Testing Pressure-Reducing Valves

BY BILL GUSTIN

Every morning at shift change, firefighters throughout North America perform daily apparatus checks and routine maintenance on their equipment. A vital portion of an apparatus check involves operating the pump so that you can depend on it to get water. Generally, this involves engaging the pump, operating the primer, and fully opening every intake and discharge valve while their caps are in place. This "exercises" the valves and facilitates a check of discharge gauges. This is followed by closing the discharge valves and relieving the pressure by operating their respective bleeder valves. Valves are occasionally lubricated to ensure that they will operate easily. No daily pump test would be complete without operating its relief valve or its automatic pressure control governor and the transfer valve on two-stage pumps. When temperatures are above freezing, conscientious driver engineers will connect their apparatus to a hydrant and flow water through every discharge. They also will regularly back flush the apparatus pump and do so after every drafting operation.

Experienced engineers realize the importance of frequently exercising and lubricating every valve on a pump and understand that without frequent use and proper maintenance, valves may become difficult to operate or won't open completely because of corrosion. For example, my department recently found that corrosion had frozen closed some apparatus intake relief valves. We caused this problem by not periodically exercising the valves. This involves raising the pump's intake pressure above the relief valve's setting, causing it to open and dump water. Imagine the condition and reliability of an apparatus discharge valve that hasn't been operated, not even cracked partially open in years. It would be irresponsible for a fire department to send firefighters into harm's way with a hoseline connected to this valve.