MODULAR
VALVES
Instructions
Solenoid Operated
Directional Valve
(Incorrect) (Correct)
Pilot Operated
Check Valve
(for "A&B-Lines")
Reducing Valve
(for "B-Line")
PTB A PTB A
Solenoid Operated
Directional Valve
(Incorrect) (Correct)
Throttle and
Check Valve
(for "A&B-Lines",
Metre-out)
Reducing Valve
(for "B-Line")
PTB A PTB A
Solenoid Operated
Directional Valve
(Incorrect) (Correct)
PTB A PTB A
Solenoid Operated
Directional Valve
(Incorrect) (Correct)
Brake Valve
PTB A PTB A
Pilot Operated
Check Valve
(for "A&B-Lines")
Throttle and
Check Valve
(for "A&B-Lines",
Metre-out)
Throttle and
Check Valve
(for "A&B-Lines",
Metre-out)
01 SERIES
No.4
Instructions
Caution in the selection of valves and circuit designing
The selection of modular valves, to suit a particular function or hydraulic circuit, are made in exactly the same way as
conventional valves, taking into account of the flow and pressure of each valve to be used. In some cases, the stacking
system may be restricted, so please refer to the following instructions for stacking sequence. Please note, that when
designing a system using modular stacking valves, due consideration should be given to working space for future
maintenance.
Stacking sequence when using reducing valves (for "A"
or "B" line) and pilot operated check valves.
Because reducing valves are spool type, there is an internal
leakage. In the stacking sequence shown in the drawing left
(incorrect), the cylinder moves due to leakage through the
pilot pressure line .
Consequently, retaining the position of the cylinder using
a pilot operated check valve becomes impossible. The
stacking sequence shown in the drawing right (correct) is
required in order to retain the cylinder position.
Stacking sequence when using reducing valves (for "A"
or "B" line) and throttle and check valves (for metre-
out).
In B to T flow in the drawing left (incorrect), pressure is
generated at part with a throttle effect of the throttle
and check valve. Depending upon the pressure so generated,
the reducing valve may perform a pressure reducing
function which causes a shortage of output power of the
cylinder and spoils the smooth operation of the cylinder.
Therefore, stacking sequence in the drawing right (correct)
is required in this combination.
Stacking sequence when using pilot operated check
valves and throttle and check valves (metre-out).
In A to T flow in the drawing left (incorrect), pressure is
generated at part with a throttle effect of the throttle
and check valve.
The pressure so generated acts to shut the pilot operated
check valve and eventually creates an open and shut
operation of the valve repeatedly which may cause the
cylinder to have a knocking effect (the same effect
will occur in the case of B to T flow). Therefore, the
stacking sequence in the drawing right (correct) is required
in this combination.
Stacking sequence when using brake valves and throttle
and check valves.
In the drawing left (incorrect), pressure is generated at
part (a load pressure and a back pressure from
throttle effect). For structual reasons of the brake valve, the
load pressure and back pressure act to open the valve,
therefore, the setting pressure should be more than the
pressure equal to the load pressure plus back pressure (Pa
+ Pb). If the setting pressure is less than Pa + Pb, the brake
valve acts and brakes the movement of the actuator in
operation, this eventually reduces the speed of the actuator.
On the contrary, if the setting pressure is more than Pa +
Pb, shock may occur when braking the actuator since the
setting pressure is too high against the load pressure.
Therefore, the stacking sequence in the drawing right
(correct) is required in this combination.