Emerson Fisher POSI-SEAL A31A Instruction Manual page 17

Instruction Manual
D500240X012
A maintenance kit with installation tools is available through your
1. Locate the replacement seal ring (key 5) and note the shape of the ring. The ring is wider across one edge diameter
and narrower across the other edge diameter. Also, note the wide groove around the outside circumference. If an
aluminum backup ring is provided, fit this over the back of the seal ring (matching seal and backup ring angles) prior
to installation in the valve.
2. Install the seal ring (key 5) in the valve body by first placing the wider outside diameter of the seal ring into the
T‐slot area of the valve body as shown in figure 6.
3. Once the seal ring has been fully installed into the body T‐slot, the retaining ring gasket can be installed. This gasket
is a thin graphite material. Use extreme care to avoid damaging the gasket while punching one initial screw hole
through the gasket for alignment.
4. Install the retaining ring, and align the screw holes in the retaining ring with the holes in the valve body. Install the
first retaining ring screw through the punched hole in the retaining ring gasket. Install the other retaining ring
screws by pushing them through the graphite gasket and threading them into the valve body.
5. Tighten the retaining ring screws just enough to eliminate any movement of the retaining ring. Do not over‐tighten
the retaining ring screws.
WARNING
Avoid personal injury or property damage caused by the impact of a falling or tipping valve. Support large valves during
maintenance.
6. To complete this step, stand the valve up. Support the valve securely using methods appropriate for the valve size.
If a vise or other clamps are being used, make certain the flange gasket sealing area of the valve body is not
damaged.
7. Manually rotate the drive shaft (key 3) to turn the disk clockwise to meet the seal ring.
8. Place a piece of rubber, or other soft material, between the disk and internal travel stop to protect the disk. With a
rubber mallet, tap the disk until it contacts the internal travel stop. When the disk makes contact with the stop,
manually rotate the disk counterclockwise back out of the seal ring to a 90‐degree open position.
9. The final seating of the retaining ring screws can now be done. For the screw torque values, refer to table 6.
10. Repeat steps 7 and 8 two more times.
Note
When attaching the actuator to the valve, make sure the valve disk is not in contact with the internal travel stop. The valve disk
should be positioned from 0.001 to 0.030 inch (0.03 to 0.76 mm) away from the internal stop in the valve body.
11. Use an appropriate tool (such as a feeler gauge) and position the disk from 0.001 to 0.030 inch (0.03 to 0.76 mm)
away from the internal stop in the valve body.
This adjustment is necessary to be certain that the actuator output torque is fully absorbed by the actuator travel stop
or by the actuator. The internal travel stop in the valve body should not absorb any of the actuator torque.
Emerson sales office.
A31A Valve
February 2019
17