Re-Machining The Disc Seat - GE Baker Hughes 2900-40 Series Maintenance Manual

XIV. Maintenance Instructions (Cont.)
3. Take the following steps to re-machine the metal-to-
metal nozzle (Figure 18a and Table 2):
a. Make light cuts across the surface L at 5º until the
damaged areas are removed. Turn to the smoothest
possible finish.
Figure 22: Nozzle Positioned in a Jaw
b. The nozzle is now ready for lapping.
c. When the minimum dimension D from Table 2 is
reached, discard the nozzle.
4. Take the following steps to re-machine the O-Ring seat
seal (Figure 18b and Table 2):
a. Make light cuts across surface A (45º) until the
damaged areas are removed. Turn to the smoothest
possible finish.
b. Re-machine radius R.
c. The nozzle is now ready for lapping.
d. When the minimum dimension H is reached, discard
the nozzle.
© 2019 Baker Hughes, a GE company. All Rights Reserved.
I. Re-Machining the Disc Seat
Take the following steps to machine the standard disc seating
surface (Figure 23):
Figure 23: Standard Disc Seating Surface
1. Grip the disc in a four-jaw independent chuck (or collet, if
appropriate), using a piece of soft material such as copper
or fiber between the jaws and the disc as shown at A.
2. True up the disc so that the surface marked B and C run
true within .001" (0.03 mm), TIR.
3. Make light cuts across the seating surface L until
damaged areas are removed. Turn to the smoothest
possible finish.
4. The disc is now ready for lapping.
5. Discard the disc if the minimum dimension N or T (Figure
24, Table 5) is reached. Do not reestablish surface C.
ATTENTION!!
Do not remachine a Thermodisc or O-Ring Retainer.
Consolidated 2900-40 Series POSRV Maintenance Manual | 35
Chuck Jaw
A
Disc
90°
C
L
B