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I ntroduced
and patented by Red Valve, the air -actuated Type
A Pinch Valve offers a unique, cost-effective
solution to flow control problems. More Red Valve
Type A Valves are in use than any other Pinch
Valve throughout the world. The secret is
in the rubber sleeve - the valve’s only wetted
part.
Actuation of the valve, the pinching action is
accomplished by air or hydraulic pressure placed
on the sleeve. The valve body acts as a
built-in actuator, eliminating costly pneumatic,
hydraulic, or electric actuators. Adding
air pressure within the annular space between
the body and the sleeve can open, throttle, or
close the valve.
The sleeve’s flexibility allows the valve to close
“drop tight” around entrapped solids, eliminating
hang ups damaging the valve itself.
Sealing area is equal to 95% of the valve’s length.
With Red Valve Type A Pinch Valves, there are
no seats or packing to replace, or cavities or
dead spots to collect debris and bind valve operation.
Their abrasion resistance is unmatched.
When the valve is open, it is like a straight
piece of pipe in the line. Type A Valves
are used on remote locations or harsh environments
since there are no external links, levers, pistons,
or rotating parts to cause downtime. In general,
25-35 psi over line pressure is required for full
closure of Red Valve Type A Pinch Valves.
Control
Throttling control is accomplished by using a
booster or proportional relay to modulate air
pressure to the Type A Valve. A changing
air signal through the proportional relay will
modulate the Type A Valve.
Type A Double Wall
Designed for highly abrasive applications, the
Type A Double Wall
Sleeve Valve outlasts even stellited V-Ball
valves and metal seated valves on abrasive slurries.
To compensate for the extra sleeve thickness,
the valve body is increased to the next size.
Type A Cone
Type A valves equipped with a cone
sleeve are designed specifically for throttling
control applications. By reducing the effective
port size, the Cv of the valve can match the Cv
required.
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