Not a direct fit. Joining 2" NPSH straight hose thread to 2" NPT (National Pipe Taper) needs a 2 NPSH to 2 NPT 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" NPSH straight hose thread to 2" NPT (National Pipe Taper)

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

Needs adapter
End A
2" NPSH straight hose thread (2-11.5NPSH)
Seals on gasket in the coupling
via adapter
End B
2" NPT (National Pipe Taper) (2-11.5 NPT)
Seals on on the thread flanks with PTFE tape
Adapter needed2 NPSH to 2 NPT adapter

Not a direct fit. Joining 2" NPSH straight hose thread to 2" NPT (National Pipe Taper) needs a 2 NPSH to 2 NPT adapter.

The adapter to buy

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2 NPSH is a straight (parallel) hose thread and 2 NPT is tapered, so a 2 NPSH hose will not seal into a 2 NPT pipe port despite the matching nominal size. An NPSH-to-NPT adapter presents a tapered male for the pipe and a straight female for the hose.

The straight-into-tapered mistake weeps because the flanks never fully mate. Fit the adapter rather than forcing the 2 hose coupling onto a pipe thread.

Related connections

2" NPSH straight hose thread2-11.5NPSH2" NPT (National Pipe Taper)2-11.5 NPT2" NPT (National Pipe Taper) to 2" BSP parallel (G2 / BSPP)adapter2" NPT (National Pipe Taper) to 2" BSP tapered (R2 / BSPT)adapter2" BSP parallel (G2 / BSPP) to 2" NPSH straight hose threadadapter2" BSP tapered (R2 / BSPT) to 2" NPSH straight hose threadadapter

Questions and answers

Connect 2" NPSH straight hose thread to 2" NPT (National Pipe Taper)?

Not a direct fit. Joining 2" NPSH straight hose thread to 2" NPT (National Pipe Taper) needs a 2 NPSH to 2 NPT adapter.