Flowserve 608 Series Ball Valve - Manual (Page 2)

c. Care must also be taken when handling
graphite thrust bearing, stem seal, or seat back
seal. These parts can be easily damaged by
squeezing the O.D. of the seal. Parts are to be
handled on the flat surfaces rather than the O.D.
d. The ball used in valves with “A” and “G” (filled
metal) seats is round to special tolerances. To
ensure proper contact with the seat, do not drop,
dent or scratch the ball during handling. These
balls also have an anti-galling coating. DO NOT
use uncoated balls with filled metal seats.
2.0 OPERATION
1. The operation consists of turning the handle
and/or stem 1/4 turn clockwise to close and 1/4
turn counter-clockwise to open. When the handle
and/or stem flats are in line with the pipeline, the
valve is open. These valves may also be
automated.
2. These valves will provide bubble-tight shut-off
when used in accordance with Worcester’s
published pressure/temperature chart. Valves with
“G” seats meet the leakage rates of ANSI B16.104
Class VI.
3. It is not good practice to leave a ball valve
partly open (throttling operation) without
knowledge of the pressure drop and flow at
that position.
4. As shipped from the factory, all valves (except
oxygen prepared (V20, V33 or prefix code “X”),
and valves with V38 or V6 options) contain a
silicone-based lubricant. This is for break-in
purposes, and may be removed if it is
objectionable for a particular application by
disassembling and solvent washing. Lacquer
thinner will remove the lubricant. “A” or “G” (filled
metal) seated valves should not be operated
without a break-in lubricant.
5. Media which can solidify, crystallize or
polymerize should not be allowed to stand in ball
valve cavities.
6. Torque Requirements – Operating torque
requirements will vary depending on the length of
time between cycles, line pressure, type of valve
seats, and the media in the system. For a detailed
analysis of valve torque requirements, see
Worcester’s Actuator Sizing Manual.
3.0 OPERATION AND
MAINTENANCE SECTION
1
.0
1. Valves should be opened and closed slowly to
avoid hammering effect on the valve and pipeline.
2. Valve should be “fully open” or “fully closed” to
prevent damage to the seat and ball caused by
wire drawing.
3. This valve is intended for on-off service and
should not be used in throttling applications.
4. If a stem leak develops, tighten the gland nut
until the leakage has been stopped. If the stem
leak cannot be stopped, replacement stem
packing is available.
CAUTION: For maximum stem seal life, proper stem
adjustment procedure must be followed. Excessive
tightening causes higher torque and shorter stem
seal life.
When replacing the packing, be sure that the
valve is not under pressure. Remove all actuation
to give access to the packing. After loosening and
removing the gland nut, the packing can be
removed by means of a hooked wire or a special
purpose tool.
5. If a through leak occurs, ensure that the valve
is fully closed. If leakage persists, replacement
seats are available.
6. If a body seal leak develops, do not over tighten
the body end cover bolting. This may damage the
valve. Instead a replacement
seal should be installed.