Flowserve SMB Series Electric Actuators - Manual (Page 99)

99
SMB Series/SB Series Installation and Maintenance FCD LMENIM1401-04-AQ – 01/15
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8.6 SB-4
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-4 actuator is a basic SMB-4 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-4 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.
8.6.1 SB-4 Disassembly/Stem Nut Removal
Piece numbers refer to Figure 8.6.
1. Remove the Spring Housing (piece #163).
2. Remove the Thrust Washer (piece #178).
3. Remove the Spring Cartridge Assembly including the Spring Cartridge (piece #173), Belleville
Spring (piece #179), and Spring Cartridge Cover (piece #180).
4. Remove the Bearing Cartridge (piece #168). Bearing Cone (piece #169) and Bearing Cup (piece
#170) will come out with the Bearing Cartridge.
5. Remove the Housing Cover Cartridge (piece #155).
6. 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 7.
7. If the actuator is not on the valve, the Stem Nut (piece #20) is accessible. If the actuator is on the
valve, bolt the Housing Cover Cartridge (piece #155) to the Housing (piece #2) using two 1"-8
UNC x 2.5" 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.
8.6.2 SB-4 Reassembly/Stem Nut Installation
Piece numbers refer to Figure 8.6.
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 of the Drive Sleeve. Ensure splines are engaged.
b. If the actuator is mounted on the valve, thread the Stem Nut (piece #20) down the stem until
the splines hit. Put the actuator in manual operation. Rotate the Handwheel in the direction to