Instruction manual
A31A Valve
Instruction Manual
Form 5291
March 2008
13
Table 6. Torque Values for Fasteners
FASTENER NOMINAL
SIZE
RETAINING RING SCREWS GASKET RETAINING BOLTS
NSm InSlbs NSm InSlbs
#10 4.6 41 4.0 35
1/4 11 100 9.2 81
5/16 25 220 19 167
3/8 45 400 33 295
NSm ftSlbs NSm ftSlbs
7/16 72 53 53 39
1/2 112 83 80 59
9/16 161 119 117 86
5/8 225 166 161 11 9
3/4 401 296 286 210
7/8 651 480 447 330
1 976 720 651 480
1-1/8 1356 1000 837 617
Note: These values are based upon standard materials, S66286/N06600 screws and ASTM A193GRB6 bolts. For other special fastener materials, please contact your Emerson
Process Management sales office.
Figure 8. Typical Seal Installation
A5251-1*/IL
INTERNAL
TRAVEL STOP
4. Insert a regular screw driver or other similar tool
under the top edge of seal and gently pry the seal
out of the T-slot area in the valve body. Take care
not to damage the seal or T-slot area of the valve
body. After the seal has been removed, clean the
T-slot area, retaining ring and, if required, polish the
disc (key 2) thoroughly with fine steel wool or other
appropriate material.
To install a new seal, O-ring (key 6), and retaining
ring gasket, follow the appropriate instructions given
below.
PTFE Seals
A maintenance kit with installation tools is available
through your Emerson Process Management sales
office.
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 as shown in figure 8. Around the outside
circumference is one wide groove.
Before installing the seal ring into the valve body,
place the O-ring (key 6) into the wide, outer groove
of the seal ring. Refer to figure 8.
2. Install the seal ring and O-ring assembly in the
valve body. The wider outside diameter of the seal
ring, as marked in figure 8, goes into the T-slot area
of the body (see figure 5). Start the edge with the
wider diameter into the T-slot of the valve body using
a blunt-end screwdriver. If you have a maintenance
kit, use the seal installation tools.
3. Carefully tuck the O-ring downward into the body
T-slot until the seal ring is completely entrapped in
the body T-slot, and it completely covers the backup
O-ring.
4. Re-install the retaining ring and the socket head
cap screws. Tighten the cap screws just enough to
eliminate any movement of the retaining ring. Do not
over-tighten the retaining ring screws. Using a
blunt-end tool, carefully tuck the lip of the seal ring
under the retaining ring.
5. When the seal is under the lip of the retaining
ring, continue to tighten the cap screws according to
standard procedures. Do not fully torque screws at
this time. Final tightening of screws is accomplished
in step 7 of this procedure.