H. Re-Machining Nozzle Seats
1. Remove the nozzle from the valve to be
remachined. If it cannot be removed from the
base, re-machine it inside the base.
2.
Take the following steps to setup the lathe and
nozzle:
a.
Grip the nozzle 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 nozzle as shown
at A (Figure 39).
b. True up the nozzle so that the surfaces
marked B and C run true within .001” (0.03
mm) on indicator (Figure 39).
3.
Take the following steps to re-machine the
metal-to-metal nozzle (Figure 34a 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.
b.
The nozzle is now ready for lapping.
c. When the minimum dimension H is reached,
discard the nozzle.
4.
Take the following steps to re-machine the
O-Ring seat seal (Figure 34b 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.
I. Re-Machining the Disc Seat
Take the following steps to machine the standard
disc seating surface (Figure 40):
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 41, Table 5) is reached. Do not
reestablish surface C.
ATTENTION!
Do not remachine a
Thermodisc
™
or O-Ring Retainer.
Figure 39: Nozzle Positioned in a Jaw
C
90°
L
B
Disc
Chuck Jaw
A
Figure 40: Standard Disc Seating Surface
XIV. Maintenance Instructions (Cont.)
Consolidated 2900 Series Generation II POSRV Instruction Manual
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