BS336 “instantaneous”fire hose couplings are used by UK fire brigades and other related departments as the standard low pressure fire hose fitting. In addition, some utility companies and contractors that obtain water from mains hydrants also use them. This type of fittings is available in aluminum (for freshwater systems) and gunmetal (for salt water).
When they are installed or in use, the female coupling should fit over the seal with a tapered section, which sits in the matching taper of the male coupling once connected. Activated by the water pressure, this tiny little tapered section forms a watertight seal and can only work well when correctly installed. Nonetheless, a seal that is not activated will cause the couplings to leak at low pressure even though correctly installed.
The use of a “double pull” female fitting enables the operator to handle fire hoses with both hands (one on each lug); however, the “single twist” type of female fitting, mounted on the pipe work, manifold, or tank, allows the operator to operate the mechanism with one hand only because the other hand is holding the male instantaneous coupling.
We offer a wide variety of BS336 items, ranging from instantaneous adapters, branch pipes, fire hose (assemblies), standpipes to international shore connections. Not surprisingly, we have plenty of BSf336 round thread (BSRT) suction fittings (3”, 4”, and 5-1/2” in size) made of aluminum and gunmetal currently in stock.