Flowserve SMB Series Electric Actuators - Manual (Page 85)

85
SMB Series/SB Series Installation and Maintenance FCD LMENIM1401-04-AQ – 01/15
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4. 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 5.
5. If the actuator is not on the valve, the Stem Nut (piece #20) is accessible. If the actuator is on the
valve, bolt a support bar across the top of the actuator housing to hold the Thrust Bearing (piece
#77 and #78) in place.
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.
8.2.2 SB-0 Reassembly/Stem Nut Installation
Piece numbers refer to Figure 8.2.
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.
b. If the actuator is mounted on the valve, thread the Stem Nut (piece #20) down the stem until
the spines hit. Put the actuator in manual operation. Rotate the Handwheel in the direction to
move the stem upward—usually the open direction. The Stem Nut will lower as the Handwheel
turns, until it bottoms out on the shoulder in the Drive Sleeve bottom and the stem starts to
move up.
2. Replace the Thrust Sleeve (piece #107) and the Bearing (piece #116). Ensure O-Rings (pieces
#117 and 94) are properly installed.
NOTE: Ensure Thrust Sleeve engages the splines on the top of the Stem Nut (piece #20)—Thrust
Sleeve will not rotate if not engaged properly.
3. Clean Housing (piece #2), flange, and mounting flange of the Spring Housing (piece #3).
4. Install Spring Housing (piece #3) without any gasket. Measure the gap between the Spring
Housing (piece #3) and the Housing (piece #2).
5. Remove Spring Housing (piece #3). Install a Gasket (piece #66) between Housing and Spring
Housing.
NOTE: The Gasket thickness should be the same as the gap measured in Step 4, plus an allowance
for the compressibility of the gasket material used. If an exact gasket thickness can not be obtained,
use the next higher thickness gasket available.
6. Replace the Thrust Sleeve Bearing Cartridge (piece #106) along with the Belleville Springs (piece
#109—four washers), and the Belleville Spring Shim (piece #108).
7. Inspect to ensure O-Ring (piece #118) is properly installed in the Spring Housing (piece #3).
Install Spring Housing.