TOOL
USAGE
Flathead screwdriver
•
Adjustment of Overpressure and Underpressure Shutoff (OPSO / UPSO) setting
•
Resetting procedure
10 mm / 0.394 in. Wrench
•
Removal and installation of the actuator screws (key 16, Figure 13)
• Removal and installation of body flange screws (key 34)
•
Removal and installation of the lock nut (key 31, Figure 13)
14 mm / 0.551 in. Wrench
•
Removal and installation of the external sense line 1/4 NPT connection (Figure 3)
Internal retaining ring pliers
•
Removal and installation of the fastening ring (key 44)
Table 7.
Recommended Tools
INDICATION
CAUSE
ACTION
If the valve will not close
Operating fault
Check the following:
•
The shut-off pressure settings for high and low pressure values are correct.
•
The O-rings are tight shut.
•
The sensing line is plugged.
Remove the controller and check the following:
•
The reset latch is not stuck.
•
The state of the diaphragm assembly for wear and tear.
Or contact your local Sales Office.
If the downstream pressure in the controller decreases
External leak
Locate and seal the leak.
Or contact your local Sales Office.
If the outlet pressure in the controller is constant
- - - -
•
Bleed off the outlet side of the regulator.
•
Observe the evolution of the outlet pressure (check tightness).
If the downstream pressure in the controller increases
Internal leak
Check the following:
•
The valve plug (disk)
•
The internal interface O-ring (key 46, Figure 14)
•
The reset stem O-ring (key 29, Figure 14)
Or contact your local Sales Office.
Table 8.
VSX4 and VSX8 Series Troubleshooting
•
Using a 10 mm / 0.394 in. wrench, unscrew and
remove the eight spring case screws (key 16)
and associated nuts (key 12) and then remove
the spring case (key 2). For Type VSX4H,
remove the diaphragm support (key 32).
•
To remove the diaphragm assembly, gently grasp
the edge of the diaphragm (key 6) while at the
same time pulling the reset button (key 30) slightly,
which will allow for sliding the back plate (key 5) off
of the cam (key 19).
Grasp the back plate (key 5) and unscrew the
nut (key 31) using a 10 mm / 0.394 in. wrench.
Remove the diaphragm plate (key 7) and inspect
the diaphragm and replace if necessary. The
lock nut (key 31) should always be replaced.
Reassemble in reverse order, ensure to follow
steps outlined in the following section “General
Controller Reassembly Procedures.” Note that
when tightening the lock nut (key 31) onto screw
(key 16), a hexagonal recess exists at the bottom
of the back plate (key 5) that precludes the screw
(key 16) from turning to allow the lock nut (key 31)
to be threaded.
general Controller
Reassembly Procedures
•
It is recommended that O-rings (keys 14 and 24)
be replaced before reinstalling the controller valve
onto the regulator body.
•
Before reassembly, inspect removed O-rings for
damage or wear and replace if necessary.
•
Before reassembly, apply silicone grease lubricant
to the appropriate O-rings.
•
Using graphite molybdenum, grease appropriate
screws, setting nuts and springs (keys 38, 40, 41,
43 and 103).
•
Recommended torque for screws (key 16) is
6.0 N•m / 4.4 ft-lbs.
•
Recommended torque for lock nut (key 31) is
3 N•m / 27 in-lbs.
VSX4 and VSX8 Series
13
