172-65200MA-07 (PCV-1) 8 Oct 2021
7
Adjustment
At the time of shipment, the product is not adjusted to the customer
’s specified set
pressure.
By following the procedures below, adjust the primary pressure by adjusting the
adjustment screw of the PCV-1.
After removing the cap and loosening the locknut of the PCV-1, tightening the
adjustment screw clockwise increases the primary set pressure, and tightening it
counterclockwise decreases the primary set pressure.
1. After the PCV-1 is installed on the pipe, temporarily set the adjustment screw to
the desired primary pressure by referring to the graph
“Relationship between the
Set Pressure and the Number of Turns of the Adjustment Screw
” shown below.
The number of turns of the adjustment screw “0” on the graph is the position
where the adjustment screw starts to compress the coil spring.
In addition, follow this step when making adjustments before installing the product,
and follow the procedures below after installing the product.
2. Start supplying fluid slowly and watch the pressure on the primary side with a
pressure gauge.
3. When the pressure is different from the desired pressure, adjust the pressure to
the desired pressure by operating the adjustment screw.
4. After the pressure has been adjusted, retighten the locknut and replace the cap.
NOTE:
Set the pressure based on the number of turns of the adjustment screw
corresponding to the set pressure, as obtained in Step 1 (see graph below).
If the set pressure cannot be obtained even when the number of turns exceeds this
reference value by ± 2 turns, there may be some sort of abnormality.
Make sure the number of turns does not exceed the reference value by
2 turns, and
completely loosen the adjustment screw. Disassemble and clean the product following
the remedies in the
“Troubleshooting” section, then reassemble the product.
After confirming that the adjustment screw is loose, set the number of turns again
according to the steps mentioned above.
The same steps are taken when there is an abnormal leak while the valve is fully closed.
Relationship between the set pressure and the
number of turns of the adjustment screw (Reference value)
No. of Turns of the Adjustment Screw*
(Clockwise)
Please refer to the PMO Value on
the nameplate to determine if 3.0
MPaG type or 1.0 MPaG type.
* Number of turns is from where the
adjustment screw starts to
compress the coil spring.
(1 MPa = 10.197 kg/cm
2
)
(1 MPa = 145 psi)
When carrying out pressure adjustment etc., do not tighten the
adjustment screw further than its lower limit (when the coil spring is fully
compressed and the adjustment screw cannot turn any further).
Failure to observe this precaution may damage the product, leading to
fluid discharge, which may cause burns or other injury.
CAUTION
3.0
2.5
2.0
1.5
1.0
0.5
0
5
10
15
20
25
25
– 65 mm
(1
– 2
1
/
2
in)
80, 100mm
(3, 4 in)
25
– 65 mm
(1
– 2
1
/
2
in)
80, 100mm
(3, 4 in)
Se
t
Pre
s
s
u
re
(
M
Pa
G
)
3.0 MPaG type
1.0 MPaG type
