Casting Iron Hydraulic Control Valve Excavator Komatsu PC300-7 And PC350-7

The main control valve of the PC300-5 is a 6-section valve, integrally cast as a single unit. It can be expanded with 1-3 additional auxiliary valve sections, connected via bolts. The internal oil passages of the valve are interconnected, featuring a compact design that facilitates maintenance. Each valve section controls the direction and speed of an actuator, such as a hydraulic cylinder or motor.

Taking the arm operation as an example:

• Neutral Position: When the PPC (Pilot Pressure Control) valve is in the neutral position, the PPC oil pressure on both ends of the main arm spool is zero. The spool remains centered under spring force, blocking hydraulic oil flow, and the arm cylinder remains stationary.
• Digging Operation: Moving the control lever to the digging position activates the PPC valve, which sends oil pressure to the left end of the main arm spool. This pressure overcomes the spring force, shifting the spool to the right. High-pressure oil then flows through the opened passage, pushes past the pressure compensation valve, and enters the bottom chamber of the cylinder. This extends the piston rod while the oil from the upper chamber returns to the tank.
• Speed Control: The greater the lever travel, the larger the displacement of the main spool. This increases the opening area of the oil passage, resulting in higher flow rates and faster cylinder operation.

We offer perfect interchangeable replacements for many world-renowned brands including Rexroth, Eaton, Parkers, Kawasaki, Tokimec, Sauer-Danfoss, Komatsu and more.