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API Specification 6D Twenty-second Edition - Introduction |
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6.10 Handwheels and wrenches
(levers)
Wrenches for valves shall either be of an
integral design or consist of a head which fits
on the stem and is designed to take an extended
handle. The head design shall allow permanent
attachment of the extended section if specified
by the purchaser.
The maximum force required at the handwheel or
wrench to apply the breakaway torque or thrust
shall not exceed 360 N.
Wrenches shall not be longer than twice the
face-to-face or end-to-end dimension of the
valve.
Handwheel diameter(s) shall not exceed the
face-to-face or end-to-end length of the valve
or 1 000 mm, whichever is the smaller, unless
otherwise agreed. Except for valve sizes DN 40
(NPS 11/2) and smaller, spokes shall not extend
beyond the perimeter of the handwheel unless
otherwise agreed.
When specified by the purchaser, the handwheel
of the gearbox input shaft shall be provided
with a torque-limiting device, such as a shear
pin, to prevent damage to the drive train.
6.11 Locking devices
Valves shall be supplied with locking devices if
specified by the purchaser. Locking devices for
check valves shall be designed to lock the valve
in the open position only.
Locking devices for other types of valve shall
be designed to lock the valve in the open and/or
closed position.
6.12 Position indicators
Valves fitted with manual or powered actuators
shall be furnished with a visible indicator to
show the open and the closed position of the
obturator.
For plug and ball valves, the wrench and/or the
position indicator shall be in line with the
pipeline when the valve is open and transverse
when the valve is closed. The design shall be
such that the component(s) of the indicator
and/or wrench cannot be assembled to falsely
indicate the valve position.
Valves without position stops shall have
provision for the verification of open and close
alignment with the operator/actuator removed.
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