Flowserve SMB Series Electric Actuators - Manual (Page 88)

SMB Series/SB Series Installation and Maintenance FCD LMENIM1401-04-AQ – 01/15
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8.3 SB-1
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-1 actuator is a basic SMB-1 actuator with the housing cover, drive sleeve, and locknut
modified to provide spring compression to the stem nut. The disassembly/assembly procedure for
the SMB-0 is applicable (Section 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.
8.3.1 SB-1 Disassembly/Stem Nut Removal
Piece numbers refer to Figure 8.3.
1. Remove the Spring Housing (piece #159).
2. Remove the Spring Housing Adapter (piece #156).
3. Remove the Thrust Spring Bearing Cartridge (piece #151). The Belleville Springs (piece #153),
Seal Bushings (piece #160) and Belleville Spring Shim (piece #154) will come off with the Thrust
Spring Bearing Cartridge.
4. Remove the Thrust Sleeve (piece #147). Be careful not to loosen or damage the Quad Ring (piece
#150). The Bearing (piece #146) will come out with the Thrust Sleeve (piece #147).
5. Remove the Bearing Retainer (piece #155). Remove the Drive Sleeve (piece #11) 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, the Stem Nut (piece #20) is accessible. If the actuator is on the
valve, bolt the Bearing Retainer (piece #155) to the housing using two 5 ⁄
8
" x 11 UNC x11/4" long
bolts.
a. Place the actuator in hand operation.
b. Rotate the Handwheel in the direction to effect a downward movement of the stem—usually
the close direction. The Stem Nut will climb up the stem until it clears its splines.
c. Rotate the Stem Nut off the stem.
8.3.2 SB-1 Reassembly/Stem Nut Installation
Piece numbers refer to Figure 8.3.
1. Replace the Stem Nut (piece #20).
a. If the actuator is not on the valve, the Stem Nut will drop in the Drive Sleeve (piece #11) until it
bottoms out on the shoulder in the bottom of the Drive Sleeve. Ensure splines are engaged.