In pump hydraulics, what does EP represent?

In pump hydraulics, what does EP represent?

• A. Engine pressure
• B. Nozzle pressure
• C. Appliance pressure
• D. Back pressure

Answer: (A)

Engine pressure is the pressure produced by the pump itself—the discharge pressure shown on the pump’s gauge. It represents the starting pressure before hose friction losses and elevation changes reduce it along the line to the nozzle. This is the reference point used to work out nozzle pressure: nozzle pressure = engine pressure minus friction losses minus elevation losses. For example, if the pump shows 150 psi and the hose has 20 psi of friction loss plus 5 psi of elevation loss, the nozzle would see about 125 psi. The other terms refer to pressure at downstream points (nozzle, appliance) or opposing pressure, not the pump’s discharge pressure.

Engine pressure is the pressure produced by the pump itself—the discharge pressure shown on the pump’s gauge. It represents the starting pressure before hose friction losses and elevation changes reduce it along the line to the nozzle. This is the reference point used to work out nozzle pressure: nozzle pressure = engine pressure minus friction losses minus elevation losses. For example, if the pump shows 150 psi and the hose has 20 psi of friction loss plus 5 psi of elevation loss, the nozzle would see about 125 psi. The other terms refer to pressure at downstream points (nozzle, appliance) or opposing pressure, not the pump’s discharge pressure.