Flowserve SMB Series Electric Actuators - Manual (Page 91)

91
SMB Series/SB Series Installation and Maintenance FCD LMENIM1401-04-AQ – 01/15
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8.4 SB-2
c WARNING: See Section 4.1 and 4.2 on Safety Precautions and Safety Practices before
proceeding with disassembly.
c WARNING: Extreme caution should be used in the disassembly and reassembly of the spring
compensator assembly. The compensator springs may be compressed (under load) even though
the line pressure has been removed from the valve and power is disconnected. Be sure that the
spring compensator indicator in the Spring Housing points to zero before beginning disassembly.
Remove the Spring Housing bolts by turning each bolt in order around the housing no more than
1/4 turn at a time.
The SB-2 actuator is a basic SMB-2 actuator with the housing cover, drive sleeve, and locknut modi-
fied to provide spring compression to the stem nut. The disassembly/assembly procedure for the
SMB-2 is applicable (Sections 7.3.1, SMB-0, 1, 2, 3 and 4 Disassembly and Section 7.3.3, SMB-0,
1, 2, 3 and 4 Reassembly), with the following procedures replacing Step 11 and stem nut removal
procedure.
8.4.1 SB-2 Disassembly/Stem Nut Removal
Piece numbers refer to Figure 8.4.
1. Remove Spring Housing Cover (piece #161).
2. Remove Spring Cartridge (piece #173), complete with Belleville Springs (piece #179), Thrust
Washers (piece #178), Thrust Limit Sleeve (piece #199), and Spring Retainer Cap (piece #180).
NOTE: The spring assembly should not be disassembled unless absolutely necessary.
To disassemble the compensator spring cartridge:
a. Remove the Spring Retainer Cap (piece #180). Be careful to remove the set screws securing
the Spring Retainer Cap to the Spring Cartridge before trying to remove locknut.
b. Lift off the Thrust Washer (piece #178), the Belleville Springs (piece #179), and the Thrust
Limit Sleeve (piece #199).
To reassemble the Spring Cartridge:
a. Position the Belleville Springs (piece #179) between the two Thrust Washers (piece #178) as
shown in Figure 8.4.
b. Thread Spring Retainer Cap (piece #180) onto the Spring Cartridge (piece #173) until it hits
the shoulder on the cartridge.
c. Reinstall set screws or drill and tap for new set screw locations.
3. Remove the Thrust Sleeve (piece #168), complete with the Bearing Cup (piece #169) and the
Bearing Cone (piece #170).
4. Read Step 6. Remove the Spring Housing (piece #163).
5. Remove the Drive Sleeve in accordance with Step 12 of Section 7.3.1, SMB-0, 1, 2, 3 and 4
Disassembly. If only the Stem Nut (piece #20) is to be removed, see Step 6.
6. If the actuator is not on the valve, lift the Stem Nut (piece #20) directly from the actuator. If the
actuator is on the valve, bolt a support bar across the top of the actuator Housing to hold the
Bearing Cone (piece #77) and the Bearing Cup (piece #78) in place.