1/4" NPT (1/4-18 NPT)
Where 1/4-18 NPT is used, its real dimensions, and how to connect it to other keg fittings.
Published dimensions
- Designation
- 1/4-18 NPT
- Size / thread
- 1/4-18 NPT tapered
- Fitting form
- tapered, 60 degree
- Seals on
- on the thread flanks with PTFE tape or paste
- Rating / role
- US pipe thread on some regulators, gauges and check valves
Used on: regulator bodies, some manifold ports and inline gauges.
NPT is tapered and seals on the thread, the opposite of a flare. A 1/4 NPT will not seal against a 1/4 MFL flare seat. Going from NPT to flare needs an NPT-to-MFL adapter, and only the NPT end gets tape.
Flare fittings seal on the 45 degree flare face and must never be taped. Push-in fittings seal on an O-ring against the tube wall and need the tube cut square. Barbs seal under a worm clamp. Getting the sealing method right matters more than the thread label, because most homebrew leaks are a taped flare or an unclamped barb.
Connect this fitting
Connect 1/4" NPT to MFL male flare (1/4")needs an adapterConnect CGA-320 CO2 cylinder valve to 1/4" NPTneeds an adapter5/8" BSP beer thread (shank / coupler)related fitting (5/8" BSP (7/8"-14 nut))3/8" BSP shank threadrelated fitting (3/8" BSP (G3/8))MFL male flare (1/4")often confused with 1/4-18 NPT
Sources: MoreFlavor thread types explained (MFL/FFL, NPT, BSP)