TM 5-4310-393-14
2.
Inspecting the Inlet Valve
a.
Check all parts for condition and acceptable measurements. Refer to Table 4-1 for wear limits.
b.
The inlet valve should be replaced if It no longer closes tightly. The bore diameter of the valve seat
should be 4.0 mm.
C
Install
1.
Installing the Valves. Reassemble the 3rd stage valves and valve head using replacement parts as needed
Proceed as follows:
a.
Reinstall the intake valve (Figure 4-11, Item 13) in the reverse sequence of its removal
b.
Insert the discharge valve (8) with the O-ring (7) into the valve head (10).
c. Position the valve head cover (6) Do not use a sealing compound on the third stage valve head.
d. Insert and torque the valve head cap screws (5) to 18 Ib.-ft (25 Nm = 2.5 kgm) in a diagonal
sequence before tightening the socket set screw (4) in order to avoid damage to the valve head cover (6).
e.
Screw in the set screw (4) with hex key. Fit the gasket (3) and the plain cap nut (2) and tighten with
an open end wrench.
f.
Reinstall the tube connections to the valve head (10).
Table 4-1. Compressor Repair Data
Stage
Item
Max.
min
in
mm
in
mm
Discharge valve spring length.
0.945
24
0.827
21
First
Discharge valve stroke.
0.049
1.25
0.039
1
Valve seat bore diameter
0.049
1.25
Discharge valve spring length
0.945
24
0.827
21
Discharge valve stroke
0.041
1.05
0.031
0.8
Second
Discharge valve seat bore
0.315
8
Inlet valve spring length
0.413
10.5
0.354
9
Inlet valve stroke
0.049
1.25
0.039
1
Inlet valve seat bore
0.492
12.5
Discharge valve seat bore
0.157
4
Third
Inlet valve stroke
0.047
1.2
0.031
0.8
Discharge valve stroke
0.047
1.2
0.035
0.9
4-27
