Graphic CutawayHPLPPFFrom Solenoid Valve (SG)ComplexSchematicSimplifiedSchematicHPLPPFHPLPPFOrifice AOrifice BSpring (Weak)Spring (Strong)Main PoppetPilot PoppetPistonExcavator Main Relief ValveLow PressureHigh PressureVacuum PressureDrain PressureColors LegendMedium Pressure