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Valtek Spring Cylinder Rotary Actuator Technical Brochure

Valtek Spring Cylinder Rotary Actuator Technical Brochure
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Valtek Spring Cylinder Rotary Actuator Technical Brochure - 1

Spring Cylinder Rotary Actuators TB031 RotaryAct 07(9-01).p65

Valtek Spring Cylinder Rotary Actuator Technical Brochure - 2

_____ Flow Control Division ^ Valtek Control Products Valtek Spring Cylinder Rotary Actuators High interchangeability reduces spare part Rocking piston provides direct Compact, lightweight design for easy handling, limited space Sliding seal reliable, long-life Adjustable stroke stops prevent excessive rotation fail-safe operation zero lost motion Figure 1: Spring Cylinder Rotary Actuator Features The Valtek® spring cylinder rotary actuator combines high torque and pneumatic stiffness with excellent throt- tling capabilities. These characteristics are designed into a lightweight, rugged and...

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Valtek Spring Cylinder Rotary Actuator Technical Brochure - 3

Valtek Spring Cylinder Rotary Actuators Features and Advantages The Valtek spring cylinder rotary actuator features high torques, positioning stiffness and easy maintenance to produce a high-performance rotary actuator that excels in maintenance-free throttling and on/off control applications. Features Achieves higher torques Obtains stiff piston positioning Permits higher ∆P limits on valve Rocking piston Provides direct connection to shaft Assures zero lost motion between actuator and valve Utilizes fewer parts Splined shaft and lever Allows zero lost motion Compact, lightweight, rugged...

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Valtek Spring Cylinder Rotary Actuator Technical Brochure - 4

Valtek Spring Cylinder Rotary Actuators Stiffness and Performance For a size 25 cylinder actuator (typical for a 2-inch DN25 valve) with a supply air pressure of 100 psi (6.9 bar), the spring rate would be nearly 10,000 pounds per inch (11,500 kg/cm) near the seat. As the volume under the piston becomes smaller, the stiffness factor becomes larger in the Valtek spring cylinder rotary actuator. The result of the higher actuator stiffness in cylinder actuators is that rotary valves can be operated in the flow-toclose orientation without position fluctuations caused by dynamic forces (flow...

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Valtek Spring Cylinder Rotary Actuator Technical Brochure - 5

Valtek Spring Cylinder Rotary Actuators Performance and Options The high air-handling capacity of the positioner, combined with relatively low cylinder volumes, produces fast stroking speeds. High operating speed is achieved with virtually no overshoot when approaching the final disc or ball position. At the same time, static sensitivity of the unit is excellent. For example, as little as 0.017 psi (0.0017 bar) is required to rotate the shaft 0.01 degrees (the minimum detectable movement in the tests conducted) on a size 25 actuator. A signal change of only 0.02 psi (0.0014 bar) is required...

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Valtek Spring Cylinder Rotary Actuator Technical Brochure - 6

Valtek Spring Cylinder Rotary Actuators Torque Output Table I: Net Torque Output of Actuators at Various Supply Pressures, lbs/in (kg/cm) Actuator Supply Size Pressure psi bar 150 10.3 140 9.7 120 8.3 100 6.9 80 5.5 60 4.1 Spring Torque Degrees from Fall Position on Air Supply Loss 0 STD 100 with Dual Springs STD 200 with Dual Springs NOTE: For air-to-open/fail-closed actuators the 0° position shown above corresponds to the disc or ball being seated. For air-to-close/fail-open actuators the 90° position shown above corresponds to the disc or ball being seated. *Size 200 actuator limited to...

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Valtek Spring Cylinder Rotary Actuator Technical Brochure - 7

Valtek Spring Cylinder Rotary Actuators Specifications Table II: Rotary Actuator Data Actuator Size Spring Design Upper Cylinder Area Spring Rate Lower Cylinder Area in2 * Valve in closed position ** Estimated, including Beta positioner Table III: Actuator Specifications Table V: Materials of Construction Cylinder with positive spring action Sizes 25, 50, 100 and 200 Spring Single (std.), heavy-duty, Designs dual Action Field-reversible: air-to-open, air-to-close Operating Pressure Up to 150 psi** (10.3 bar) Temperature Range -40° - 350°F* (-40° - 177°C) Ductile iron Transfer Case Anodized...

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Valtek Spring Cylinder Rotary Actuator Technical Brochure - 8

Valtek Spring Cylinder Rotary Actuators Dimensions Table VIII: Rotary Actuator Dimensions (inches/mm) Size (extended spring) Press. Conn. *7.8/198 on size 100 and 200 actuators, 16-inch (DN 400) and larger valves. **7.9/202 on size 50 actuators and 8, 10-inch (DN 200, 250) valves; 9.4/238 on size 100, 200 actuators and 8,10,12-inch (DN 200, 250, 300) valves; 11.3/286 on size 100, 200 actuators and 16-inch (DN 400) and larger valves. NOTE: Disassembly clearance (E) includes lifting ring on sizes 25 and 50 Flowserve Corporation has established industry leadership in the design and manufacture...

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