Type EZH Relief or Backpressure Regulator
6
Main Valve and Actuator Maintenance
NPS 1 through 3 / DN 25 through 80
Disk Maintenance (Refer to Figure 4)
For Type EZH:
1. Remove nuts (key 26).
2. Carefully lift the upper actuator casing and lower actuator
casing assembly (keys 11 and 5) off the body (key 1).
3. Remove the hex socket cap screws (key 33) and lock
washers (key 32). Lift off the disk holder assembly
(key 30) and disk retainer (key 31).
4. Remove the O-ring (key 29). Inspect the O-ring for
damage or wear, and replace if necessary. Lightly
lubricate O-ring before placing in the sleeve adaptor
(key 27).
5. Remove the cage (key 3), seat ring (key 2) and O-ring
(key 34). Inspect the O-ring for damage or wear, and
replace if necessary. Lightly lubricate O-ring before
placing in the body (key 1).
6. Set the seat ring (key 2) back in the body (key 1) with the
curved side down and the seat edge up. Place the cage
(key 3) on top of seat ring. The cage will engage the step
on the seat ring.
7. Place the disk holder assembly (key 30) and disk retainer
(key 31) on the sleeve adaptor (key 27).
8. Insert the lock washers (key 32) and hex socket cap
screws (key 33) and tighten. See Torque Specifications
(Table 3) for proper torque values.
9. Carefully lift the upper actuator casing and lower
actuator casing assembly (keys 11 and 5) and place
on the body (key 1). Secure with stud bolts and nuts
(keys 24 and 26). See Torque Specifications (Table 3) for
proper torque values.
NPS 4 / DN 100 Disk Maintenance
(Refer to Figure 4)
1. Remove cap screws (key 77).
2. Carefully lift the cap (key 70) off the upper actuator
casing (key 11) and unscrew the eye bolts (key 35) from
the cap (key 70).
3. Remove O-ring (key 75). Inspect the O-ring for damage
or wear, and replace if necessary.
4. Remove the O-ring (key 69). Inspect the O-ring for
damage or wear, and replace if necessary. Lubricate
O-ring before placing inside the cap (key 70).
5. Remove special screws (key 68) from sleeve (key 14).
6. Fit eye bolt (key 35) into the upper spring seat (key 73)
threaded hole.
7. Carefully remove the trim system from the sleeve guide
(key 61) using the eye bolts (key 35).
8. Remove socket head cap screws (key 33) and lock
washers (key 32).
9. Lift off the disk retainer (key 31) and disk holder assembly
(key 30).
10. Remove the O-ring (key 29). Inspect the O-ring for
damage or wear, replace if necessary. Lightly lubricate
O-ring before placing the sleeve adaptor (key 27).
11. Place disk holder assembly (key 30) onto disk retainer
(key 31).
Table 3. Torque Specifications
PART NAME
TORQUE SPECIFICATIONS
Body Size
NPS 1 / DN 25
NPS 2 / DN 50
NPS 3 / DN 80
NPS 4 / DN 100
foot-pound
N•m
foot-pound
N•m
foot-pound
N•m
foot-pound
N•m
Indicator Fitting or Plug (key 141)
10 to 30
14 to 41
10 to 30
14 to 41
10 to 30
14 to 41
10 to 30
14 to 41
Stud Nuts (key 26)
45 to 50
61 to 68
45 to 50
61 to 68
80 to 95
108 to 129
- - - -
Socket Head Cap Screws (key 16)
50 to 70
(1)
5.6 to 7.9
50 to 70
(1)
6 to 7.9
50 to 70
(1)
6.2 to 7.9
100 to 115
(1)
11 to 13
Stud Bolts (key 24)
50 to 70
68 to 95
50 to 70
68 to 75
100 to 120
136 to 163
- - - -
Cap Screws (key 21)
50 to 55
68 to 75
130 to 150
176 to 203
250 to 270
339 to 366
280 to 310
380 to 420
Cap Screws (key 6)
50 to 60
68 to 81
50 to 60
68 to 81
70 to 95
95 to 129
140 to 155
190 to 210
Socket Head Cap Screws (key 33)
30 to 40
(1)
3.4 to 4.5
50 to 60
(1)
5.6 to 6.8
80 to 100
(1)
9 to 11
80 to 100
(1)
9 to 11
Smart Screws (key 68)
- - - -
- - - -
- - - -
31 to 40
(1)
3.5 to 4.5
Socket Head Cap Screws (key 74)
- - - -
- - - -
- - - -
26 to 35
(1)
2.9 to 4
Cap Screws (key 77)
- - - -
- - - -
- - - -
90 to 110
122 to 149
Sleeve Guide (key 61)
- - - -
- - - -
- - - -
130 to 140
176 to 190
Cap Screw (key 154)
16
(1)
1.8
50
(1)
5.6
10
14
2.9 to 3.5
3.9 to 4.7
Stem Nut (key 151)
32
43
32
43
45
61
45 to 50
61 to 68
Stem Nut (key 155)
30
41
- - - -
- - - -
- - - -
Hex Nut (key 152)
- - - -
40
54
60
81
45 to 50
61 to 68
1. Torque specifications are given in inch-pounds.
