STRUCTURE, FUNCTION, & MAINTENANCE STANDARD SELF PRESSURE REDUCING VALVE MAIN RELIEF VALVE (PC240LC/NLC-7K) 1. Spring 2. Poppet FUNCTION The relief valve set pressure is set to 2 stages. When power is needed, pilot pressure P is turned ON and the pressure is set to high pressure. OPERATION The relief valve set pressure is determined by the installed load of spring (1). (First stage) It is unnecessary to set the first and second stage individually. The second stage is set when the first stage is set. 1. When pilot pressure P is OFF: Low-pressure setting The set pressure is determined by the installed load of spring (1). 2. When pilot pressure P is ON:
High-pressure setting In addition to the installed load of spring (1), pilot pressure P is applied to poppet diameter d1, so the set pressure becomes higher. 10-88 PC210/240-7K