Flowserve 1888 Double-Disc Gate Valve - Manual (Page 12)

12
9.0 MAINTENANCE INSTRUCTIONS
9.1 The following instructions cover the disassembly and reassembly of a Series 1888 double-disc gate valve.
Typical valve configuration is shown in Figure 1 (see Section 12).
CAUTION
CHECK ONE PRESSURE: IF LINE IS STILL UNDER PRESSURE, VENT
BEFORE VALVE DISASSEMBLY IS STARTED
9.1.1 Disassembly
Extreme care should be taken to avoid possible damage to the valve’s moving parts. It is recommended
that valves be placed in a vertical position for disassembly, if possible. For valves inline, take special care
not to drop or damage any of the internals.
Ensure that the stem and disc pack do not separate when removed. They are removed as one unit until
both are adequately supported. Failure to remove as one unit could cause damage to the discs.
After removal from the valve, care should be taken to protect the seating surface of the discs from damage.
The discs should be placed in a clean area until ready to replace in the valve. THE SLIGHTEST NICK OR
SCRATCH ON A SEATING SURFACE COULD PREVENT COMPLETE SHUT-OFF AND NECESSITATE
EXTENSIVE REWORK OR REPLACEMENT.
(a) Place the valve in the closed position without wedging the discs into position by closing the valve
and then opening about one-half of a revolution of the tee handle.
(b) Remove the handwheel nut (240) from the yoke sleeve (017). Remove the tee handle (175) and
thrust washer (147) from the yoke sleeve (017) by sliding it up and over the yoke sleeve.
(c) Remove the tee handle (175) and thrust washer (147) from the yoke sleeve (017) by sliding it up
and over the yoke sleeve.
(d) Remove the yoke clamp nut (233), allowing removal of the yoke capscrew (217).
(e) Rotate the yoke (011) in a counterclockwise direction to remove from the body (001) and slide it
up and over the yoke sleeve.
(f) Turn the yoke sleeve (017) off the stem (025).
1888-lb. Double-Disc Gate Valve FCD ADENIM0001-00