
Instruction Manual
D500242X012
A31A Cryogenic-Rotary Valve
February 2019
14
1. Locate the replacement seal ring (key 7) 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 (key 8) is provided, fit this over the back of the seal ring (matching seal and backup ring
angles) prior to installation in the valve.
Table 5. Torque Values for Fasteners
FASTENER NOMINAL SIZE
RETAINING RING SCREWS
GASKET RETAINING BOLTS
N
S
m
In
S
lbs
N
S
m
In
S
lbs
#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
N
S
m
ft
S
lbs
N
S
m
ft
S
lbs
7/16
72
53
53
39
1/2
112
83
80
59
9/16
161
119
117
86
5/8
225
166
161
119
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/Inconel screws and ASTM A193GRB6 bolts. For other special fastener materials, please contact your Emerson sales office.
2. Install the seal ring, and if applicable back‐up ring, 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 5.
Figure 5. Typical Seal Installation
16B5081 / DOC
LARGEST OUTSIDE
DIAMETER (KEY 7)
3. Once the seal ring has been fully installed into the valve 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.