Alamo MACHETE Product Service Manual page 29

CONTROL VALVE - HYDRAULIC
CONTROL VALVE COMPONENTS: Valve Section Components
Each of the 5 Valve Sections (Figure 13 & 14) contains the following Components. Note: Handles shown
in Figure 13 & 14 are not on Valves, They are shown as Illustration Only, On Actual Valve Section there
will be a Hex Head sticking out here, 1/2" Wrench for older Valves (10 Plug Harness) and a 9 mm
Wrench for later Valves (5 Plug Harness). The Later Style Valve (5 Plug) Shown in Figure 13.
1. Segment Compensating Spool
2. Anti-Cavitation Check / Work Port Relief Valve
3. Manual Over Ride Control
4. Mechanical Flow Limiters
5. Main Flow Control Spool
6. Shuttle valve
Pilot Pressure
to the
Proportional
Control System
Main Spool
Shuttle
Valve
Segment Compensation
Spool
SEGMENT COPENSATING SPOOL, Pressurized Oil must pass by the segment Pressure
Compensating Spool before it is used by the Cylinders. The Compensating Spool uses Load Sense
and Spring Pressure to maintain constant pressure drop across the Main spool, Both when the Load
changes and when a Segment with a higher load pressure is activated.
Anti-Cavitation Check / Work Port Relief Valves, Work Port Relief Valves are installed in
the Swing, Lift and Dipper Circuits to limit the max pressure in those particular circuits to a lower
pressure than the Main System Relief. The Anti-Cavitation Check Valve allows Oil to be taken from the
return (Tank "T" Port) galley of the Valve when needed to prevent Cavitation of Cylinder. The Tilt and
Door Valve Sections do not contain these valves.
Main Flow Control Spools, The Flow Control Spools work in conjunction with the Valve Body
to direct the flow of Oil to the Cylinders. The spool is actuated by Pilot Oil Pressure, which is controlled
by the Proportional Control System. It can also be Mechanically operated with the use of an external
Lever or Wrench. Spools cannot be interchanged in the Valve Section due to the special individual
designs of Spools. Maximum Stroke Adjusters are pre-set at the factory and will not need Adjusting.
Load Sense Shuttle Valve, The Load Sense Shuttle Valve located in each Section insures
that the Load Sense Signal from the Valve Section with the highest Pressure is sent through the Load
sense Line.
MACHETE (Service Manual) 04/04
© 2004 Alamo Group Inc.
B
A
Load Sense Connection Ports
29
Anti-Cavitation /
Work Port Relief
Valve
Mechanical
Flow Limiters
Pressure Port
FIGURE 13
Manual
Control
Handle
Illustration
Only