Consolidated 1811 Series Safety Valve Instruction Manual
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© 2020 Baker Hughes Company. All rights reserved.
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 7. 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
Consolidated Field Service Department.
Lapping Plate
Ring Lap
Figure 7
XI. Maintenance Instructions (Cont.)
C. Lapping Procedures
1. General:
While the finer points of lapping may be considered
a mechanical art, it is possible for the average
mechanic to produce satisfactory results with some
practice. No effort has been made in this manual
to establish an exact procedure to cover each and
every case because different people can achieve
the same results using their own techniques.
The following materials will be of assistance when
lapping bushing and/or disc seats:
a. Two ring laps per valve
b. 1-A Clover Grinding Compound
c. 1000 grit Kwik-Ak-Shun Grinding Compound
d. Lint free wipers for cleaning
2. Lapping the seat bushing or Disc Seat:
Before lapping the seat bushing and disc, use a
fine grade sandpaper to lightly break the inner
edge and outer edge of the bushing and disc seats.
This chamfer should not exceed .002” (.05mm). If
the seating surfaces require extensive lapping or
reconditioning, machining should be considered
prior to lapping. See Inspection Section XII.B. for
criteria. Cover one flat surface of a ring lap with
a thin coating of Clover 1-A Grinding Compound
and gently set the lap on the seat surface. Thick
coatings tend to round off edges of the seat.
Lap using a slight oscillating motion in various
directions. Control the motion of the lap to prevent
the inside edge or outside edge of the lap from
running off the seating surface, as this may cause
the seat to become scratched or uneven.
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.
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.
