Fisher A41 Instruction Manual page 17

WARNING
Do not lubricate parts when used in oxygen service, or where the lubrication is incompatible with the process media. Any
use of lubricant can lead to the sudden explosion of media due to the oil/oxygen mixture, causing personal injury or
property damage.
CAUTION
Do not rotate the disc past 90 degrees in the open direction. Rotating the disc past 90 degrees can damage the seal ring or
other component parts.
Note
PTFE, NOVEX, and Phoenix Ill seal rings used in other valve types are not interchangeable with seal rings used in the A41 valve. The
A41 seal rings are not interchangeable with seal rings in any other valve type. To order seal rings for this valve, provide the serial
number on the valve.
1. Installing PTFE seal rings:
a. The valve disc should be open while installing the seal ring. If not, rotate the disc to the open position as shown in
figure 7.
b. Hook the spring ends together, insert the spring (see figure 9) into the groove in the seal ring, and work the
spring into the recess in the PTFE seal ring.
c. Install the seal ring (key 4) assembly into the slot in the valve body as shown in figure 9. Refer to installing the
retainer ring steps below.
2. Installing metal seals:
Note
For metal seals only, it may be necessary to apply dry film lubricant or equivalent moly disulfide to the sealing surfaces of the disc,
seal, and the seal retainer groove. Prior to applying the lubricant, the sealing surfaces should be inspected for injurious defects.
Surfaces can be polished using a scouring pad or equivalent. The edge of the seal that contacts the retaining ring groove should
also be inspected and polished if necessary.
a. Rotate the disc to the open position as shown in figure 7. The seal ring will be damaged if the disc remains in the
closed position during seal and retainer ring assembly.
WARNING
Do not lubricate parts when used in oxygen service, or where the lubrication is incompatible with the process media. Any
use of lubricant can lead to the sudden explosion of media due to the oil/oxygen mixture, causing personal injury or
property damage.
b. Install the metal seal ring assembly (see figure 9).
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