Patent ID: 8776904

Claim:
An ultrahigh pressure firefighting skid unit comprising: a skid platform; a water tank mounted on a portion of the skid platform; a reel and a high-pressure hose wound thereon, the hose terminating in a high-pressure fog nozzle, the reel mounted to the skid platform; a high-pressure water pump forming a source of 800 to 1,500 psi water mounted to the skid platform; an internal combustion engine mounted in driving relation to the high-pressure water pump; wherein the high-pressure water pump has a low-pressure side connected to the water tank; wherein the high-pressure water pump has a high-pressure side; a high-pressure manifold connected to the high-pressure side of the high-pressure water pump; a pressure unloader valve connected in high-pressure water receiving relation to the high-pressure manifold and connected in high-pressure water supplying relation to a first high-pressure hose which is in supplying relation to the reel and the high-pressure hose terminating in the high-pressure fog nozzle, wherein the unloader valve is also connected to a second hose which second hose is in water supplying relation to the low-pressure side of the high-pressure water pump to effect recirculation, the pressure unloader valve having a valve setpoint such that the unloader valve switches from the first high-pressure hose to the second hose when the unloader valve is subject to a pressure higher than the setpoint; an engine idle control valve mounted to the high-pressure side of the high-pressure water pump, the idle control valve operatively connected to the internal combustion engine, the idle control valve having a setpoint such that the idle control valve operates when the pressure unloader valve operates; a run/start valve connected between the high-pressure manifold and the water tank to close or open a connection between the high-pressure manifold and the water tank; a high-pressure relief valve connected to the high-pressure manifold to provide over pressure relief; and a low pressure relief valve connected to the low-pressure side of the high-pressure water pump.