We sell three different sizes of stainless steel hose couplings:
- 1/4" BSP (small)
- 3/8th BSP (medium)
- 1/2" BSP (large)
These sizes match our stainless steel plugs, which are not interchangeable. For example a 1/4" BSP coupling will match a 1/4" BSP plug but not a 3/8th plug.
They fit high pressure hoses and the outlet end of low pressure, low-level spraying lances.
The weight of the coupling and its particular application are the deciding factors when determining the size of coupling. For example, a small and light 1/4" BSP size coupling is appropriate for low level softwash lances that use the stainless steel low-level spray nozzles.
We do not recommend using the larger 1/2" coupling on the end of a low-level lance as it would be too heavy and incompatible with our low-level spray nozzles.
The medium 3/8" BSP size is for the high pressure "whip end" of a high pressure telescopic lance trigger.
The large 1/2" BSP size is for the end of hose reels from a pressure washer. This is because they stand up to the punishment of being connected to a low-level pressure washing lance, or a flat surface cleaner, better the smaller fittings.
We also would not use a small 1/4" coupling on the end of a hose reel from a pressure washer. because it may be damaged and/or clogged with debris.
These stainless steel couplings are tried and tested, rated to 3500 psi, and are fitted with EDPM seals that offer excellent chemical compatibility.