Datasheet
Regulator with Back Flow Mechanism
AR20K to 60K
44
Be sure to read before handling.
Refer to pages 75 through 78 for safety
instructions and F.R.L. unit precau-
tions.
Specific Product Precautions
Mounting & Adjustment
Warning
1. Set the regulator while verifying the
displayed values of the inlet and outlet
pressure gauges. Turning the regulator
knob excessively can cause damage to the
internal parts.
2. Do not use tools on the pressure regulator
knob as this may cause damage. It must
be operated manually.
Caution
1. Be sure to unlock the knob before adjusting
the pressure and lock it after setting the
pressure.
Failure to follow this procedure can cause
damage to the knob and the outlet
pressure may fluctuate.
• Pull the pressure regulator knob to unlock.
(You can visually verify this with the
"orange mark" that appears in the gap.)
• Push the pressure regulator knob to lock.
When the knob is not easily locked, turn it
left and right a little and then push it (when
the knob is locked, the "orange mark", i.e.,
the gap will disappear).
2. A knob cover is available to prevent
careless operation of the knob. Refer to
Features 1 for details.
Warning
1. When using the regulator between a
solenoid valve and an actuator, check the
pressure gauge periodically.
Sudden pressure fluctuations may shorten
the durability of the pressure gauge. A
digital pressure gauge is recommended for
such situation or as deemed necessary.
Operating Principle
Maintenance
Orange mark
When the inlet pressure (P1) is higher than the regulating pressure, the check valve w
closes and operates as a normal regulator (Figure 1).
When the inlet pressure (P1) is shut off and released, the check valve w opens and the
pressure in the diaphragm chamber q is released into the inlet side (Figure 2).
This lowers the pressure in the diaphragm chamber q and the force generated by the
pressure regulator spring e lifts the diaphragm. Valve r opens through the stem, and
the outlet pressure is released to the inlet side (Figure 3).
Figure 1
A-A
w
Figure 2
Normal
Back flow
w
Inlet pressure
(IN)
Pressure in
diaphragm chamber
Inlet pressure
(IN)
Pressure in
diaphragm chamber
SMC
2 OUT
1I N
Figure 3
OUT
(Outlet pressure)
A
A
OUT
IN
(Inlet pressure)
IN
q
e
r