Firefighting foam dispensing system PPW MK3

waterflow-regulatedcontinuous-flow

SKUM PPW MK3 wide range proportioning systems function by maintaining equal pressures in the foam concentrate and water inlets to the proportioner. This balancing ability and a variable orifice allows the proportioner to be used over a wider range of flows and pressures than standard balanced pressure pump proportioners. The system utilizes a centrifugal or positive displacement foam pump to pressurize foam concentrate in the supply manifold. A pressure control valve located in the return line to the foam concentrate storage tank is set to maintain a regu lated pressure in the supply manifold at a minimum of 1 bar to 2 bar (14.5 psi to 29 psi) higher than the maximum pressure in the water supply line. Foam concentrate that is not required by the proportioner returns to the atmospheric storage tank through the pressure control valve. When installed in a closed head wet sprinkler system, the proportioner operates in the following way: 1. With the proportioner correctly installed in the sprinkler riser, the water pressure is equal on both sides of the proportioner. 2. As the sprinkler heads open during a fire situation, foam concentrate enters the water stream through a precisely machined metering tube. 3. As more sprinkler heads open, the increase in water flow causes the deflector to open further, increasing the orifice size on the metering tube, allowing more foam concentrate to enter the water stream. This feature gives the proportioner the ability to correctly proportion at both extremely low flow rates and at extremely high flow rates Each proportioner consists of the following components: Cast bronze body Bronze pressure balancing valve