP, I've already mailed them with no response. :rolleyes:

I would concur with c_o_b, we've forced BSP fittings into NPT threads on American made garbage a few times in the past. So long as it's not a high pressure application you will be fine.

A couple of wraps of PTFE tape would help lubricate whilst you are screwing it in too.

Cheers :thumb:

I have a sneaky suspicion it will be NPT, the Spanish like to mix BSP with Metric and American just for the hell of it :freak3:

possibly the tapping's you're looking to connect to were added by the installation guys to measure the pump or filters 'delta P' therefore the Pump Manufacturer won't know what the guys fitted
http://www.bombasymotores.es/WebRoot...E4/winner1.pdf

The test points are on the pump itself, its part of the pump housing (which you can see in the picture in the above link, part no.6 ); Technically they are drain points, so have a blanking plug, but they double up as test points to check pressure and vacuum. Nearly all pool pumps have this arrangement.

http://images.inyopools.com/cloud/ho...tdh-gauges.png

I have the parts listing which shows the blanking plugs but all it lists it as is 1/4" and no mention of thread type. Marvellous!

if you've got the 1/4'' bsp gauges already, then get a couple of 1/4'' NPT gauges, if you crack the pump housing it's an expensive fix
http://www.ebay.co.uk/itm/Air-Compre...wAAOSwiONYLBJ4

That looks cheap and nasty quality, wouldn't trust it to check tyre pressures :lol1:

Pump is ready for the skip anyway (bearings have gone, motor case rusted solid so can't split it, filter basket is falling apart and the cost of parts plus new seals outweigh the cost of a new pump anyway) so not to fussed if the threads go: Only reason why I need to check is I'm 99% certain its the wrong size pump. Measuring the dynamic head will back up and confirm my calculations. :)

So why do you care if it's NPT or BSP if the units goosed, just bang it in with some ptfe for lube :wonder:

I don't think the cheap and nasty gauges will cause you any problems, especially as you're saying the whole installation is shagged anyway, the cheap gauges will make it look good :lol:

measuring across a pump destined for the skip as you say might not give you the most accurate results :nono:
why not calculate your installations friction losses & head and then match that to the manufactures pump curves, then you'll know if the 150 was & is the correct pump required for your duty
you can always use your neighbours pool :lol: