The electric motor and hydraulic pump (number 1 in picture above) create the oil pressure needed for the oil side of the intensifier. This assembly is normally in the lower portion of the pump cabinet. The electric motor and pump are rated in HP (or kW for metric). Typical pump sizes are 30 HP, 50 HP, 75 HP, 100 HP and 150 HP As discussed in the previous chapter, each pump will have an associated water output volume (gallons per minute) and pressure (psi).

Again it is important to remember that HP is not necessarily an indication of pressure. A 150 HP pump doesn’t necessarily create more pressure than a 50 HP pump. Horsepower is more directly related to water output, since more HP will be needed to create enough power to move the piston/plunger assembly in the intensifier at the required stroke rate.