Abstract: A split, annular hose clamp for clamping one end of a length of thin wall, high pressure, fire hose on the nipple, or insert, of a hose coupling has relatively blunt, alternate ribs and grooves opposite to, fitting and mating with similar ribs and grooves on the nipple and has a pair of machine screws each extending across the butt joint of a pair of one-piece, substantially idential halves in which the heads are within the confines of the head recesses so that there are no sharp protuberances to cut fire hose. The screw heads are socketed for turning and the clamp is of less diameter than the coupling.

Abstract: A gate valve is threadedly attached to an influent port of a motorized pump of a vehicular fire engine at all times. Thus it is not necessary to stop the pump, remove a cap and connect a water supply hose to the influent port. Instead the supply hose is connected to the gate valve, the valve is purged of air, and then opened to connect the new source without air hammer, or flow interruption. A pressure relief valve on the suction side of the gate, relieves pump pressure whether the gate is open or closed.

Abstract: A line relay valve has a valve body with a straight trunk which connects a movable pump to a fire extinguishing nozzle. When the hose lay is several thousand feet, causing severe pressure loss, a first angular branch of the trunk, with a gate valve, is connected to the influent side of a movable booster pump. A second angular branch is connected to the effluent side of the booster pump. Upon opening the gate valve, a clapper swings from first branch blocking position to trunk blocking position to interpose the booster into the system without air intake or water interruption.