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Ball Valves
Accurate setting of ball valves to ensure:
- Complete shutoff.
- Full porting to reduce noise,
cavitation and pressure drop.
- Allow Pig clearing of the line.
Butterfly Valves
Accurate setting to ensure:-
- Tight shutoff without damaging the
seat.
- Tight shutoff without driving the disc
into the seat and requiring high breakout torques.
- Full flow when open reducing noise,
cavitation and pressure drop.
Stops can be used as a transiting feature
such that rubber lined valves aren't damaged when the valve is bolted
into the line and the seating getting damaged when the valve is first
opened.
Plug Valves
Accurate setting to ensure:-
- Tight shutoff to prevent 'wire
drawing'.
- Full flow when open to reduce noise,
cavitation and pressure drop.
Dampers
Accurate setting to ensure:-
- Damper blade closure without damaging
the mechanical linkage.
- Precise closure can be obtained easily
without clamping and unclamping the linkages.
- Intumescent strip damage is reduced.
- Full flow when fully open reducing
noise.
How is this achieved?
- By two stops striking the pinion
- This was chosen in preference to a piston
stopped solution as it acts on the primary motion in direct contact
with the valve. This reduces one element of backlash and potential
error/inaccuracy.
- Piston stopped solutions also introduce
complexity and potentially a more unreliable seal option as the piston
inward control may have to pass through the piston.
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