Komatsu PC200-8M0 Shop Manual page 191

402 Hydraulic system, Part 2
Functions and operation by valve
In arm "NEUTRAL" operation
q When the arm is operated from arm "OUT" to "NEUTRAL, the pilot pressure from PPC valve is shut off.
q The pressurized oil that flows in through orifice (a) in valve (2) and is drained, is stopped by pilot piston
(1).
q The holding pressure of the arm cylinder bottom side exerts a left-hand force on the right side of ring-
shaped surface, whose area is equal to the area of (S2 - S1) of valve (2).
The combined force of the force exerted on the ring-shaped surface and the spring force of the spring
q
(3) moves valve (2) to the left and shuts off port (A) and port (B).
PC200, 200LC, 220, 220LC-8M0
SEN06120-00
49
10-402