C. Assembly Procedure with O-Ring
Seats
1. If the valve Nozzle was removed, apply thread
lubricant to the nozzle threads before reinstalling in
the Base. Insert it into the inlet flange of the Base,
and torque to the correct value listed in Table 9.
2. Assemble the disc/disc holder as follows:
a. For disc sizes “D” thru “J”, reassemble the Disc
Holder using a new O-Ring, O-Ring Retainer,
and new Lock Screw(s). Refer to Table 10 for
the proper torque. These Disc Holders are
ready for the next step.
b. For disc sizes “K” thru “W”, reassemble the
Disc using a new O-Ring, O-Ring Retainer, and
new Lock Screws. Refer to Table 10 for the
proper torque.
(i) Prior to assembly of the Disc into the Disc
Holder, remove the Disc Retainer from the
back of the Disc. Use 1000 grit grinding
compound on the bearing surface to grind
the Disc into the Disc Holder to properly
establish the bearing surface.
(ii) Place the Disc Retainer into the groove
in the disc. The Disc with the Disc Retainer
should “snap” into the Disc Holder pocket
with moderate finger or hand force. Do
not use excessive force to assemble these
parts. Be sure that the Disc is free to
“wobble” after it is in place. For V and W
orifice discs, place Disc into Disc Holder
and secure Disc Retaining Bolts.
3. Set the Disc Holder (disc side down), on the work
surface. Place a small amount of 1000 grit grinding
compound onto the ball end of the Main Valve
Piston and place it in the disc holder pocket. Turn
the Main Valve Piston clockwise, and then counter
clockwise, to seat the Main Valve Piston. Clean all
grinding compound from parts.
4. a. For bellows valves “D” through “U”, place a
new Bellows Gasket on the Disc Holder. Thread
the Bellows, finger-tight, down to the Gasket
on the Disc Holder. Use a pin spanner wrench, or
special cable type wrench to turn the Bellows
Ring down until a pressure tight joint is obtained.
b. For bellows valves “V” and “W”, place a new
Bellows Gasket on the Disc Holder. Bolt down
using proper torque as found in the assembly
instructions.
c. For Spring Assist valves, place the Spring down
onto the Disc Holder.
5. a. For D through U orifice valves:
Place the Guide over the Disc Holder. (DO NOT
DROP.) If Bellows is present, the weight of the Guide
will slightly compress the Bellows.
b. For V and W orifice valves:
Install guide rings into the grooves located inside
the guide ID. Make sure the space where the upper
and lower guide ring ends meet is positioned 180°
apart. Mark both the guide and disc holder at the
point where the bottom guide ring ends meet. This
mark must be faced 180° away from the outlet
when the assembly is place into the valve. Gently
lower the guide down onto the disc holder ensuring
that guide rings remain in their respective groove.
6. Place the Guide Gasket in the Base.
7. Install disc guide assembly. Use the same lifting
tools (see Figure 21 and Figure 22) as was used
during disassembly, then carefully lower it into
the Base.
On “V” and “W” sizes, use the same lifting lugs as
were used during disassembly.
8. Using a small amount of Silicone Grease supplied
with soft goods replacement kit, rub a small
amount on the seals and O-rings prior to assembly.
9. Take the Main Valve Piston and measure and cut
diagonally the proper length of Guide Ring material
to fit in the groove of the Main Valve Piston. Allow
1/16 of an inch gap between the ends for proper fit.
10. For Teflon seals make sure of the integrity of the
Teflon seal and seal spring. Install Disc Seal on Disc
outside diameter on the opposite end of the disc
seat as shown in Figure 39.
XVI. Reassembly of the 2900 Main Valve (Contd.)
Main Valve Piston
Main Valve
Piston O-Ring
Guide Ring
Figure 39: Main Valve Piston
46 | BHGE
© 2018 Baker Hughes, a GE company. All Rights Reserved.
