9. Place Spring Washers on the ends of the Spring.
There is not a top or bottom Spring Washer unless
the Lifting Lever option is installed.
10. If pilot has Lifting Lever Option:
a. Place Spring over Lifting Stem and place on
Bottom Spring Washer.
b. Place Top Spring Washer on top of Spring and
then place the entire assembly on top of Pilot
Base assembly ensuring that the spherical
radius located on the Bottom Spring Washer
engages with spherical nose on Main Piston.
11. Install the Bonnet over the Spring and Spring
Washer Assembly. Thread the Bonnet onto the
Top Plate. Tighten wrench tight. Install and tighten
Set Screw.
12. Turn Compression Screw clockwise until
dimension has been reached that was noted
during disassembly.
13. Tighten Compression Screw Lock Nut wrench tight.
14. For Lifting Lever Option, reinstall Release Nut and
Release Lock Nut onto Lifting Stem. Turn clockwise
until it matches the dimension noted during
disassembly.
a. Install Filter Plug into Bonnet vent hole
(if removed).
15. Install Pipe Plug (Pilot Valve) in port above vent
hole.
16. Refer to Field Test Connection / Backflow Preventer
Option for reassembly of Field Test Connection
17. Making The Modulator Piston Assembly:
a. Install Spring Seal (Piston Top) into groove
on Modulator Piston Top. Be sure to have the
spring in the seal facing up.
b. Install O-Ring (Modulator Seat) into groove
on Modulator Piston Bottom.
c. Turn Modulator Piston Bottom over and
place O-Ring (Modulator Piston Bottom) into
inner groove.
d. Install Spring Seal (Piston Bottom) onto
Modulator Piston Bottom in outer groove.
Make sure spring is facing down.
e. Insert Modulator Piston Top into Modulator
Piston Bottom through the side with the O-Ring
(Modulator Piston Bottom) and the Spring Seal
(Piston Bottom).
f. Turn assembly over and install O-Ring Retainer.
The chamfered outside diameter goes in first.
g. Thread Lock Screw through the O-Ring Retainer
into Modulator Piston Top. Tighten 40 ± 5 in-lbs
(4.5 ± 0.6 N-m).
h. Final Modulator Piston Assembly is shown in
Figure 52.
15. Lubricate Spring Seals before inserting into
Modulator Base.
16. Insert Modulator Piston Assembly into Modulator
Base with the Modulator Piston Top going in first.
Push piston in with thumbs until it stops. There
will be some resistance due to the Spring Seals
compressing to fit into the bore of the Modulator
Base. If necessary for installation, insert the proper
wrench into the Lock Screw. Lightly tapping the
wrench with a hammer will force the Modulator
Piston Assembly into the Modulator base.
17. Install both O-Rings (Modulator Stop) into grooves
on Modulator Piston Stop.
18. Insert Modulator Stop into Modulator Base with
the seat going in first. Make sure the side hole
in the Modulator Stop is facing towards the flat
side of the Modulator Base.
19. Thread the Cap Screws (Modulator) through the
Modulator Stop into the Modulator Base. Tighten to
365 ± 30 in-lbs (41.2±3.4 N-m).
20. Do not install Modulator Assembly at this time.
Spring Seal
(Piston Top)
Spring Seal
(Piston Bottom)
Modulator
Piston Bottom
O-Ring
(Modulator Seat)
Lock Screw
O-Ring Retainer
Modulator
Piston Top
Figure 52: Modulator Piston Assembly
XIX. Reassembly of Pilot Valve (Contd.)
Consolidated 2900 Series POSRV Maintenance Manual
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