Covered in detail on the How NOT to Destroy a CAF System Page. To keep debris passing through the fire pump from circulating and possible plugging the small water lines of the heat exchanger, a clean out wye strainer or pump panel mounted basket strainer is added with a collector screen to catch such debris. If enough debris is collected, the screen trap can become plugged preventing water flow to the heat exchanger. This is the number one cause of hydraulic oil overheating. (A Very Bad Thing). With the pump off, the screen should regularly be inspected and cleaned as necessary.
A ball valve can be added to the screen side of the wye clean out strainer. The valve can be opened during pump operations – if the screen is not completely plugged, the pump pressure might blow the debris out of the ball valve.
