Female Adaptor 1/4" Tube × 3/4" BSP Flat | AAFAB0409F

Female adaptor 1/4" tube × 3/4" BSP(P), flat seal

Fitting combining a 1/4" push-fit tube connector with a 3/4" BSP parallel female thread with flat seating. It links a tubing line directly to a 3/4" male connection, with no intermediate part.

What "flat seal" means

Unlike a tapered thread, BSP parallel (BSPP) does not seal on the threads. Sealing comes from compressing a flat gasket against the seating face, exactly as on a washing machine connection.

The direct consequence when fitting: PTFE tape or hemp is pointless on this thread, it does nothing and can even prevent the gasket seating properly. What matters is that the gasket is present, in good condition and correctly positioned, and that both faces are clean.

Mind the compatibility

BSP parallel is not interchangeable with NPT or tapered BSP of the same nominal size. Check the male connection thread before ordering: forcing the assembly damages both parts and will never seal.

Applications

Connecting a 1/4" line to a 3/4" outlet: filter housing, tank, softener, manifold, appliance port. The large reduction between the two diameters makes it a take-off fitting, RO system feed, dosing line, treatment appliance return.

Fitting

Check the flat gasket is present and sound before tightening. Tighten hand-tight plus a quarter turn with a spanner, without overdoing it: excessive torque crushes the gasket and causes the very leak it was meant to prevent. On the tube side, cut square with a proper tube cutter and push fully home to the stop, then pull gently to confirm it has locked.

Reference AAFAB0409F.