Not a direct fit. Joining 2" NPT (National Pipe Taper) to 2" BSP tapered (R2 / BSPT) needs a 2 NPT to R2 BSP tapered adapter. Sealing method, the real-world trap, and the exact adapter to buy.

Updated 05 September 2026.

HoseFitFinder / Every thread and fitting standard

Connect 2" NPT (National Pipe Taper) to 2" BSP tapered (R2 / BSPT)

How to join 2-11.5 NPT and R2, and what stops it leaking.

Needs adapter
End A
2" NPT (National Pipe Taper) (2-11.5 NPT)
Seals on on the thread flanks with PTFE tape
via adapter
End B
2" BSP tapered (R2 / BSPT) (R2)
Seals on on the thread flanks with PTFE tape or paste
Adapter needed2 NPT to R2 BSP tapered adapter

Not a direct fit. Joining 2" NPT (National Pipe Taper) to 2" BSP tapered (R2 / BSPT) needs a 2 NPT to R2 BSP tapered adapter.

The adapter to buy

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2 NPT and R2 BSPT are both tapered 2 inch threads, which fools people into forcing them together, but the flank angle differs: 60 degree on NPT, 55 degree on BSPT. They cannot seal against each other, so an NPT-to-BSP-tapered adapter is the correct fix.

Both being tapered at 2 inch is the trap. Same taper, wrong flank angle: the joint starts smoothly then leaks. Use the adapter, not extra tape.

Related connections

2" NPT (National Pipe Taper)2-11.5 NPT2" BSP tapered (R2 / BSPT)R22" BSP parallel (G2 / BSPP) to 2" BSP tapered (R2 / BSPT)adapter2" NPT (National Pipe Taper) to 2" BSP parallel (G2 / BSPP)adapter2" NPSH straight hose thread to 2" NPT (National Pipe Taper)adapter2" BSP tapered (R2 / BSPT) to 2" NPSH straight hose threadadapter

Questions and answers

Connect 2" NPT (National Pipe Taper) to 2" BSP tapered (R2 / BSPT)?

Not a direct fit. Joining 2" NPT (National Pipe Taper) to 2" BSP tapered (R2 / BSPT) needs a 2 NPT to R2 BSP tapered adapter.