Valtek Spring Cylinder Rotary Actuator Technical Brochure

Product catalog summary

Introduction
The Valtek Spring Cylinder Rotary Actuator by Flowserve Corporation is engineered for high torque and pneumatic stiffness, suitable for quarter-turn applications. It is compatible with the Valdisk high-performance butterfly valve and the ShearStream V-notch ball valve. The actuator is compact and lightweight, featuring adjustable stroke stops, a rocking piston for direct shaft connection, and a durable sliding seal assembly.

Features and Advantages
The actuator supports supply pressures up to 150 psi (10.3 bar), offering high torque and stiffness. It includes a splined shaft and lever for zero lost motion, low-friction bearings for minimal wear, and a fail-safe spring for safety. The design facilitates easy maintenance and installation in confined spaces. It is field-reversible with interchangeable parts to minimize inventory costs.

Stiffness and Performance
The actuator delivers higher torque than diaphragm actuators by operating at higher pressures. It provides exceptional stiffness for precise throttling control, particularly near the valve seat, ensuring stable operation even with dynamic forces.

Performance and Options
The actuator offers fast stroking speeds with high sensitivity and minimal overshoot. It boasts excellent frequency response, low hysteresis, and repeatability, ensuring consistent response to controller signals. Options include a declutchable handwheel for manual operation and heavy-duty springs for high shutoff pressure applications.

Torque Output
Detailed tables in the document show the net torque output of actuators at various supply pressures and positions, varying with actuator size and supply pressure, with configurations for air-to-open/fail-closed and air-to-close/fail-open actuators.

Specifications
The actuators are available in sizes 25, 50, 100, and 200, with single or dual spring designs. They are field-reversible with air-to-open and air-to-close actions. Operating pressure is up to 150 psi (10.3 bar), and the temperature range is -40° to 350°F (-40° to 177°C). Special O-rings are needed for temperatures outside the standard range.

Actuator Data
The document includes tables with actuator stroke, moment arm, air supply, spring design, and cylinder area specifications. For example, size 25 actuators have a stroke of 1.88 inches and a maximum air supply of 150 psi.

Stroking Speeds
Stroking speeds for 90° rotation are provided, with standard and optional tubing sizes affecting the speed. Size 25 actuators have a stroking time of 1.0 seconds with 1/4-inch tubing.

Materials of Construction
Key components include ductile iron yokes, anodized aluminum transfer cases, and 416 stainless steel stems. Bearings are made of filament-wound fiberglass with PTFE liners.

Ordering Information
Customers must provide details such as operating conditions, maximum air supply pressure, valve rotation, actuator torque, and stroking time requirements when ordering.

Dimensions
The document lists dimensions for each actuator size, including disassembly clearance and connection specifications.

Additional Information
Flowserve emphasizes the importance of proper selection, installation, and maintenance of their products, providing general guidelines but stressing user responsibility for correct application.

Contact Information
Flowserve Corporation provides contact details for their regional headquarters and quick response centers for further inquiries.

Catalog excerpts

Valtek Spring Cylinder Rotary Actuator Technical Brochure-1

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

Open the catalog to page 1

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 compact...

Open the catalog to page 2

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 Permits...

Open the catalog to page 3

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 fluctuations)....

Open the catalog to page 4

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 to...

Open the catalog to page 5

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 80...

Open the catalog to page 6

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 aluminum...

Open the catalog to page 7

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 of...

Open the catalog to page 8