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Baker Hughes
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3. Polishing or Finish Lapping:
Wipe off all used compound from the bushing or
disc. Then use a flat, reconditioned ring lap, and
light coating of Kwik-Ak-Shun™ 1000 Grit Grinding
Compound to lap the seat. After lapping the seat
for some time, wipe off all grinding compound from
the ring lap (do not wipe off the compound on the
bushing or disc seat). Using only the compound
remaining on the seat, and the clean ring lap,
continue to lap until it becomes difficult to move the
ring lap on the seat. Again, wipe off the grinding
compound from the ring lap only, and using the
remaining compound on the seat continue to lap.
The seating surface will become mirror like as the
grinding compound is further broken down. Inspect
the seat for cuts and scratches, repeat procedures
as necessary to eliminate damage.
Once the seat surface is flat, clear and mirror-like, wipe
all traces of grinding compound from the part and begin
reconditioning the other seat.
Note: Do not place the disc in a vice to accomplish
lapping procedures, as damage can occur to
disc surfaces and distortion to the seating
surface.
D. Reconditioning a Ring Lap
To recondition a ring lap, use Clover 1-A Compound on
the lapping plate, and move the ring lap in a “figure 8”
motion as shown in Figure 5. Continue lapping until all
indications of wear (on both sides), are removed from
the ring lap and a uniform grey surface is achieved. The
ring lap is ready to use on the next valve. A lap that is flat
within one light band is considered satisfactory for use.
Information on the monochromatic light and optical flat
is available upon request from the Baker Hughes Field
Service Department.
A
C
45
0
A
B
Figure 6: Spindle Check Stand
Table 2: Spindle Critical Dimensions
Orifice
C max.
in.
mm
H
.004
0.10
J
.004
0.10
K
.007
0.18
L
.007
0.18
M
.007
0.18
N
.007
0.18
P
.007
0.18
Q
.007
0.18
Lapping Plate
Ring Lap
Figure 5
XI. Maintenance Instructions (Cont’d)
