tapered/NPT -vs- straight/BSP - is BSPP worth the cost?

[orangetree]

In another life (work $ + robustness requirements) we would go BSPP 100% given the choice. It's a better design, relying on the elastomeric seal is generally regarded as being much more robust than relying on sealant and thread deformation.

Custom hydraulic work, on my own, is new to me, though - and BSP is double the cost, with lower availability in the US. What are your thoughts on NPT vs BSPP?

The project I need to complete is a handful of as-compact-as-possible little bends, tees, etc to shove some check valves where they aren't commonly placed, integrated with a few new directional circuits. Requirements include 2500-3000psi, with no significant temperature exposure, minor physical damage concern (it's a tractor), and critically I'll undoubtedly need to be disassembled/reassembled a time or two.

Thanks!

 

[WranglerX]

IF its all about availability go with the one that gives you more choices and more product availability..... NPT has been around for a million years, its not that difficult to get proper thread seal with some of the sealing chemicals available today,,,,

Thread Sealants

Thread sealants prevent fluid leaks on metal pipes and joints

www.henkel-adhesives.com

 

[oldnslo]

In the USA SAE O-ring boss is very common port style and fittings are usually available at any decent hydraulic store.

 

[oldtimer 66]

Go to the Surplus Center in Lincoln Nebraska. Here is the link to there hydraulic section. Hydraulics | www.surpluscenter.com. Then go to there Hydraulic Adapters and Fittings section. They have about any thing you would want in hydraulic components plus tons of other products. They also show the on hand quantities. I have bought there in years passed will no problems.

 

[MtnViewRanch]

In another life (work $ + robustness requirements) we would go BSPP 100% given the choice. It's a better design, relying on the elastomeric seal is generally regarded as being much more robust than relying on sealant and thread deformation.

Custom hydraulic work, on my own, is new to me, though - and BSP is double the cost, with lower availability in the US. What are your thoughts on NPT vs BSPP?

The project I need to complete is a handful of as-compact-as-possible little bends, tees, etc to shove some check valves where they aren't commonly placed, integrated with a few new directional circuits. Requirements include 2500-3000psi, with no significant temperature exposure, minor physical damage concern (it's a tractor), and critically I'll undoubtedly need to be disassembled/reassembled a time or two.

Thanks!

Why would you use anything other than JIC or O-ring boss fittings for all your plumbing?
JD is big on face seal fittings.

 

[orangetree]

Why would you use anything other than JIC or O-ring boss fittings for all your plumbing?
JD is big on face seal fittings.

Well, thats sort of the impetus fpr the question. Putting in an surpluscenter order, they stock the BrandHyd checks i was looking for - but (literally) 2x the cost for the flatfaced vs taper, and even they have ~30 npt's in stock, but only 3 bspp's (i need 4

So yeah, parrallel, flat sealing are way better - but in my first attempts to source availability is bad - looking for opinions on if its just a fools errand to try to stay away from taper.

 

[etpm]

In my experience of over 40 years of machining, much of that making hydraulic parts that used various types of fittings, NPT threads are used for situations where the fitting is usually only to be assembled once, and when high pressure is involved NPT fittings were rarely used and when used they were made o be assembled only once, period. In fact, when tapered threads were used it was usually NPTF, AKA Dryseal. Really, tapered threads are best used in low pressure assembled once situations. It is definitely worth it to spend more money on systems that don't rely on the threads for the sealing but instead other seals, such as o-rings.
Eric

 

[ericm979]

JIC except where you connect to something with a different type of fitting. It's really common in the US and works well.

 

[kennyd]

Why would you use anything other than JIC or O-ring boss fittings for all your plumbing?

^^^^
THIS.

ORFS for a distant 3rd. NPT should be outlawed.

 

[oldnslo]

NPT has one advantage over other fittings in that they rarely fail and cause and oil mist which is very important fire zones like quench tank for heat treat furnace. They typically just drip. On O-ring boss or BSPP with elastomer seal when seal fails you get mist.

This is the only advantage I can think of other than cost for NPT.