Disassembly; Precautions During Reassembly - Yoshitake GP-2000 Installation & Operation Manual

(6)Remove condensate completely from the line, and close the stop valves before and
after the valve when not using it for long periods of times.
※Rust generated in the valves and lines may cause malfunction.
(7)In case of no operation for a long period of time, perform operating exam before start
operation again.
※Request the treatment to specialized dealer or manufacture in case of any problems.

8.3 Disassembly

Be sure that the stop valves at inlet and outlet side of pressure reducing valve is closed and all internal
pressure and condensate have discharged before disassembling the valve.
(1) Pilot valve
1. Slightly loosen lock nut [28] and turn adjusting screw [27] counterclockwise to release spring
[24] (no compression).
2. Remove bolt [37] of spring chamber [3]. Remove the spring chamber, spring, top spring plate
[25], bottom spring plate [26], and pilot diaphragm [23].
3. Remove pilot valve seat [18] (hexagonal section of the center of pilot body [2]) using a ring
spanner or socket wrench (nominal size 22), and remove the entire pilot valve assembly.
(2) Main valve (15-125A)
1. Remove pipe A [34] at joint A [30] or tee [33].
2. For nominal sizes 15A to 40A, remove bolt [38] of pilot body [2]. Dismount the pilot body from the
body [1]. And remove spring plate [14], screen [15], main valve spring [13], and main valve [6].
For nominal sizes 50A to 125A, remove bolt [44] of spacer [54] and remove the spacer from the
main body [1], main valve spring [13], and entire main valve ([6], [9], [50], and [51]) (for nominal
size 50A, main valve spring [13], and main valve [6]).
(3) Main diaphragm
1. Remove pipe C [36] at tee [33].
2. Remove bolt [41] of bottom dia. case [5]. Dismount the bottom dia. case, main diaphragm
[12], retainer [11], and spindle [9] (adapter [52] and retainer [11] for nominal sizes 65A to 125
A).
8.4 Precautions during disassembly
Caution
(1) Check that there is no damage and scratches on the main valve, main valve seat, pilot
valve, and pilot valve seat.
※Any scratches at sealing surface lead to increase in secondary pressure. When any
scratches are identified at main valve and seat, polish them away. And, change the
parts if scratches still exist after polishing. Also, in case any scratches are identified
at pilot valve and pilot valve seat, change into pilot valve assembly.
(2) Move the sliding section (pilot valve, piston, etc.) two to three times and confirm they
move smoothly.
※If the sliding parts do not move correctly, it may cause failure problems. (Working not
correctly).
(3) Replace gaskets with new ones when reassembling.
※If the gasket is used for a long time, it may cause steam leakage problem.
(4) Assemble in the reverse order of Disassembly. And tighten the bolts evenly.
※Assemble the valve due to the order. Failure to do so may lead to not assemble
correctly. And if the hexagon bolts are not screwed correctly, it may cause steam
leakage problem.
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