172-65200MA-07 (PCV-1) 8 Oct 2021
12
Troubleshooting
When disassembling or removing the product, wait until the internal
pressure equals atmospheric pressure and the surface of the product
has cooled to room temperature. Disassembling or removing the
product when it is hot or under pressure may lead to discharge of fluids,
causing burns, other injuries or damage.
CAUTION
When the product fails to operate properly, use the following table to locate the cause
and remedy.
Problem
Cause
Diagnosis
Remedy
The primary pressure
increases abnormally
The flow rate is
insufficient
Valve is not open
as its initial setting
Piston/valve body
do not slide due to
scale or build-up
Clean piston,
cylinder, valve body
and valve seat
Replace each
o-ring/back-up ring
with new one
The primary pressure
decreases
Fluid leaks when the
valve is fully closed
Supply pressure is
decreased
Check the supply
pressure
Set the supply
pressure back to
the given pressure
Valve isn
’t
completely closed
Valve is leaking
O-ring under the
valve seat is
damaged, or rust or
scale on the valve
seat/valve body
Replace with a new
o-ring
Clean the valve
seat and the valve
body
(* See NOTE)
Fluid leaks from the
bite type tube fitting on
the side of the cover
Insufficient sealing
of the o-rings on the
piston
Piston o-rings are
damaged
Replace with new
o-rings
* NOTE: Leakage may occur even when the valve is completely closed during operation.
Leakage when the valve is completely closed cannot be stopped by tightening the
adjustment screw.
Do not overtighten the adjustment screw to stop leakage.
If the leak does not stop even after making an adjustment based on the "Relationship
between the set pressure and the number of turns of the adjustment screw", replace
the applicable parts
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
