2900-40 Series Posrv Options; Backflow Preventer; Disassembly Instructions; Cleaning - GE Baker Hughes 2900-40 Series Maintenance Manual

XXII. 2900-40 Series POSRV Options
A. Backflow Preventer
When the pilot operated safety relief valve is not vented
directly to atmosphere, it is possible to build up backpressure
in the discharge line. This is typical in situations where several
valves manifold into a common discharge header. Should the
discharge line pressure exceed the valve inlet pressure, it
could cause the disc to lift and allow reverse flow through the
main valve. This situation can be eliminated through the use of
the Backflow Preventer.
Back ow
Preventer
Field Test
Connection
Figure 42: Field Test Connection /
Backflow Preventer Option
Note: Item #23 in Figures 3 is the same Field Test Connection shown
here in Figure 42. Shuttle Base (23c) can be square or octagon
bar stock.
A.1 Disassembly Instructions
1. Remove Shuttle Plug from Shuttle Base by unscrewing
counterclockwise.
2. Remove Shuttle Ball, Tube Filter, and O-Rings and discard.
A.2 Cleaning
1. If required, clean parts to remove all rust, burrs, scale,
organic matter, and loose particles. Parts are to be free of
any oil or grease except for lubrication as specified in this
instruction.
2. Cleaning agents used shall be such that effective cleaning
is assured without injuring the surface finishes or material
properties of the part.
© 2019 Baker Hughes, a GE company. All Rights Reserved.
3. Acceptable cleaning agents include demineralized water,
nonphosphate detergent, acetone, and isopropyl alcohol.
Parts must be blown dry or wiped dry after cleaning.
4. If you are using cleaning solvents, take precautions
to protect yourself from potential danger from
breathing fumes, chemical burns, or explosion. See the
solvent's Material Safety Data Sheet for safe handling
recommendations and equipment.
5. It is not recommended to "sand blast" internal parts as it
can reduce the dimensions of the parts.
A.3 Parts Inspection
1. Shuttle Base: Galling or excessive wear on the threads.
Check for any corrosion or pitting.
2. Shuttle Plug: Galling or excessive wear on the threads.
Check for any corrosion or pitting.
A.4 Reassembly Instructions
Lubricate O-Rings with silicone grease BHGE P/N SP505.
1. Assembly of Field Test Connection / Backflow Preventer
Assembly.
Back ow
Preventer
a. Insert one of the Small O-Rings into the Shuttle Base
b. Insert the Tube Filter into the Shuttle Base.
c. Insert Shuttle Ball inside of Tube Filter.
d. Insert the other Small O-Ring into the Shuttle Plug
e. Thread Shuttle Plug into Shuttle Base, wrench tighten.
23d
counter bore.
counter bore. Install Larger O-Ring into groove located
on OD of Shuttle Plug.
23b 23a 23e
Ref. No
23a
23b
23c
23d
23e
Figure 43: Backflow Preventer Option
Consolidated 2900-40 Series POSRV Maintenance Manual | 55
23b 23c
Part
Shuttle Ball
O-Ring
Shuttle Base
Shuttle Plug
Tube Filter