Adjustment Procedures; Maintenance Procedure; Troubleshooting - Yoshitake GP-2000 Installation & Operation Manual

7.2 Adjustment
Follow the steps below, and slowly turn the adjusting screw to set pressure. Incorrect adjustment
may cause hunting, water hammer, etc., resulting in damage to the valve and other equipment. ( See
6.1 Example of piping .)
(1)
Check that all stop valves (V
(2)
Open the stop valve (V
(3)
Open the stop valve (V
Taking sufficient time not to blow the safety valve, blow off the fluid to remove foreign matter.
After blowing, close the by-pass line glove valve.
(4)
Loosen lock nut [28] and turn adjusting screw [27] counterclockwise to release spring [24] (no
compression).
(5)
Open the sensing pipe stop valve (V
(6)
Open the stop valve (V
the stop valve (V
(7)
Confirm that the condensation is discharged from the inside of the pressure reducing valve,
and slowly open the stop valve (V
(8)
Slowly turn the adjusting screw clockwise while observing the pressure gauge on the outlet
side, and set the desired pressure.
(9)
When the entire system has stabilized, conduct fine adjustment as necessary.
(10)
After adjustment, tighten the lock nut.
(11)
Check for leakage. Conduct re-tightening as necessary.

8. Maintenance Procedure

8.1 Troubleshooting

Problem
1． Incorrect pressure is being used.
2． Screen [15] is clogged.
3． Main diaphragm [12] is damaged
4． Orifice of tee [33] is clogged.
5． Pilot valve [17] and pilot valve seat
Pressure does not
reach the desired
6． Sensing pipe is clogged.
value.
7． Nominal size is too small for the
8． Pressure is not adjusted correctly.
9． Wrong installation with tee [33]
10． Strainer installed before pressure
11． Pressure gauge is faulty.
1． Foreign matter exists between main
Reduced pressure
raises above than
the specified value.
to V ) are closed.
1 7
) for the trap installed before the pressure reducing valve.
6
) and adjust the valve travel of the by-pass line glove valve (V
3
).
4
) at the outlet side of the pressure reducing valve. Adjust the travel of
2
) so that a little fluid flows.
3
) on the inlet side.
1
Cause
[18] are clogged with foreign matter,
scales, etc.
specifications.
reducing valve is clogged.
valve [11] and main valve seat
[12], or scratches exist.
1． Correct the pressure.
2． Disassemble and clean the screen.
3． Remove pipe C [36] at elbow [32]
and open the by-pass valve. If the
fluid runs out from elbow, replace the
main diaphragm.
4． Remove the orifice and clean it.
5． Disassemble pilot valve assembly, and
clean it.
6． Disassemble and clean it.
7． Change
appro-priately.
8． Observe the adjustment procedures
and readjust pressure.
9． Install the tee whose slit should be
faced upward (Refer to Fig.10).
10． Disassemble and clean it.
11． Replace it.
1． Disassemble and remove the foreign
matter. When any scratches are
identified, lap the main valve and
main valve seat. Change the parts if
scratches still exist after lapping.
-12-
Solution
the nominal size
■EPDT-014f■
).
5