Flowserve Double-Disc Gate Valve Sizes 2.5 - Manual (Page 8)

Anchor/Darling Double Disc Type Gate Valves FCD ADENIM0003-01 - 07/14
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3.3.4 It is recommended that the valve be installed with the stem
vertical, when possible. This orientation provides enhanced
packing life and simplifies disassembly/reassembly.
3.3.5 Following installation of the valve in the line, install the packing
supplied with the valve. (See maintenance Section 5.4 for
specific instructions). This operation may be performed
following valve cleaning if more convenient.
3.3.6 Before the valve is placed in operation, check all bolting for
tightness and lubrication per section 5.5.
4.0 Operating The Valve
Prior to operating the valve for the first time, verify that the valve
has been prepared in accordance with the preceding sections of this
manual.
4.1 Hand actuated
Handwheel actuated valves close on clockwise rotation of the wheel and
open counter-clockwise. This is true also for the handwheel on gear
and motor actuators.
4.1.1 Flowserve valves, if properly set up and maintained, will close
with ordinary effort on the handwheel. The required total force
at the rim of the handwheel should not exceed 100 lbs. and will
usually be much less. If tight shut-off is not achieved do not
use “cheaters” or other means of extra leverage. Instead, open
and close the valve once in an attempt to dislodge any foreign
matter on the sealing area that may be interfering with closure.
If this fails, disassemble the valve and inspect the internals for
galling or other damage.
4.1.2 The impactor feature on valves supplied with impactor
handwheels is intended to be used only in unseating the disc. If
the impactor is used to seat the disc it may be difficult to reopen
the valve.
4.2 Motor actuated
4.2.1 The motor actuators are adjusted for correct operation when
shipped from the plant. It should not be necessary to re-adjust
the torque and limit switches when the valve is placed in
operation unless the actuator has been removed from the valve
or the switch adjustments have been tampered with.
4.2.2 Adjustments of torque or limit switches should not be
attempted without first consulting Service Engineers. Failure
to obtain proper authorization when resetting torque or limit
switches may void the warranty.
Under no circumstances should the torque and/or limit switches
be completely bypassed.
They are included to provide protection of the valve internals.
Removal of their protection can cause extensive damage to the
equipment.
4.2.3 The valve is normally supplied with the torque switch wired
to stop the actuator in the closed position and the limit switch
wired to stop in the full open position. Using the torque switch
to control travel in the opening direction may damage the
backseat. The valve should be backseated only by using the
handwheel.
4.2.4 When powering the actuator for the first time, observe that the
direction of rotation is correct. If not, the power leads must be
reversed.
4.2.5 Manual operation may be performed at any time by pulling the
declutch lever downward.
The lever will stay in the manual mode until the electric motor is
actuated whereupon it will automatically disengage.
4.3 Operating tips
Do:
• Operate valves at least every 6 months.
• Keep stem clean and lubricated.
• Inspect valves regularly.
• Lap seats promptly if valve leaks.
• Use normal torque on handwheel.
• Check packing regularly.
Do Not:
• Over tighten packing.
• Torque-out motor operator against backseat.
• Keep valve backseated during normal operation.
• Keep gate valve in a partially open position for any
length of time or use for throttling.
• Bypass or reset torque or limit switches.