The P-500 weighed about 233 pounds without the suction hose, strainer and two gasoline tanks. Each fuel tank contained 7 ½ gallons of an 80- to 100-octane gasoline and oil mixture. Filled, they weighed 52 ½ pounds each. With a fuel consumption rate of 6.9 gallons per hour, each tank ran the pump for one hour. Most ships carried spare 55-gallon drums of gasoline for the pumps on the fantail; each 55-gallon drum operated the pump for almost eight hours.

The speed of the engine and the water delivery pressure were controlled by a special pressure regulator, which could be set between 75 to 140 psi; it was usually set for 100 psi. At this pressure and using a 4-inch suction hose, the pump delivered 500 gallons of water per minute with a suction lift of 16 feet. With an eductor, the lift could be increased to 50 feet or more, but the water delivery dropped proportionately. The pump could supply six 1 ½-inch hoses with a pressure of 100 psi. It could maintain this pressure using standard all purpose nozzles (APNs), with or without 4- or 10-foot applicators. However, the pump could maintain a pressure of only 75 psi with an eductor in use. This was the performance capability when supplying one 2 ½-inch hose with the APN or three 1 ½-inch hoses with APNs attached, with or without applicators.

For firefighting class Bravo fires topside or below decks, one or two 1 ½-inch hose lines supplied foam using a mechanical foam nozzle (MFN) with the Navy pick-up unit (NPU).

At least eighteen personnel were required to transport the pump and accessories and to rig the pump for deep suction operation. In ship wide or major emergencies, any member of the ship’s company could provide assistance with this and operating the pump. Otherwise, pump teams from repair party lockers operated the pump. The repair lockers with specific P-500 pump teams were 1, 1B, 2 and sometimes 3, depending on the ship’s class.

Suitable means had to be provided to carry the poisonous exhaust gases into the clear, particularly when the pump was used below decks. A standard 2½-inch rubber suction hose was coupled to the exhaust outlet to remove the gases.

Before the pump was placed in operation, it had to be primed with water. One method of priming was to use a hand-operated vacuum pump, to draw air from the pump body, and a 4-inch, hard rubber suction hose, causing these spaces to be filled with water. This method would not work on suction lifts over 16 feet. For higher lifts, bucket priming was used. In this method, the pump body and suction hose were filled through a cap opening on the top of the pump housing. To use this second method, a tight foot-valve on the lower end of the suction hose was used to prevent escape of the priming water and to retain prime.

After being operated with sea water, the pump had to be drained and flushed with fresh water before being restored. The pumps were generally stowed topside in water- and fume-proof sealed covers for safety because of the gasoline tanks, as well as to reduce salt water corrosion.