16 | BHGE
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XII. Disassembly of the 13900 POSRV
A. Disassembly of Pilot from Main Valve
DANGER
Many pressure vessels that are protected by Consolidated Safety Relief Valves contain
dangerous materials. Decontaminate and clean the valve inlet and outlet and all external
surfaces in accordance with the cleaning and decontaminating recommendations in the
appropriate Material Safety Data Sheet.
With reference to Figures 2 and 3 and their Nomenclature, proceed in accordance with
the following steps. If a discharge tube is not supplied, omit steps 1 and 2.
1. With an appropriate tool and counterclockwise rotation, remove Tube Fittings
(43A) from Main Valve Base (1) and Bonnet (29A)
2. Remove Discharge Tube (43B) from pilot outlet by pushing tube into main valve base.
3. Remove six Bonnet Stud Nuts (45) from Pilot Flange (21) and raise pilot valve and
flange from Bonnet Studs (44).
4. Remove pilot valve Base Gasket (52)
5. Remove Sensing Unit (17) and also the Lower Gasket (52)
B. Disassembly of Pilot Valve
Refer to Figure 3 for the following: Remove cotter pin and Lever Pin (38) and Lifting Lever
(33). Unscrew the Cap Lockscrew (39) and remove the Cap (37). Remove the Cap Release
Nut (35) and Release Locknut (36).
Removing Adjusting Ring Pin (27) and Gasket (53), observing through the outlet of the valve,
rotate Adjusting Ring (28) counterclockwise one notch at a time until contact is made with
the Disc (42A). Record the number of notches from original position to contact with disc.
Measure the distance from the top of the Compression Screw (40) to the top of the Pilot
Bonnet (29A) with a calliper or depth micrometer and record this information to restore
compression during assembly. Loosen the Locknut (34) and turn the Compression Screw
(40) counterclockwise until compression is removed from spring.
Place the pilot valve with its inlet flange on the main valve Bonnet (19) and secure in
place with nuts to prevent the Pilot Base (20) from rotating.
Using a suitable wrench, break loose the pilot bonnet and rotate counterclockwise to
remove the bonnet from the pilot base. Lift the pilot bonnet vertically from its base and set
aside, Remove the spring assembly, disc assembly, and spindle from pilot base.
Remove Disc Assembly (42A, 42B, 42C, 42D) from the spindle by lifting on the Spindle
(31) and engaging the drop out threads in disc. Rotate the spindle counterclockwise until
the spindle and disc assembly separate.
C. Pilot Valve Cleaning
DANGER
Follow recommendations for safe handling in the solvent's Material Safety Data Sheet.
13900 Series Safety Relief Valve internal parts may be cleaned with industrial solvents,
cleaning solutions and wire brushes. 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.
It is not recommended to "sand blast" Internal parts as it can reduce the dimensions of
the parts. The base, bonnet and cap castings may be sand blasted with care not to erode
or damage machined surfaces.
Do not remove bolts if
pressure in line, as this
will result in severe
personal injury or death.
Decontaminate or clean
if necessary before
pretesting or disassembly.
Safety and environmental
precautions must be taken
for the decontamination or
cleaning method used.
Follow recommendations
for safe handling in the
solvent's Material Safety
Data Sheet.
