B. Dirty Service Option (Contd.)
B.1 Disassembly Instructions
1. The Dirty Service Option consists of:
1 – Insert Assembly
1 – Dirty Service Insert
1 – O-Ring (Dirty Service Insert)
1 – Regulator
2. The Insert Assembly consists of:
1 – Insert Top
1 – Insert Bottom
1 – Spring Seal (Insert)
1 – O-Ring (Insert)
3. Remove Dirty Service Insert and discard O-Ring
(Dirty Service Insert).
4. Remove Insert Assembly from the Dirty Service
Insert with tool #4995401. Remove and discard
the O-Ring (Insert) on the bottom of the Insert
Assembly. Disassemble Insert Assembly by
removing the Insert Bottom from the Insert Top.
Discard Spring Seal (Insert).
5. Return to Disassembly Instructions for pilot
(Section XVII).
B.2 Cleaning
1. 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.
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. Do not “sand blast” internal parts as it can reduce
the dimensions of the parts.
B.3 Parts Inspection
1. Insert Top: Galling or excessive wear on the inside
diameter that guides the Main Piston. Check for
any corrosion or pitting. Also, check for galling of
threads.
2. Insert Bottom: Galling or excessive wear on the
inside diameter that guides the Main Piston. Check
for any corrosion or pitting.
B.4 Reassembly Instructions
Making the Insert Assembly for Dirty Service Option:
1. Press Spring Seal (Insert) into groove on the Insert
Bottom. Make sure spring is facing upwards.
2. Install Insert Top over Insert Bottom with the seal
side going in first.
3. Lightly lubricate O-Ring groove now formed by the
two insert parts. This lubrication is used to hold the
O-Ring (Insert) in place when it is being inserted
into Dirty Service Insert.
4. Place O-Ring (Insert) into groove.
5. The Insert Assembly is threaded into the Dirty
Service Insert. Tighten assembly wrench tight. Make
sure milled slot is facing up.
6. Install O-Ring (Top-Plate) onto groove in Pilot Base.
7. Install Dirty Service Insert Assembly on top of
Pilot Base with inlet port facing opposite of vent
port on Pilot Base. Then install Main Piston / Top
Plate Assembly onto Base/Dirty Insert by inserting
small diameter end of Main Piston through Insert
Assemblies.
50a
50g
50c
50d
50e
50b
50f
Ref. No.
Part
50a
Dirty Service Insert
50b
Insert Top
50c
Insert Bottom
50d
O-Ring (Insert)
50e
Spring Seal (Insert)
50f
O-Ring (Dirty Service Insert)
50g
Regulator
Figure 66: Dirty Service Parts
XXII. 2900 Series POSRV Options (Contd.)
76 | BHGE
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