HI 2000
Pressure intensifier

	On startup the system fills from the low pressure (LP) supply line. When the high pressure (HP) line pressure = the LP pressure, then the system is full. No fluid is dumped until the piston begins its first reverse stroke.
	On the first reverse stroke, the pilot check valve A closes and the fluid in the low pressure cylinder is dumped to tank, allowing the forward stroke to begin again.

Subsequent forward and reverse strokes are shown on the right. With valve A open and valve B closed the piston moves forward to inject fluid into the HP service line. For the reverse stroke valve B is open and valve A closed. The intensifier typically becomes stalled in this reverse stroke position with the LP inlet pressure x the ratio = the HP outlet pressure. In this situation there is no consumption of hydraulic fluid with both pistons in a static state with pressure locked between the valves A and B. The device can sit indefinitely in this position . . . but the instant there is a drop in the HP pressure line, the piston moves forward to recover the desired pressure.