The Neles VD Series pneumatic linear diaphragm actuator is a linear, single-acting actuator with spring return. It delivers thrust from 1890 to 22800 N, provides a long cycle life and a field-adjustable fail-action direction, and is certified to IEC 61508 SIL 3 with an anti-corrosion coating. It is suitable for continuous process control, on-off control, and safety instrumented systems, and can withstand harsh weather, chemicals, and petroleum environments.
Neles pneumatic linear diaphragm actuator, VD Series
Neles
Neles VD Series Pneumatic Linear Diaphragm Actuator
Pneumatic linear diaphragm actuator with spring-to-open or spring-to-close configuration.
- Category
- Actuators
- Operating pressure range
- 3.2 - 4.2 bar / 46 - 60 psi
- Operating temperature range
- -55 to +85 °C / -67 to +185 °F
Specifications
- Actuator type
- Pneumatic diaphragm actuator
- Operating action
- Linear single-acting, spring return
- Operating pressure range
- 3.2 - 4.2 bar / 46 - 60 psi
- Operating temperature range
- -55 to +85 °C / -67 to +185 °F
- Output thrust range
- 1890 - 22800 N / 424 - 5125 lb.f
- Spring range
- Universal spring 0.8 bar - 2.6 bar / 11 psi - 37 psi
- Spring action setting
- Field-reversible configuration for spring-to-open or spring-to-close operation
- Safety integrity level
- Compliant with IEC 61508 and suitable for safety integrated systems up to and including SIL 3
- Environmental resistance
- Anti-corrosion coating for resistance to harsh weather, chemicals, and petroleum environments
Application scenarios
Process control with linear control valves
Drives linear control valves with low to medium thrust requirements and is suitable for valve position control in continuous processes. Low friction and high control performance support reliable regulating control.
Automatic control of linear on-off valves
Drives linear on-off valves for open-close control. The single-acting spring-return design can be configured on site for spring-to-open or spring-to-close operation to meet the specified fail-action direction upon loss of air supply.
Linear valve actuation in safety instrumented systems
Acts as the linear valve actuator in safety instrumented systems, using spring return to move the valve to the predetermined position when a safety action is triggered. The product complies with IEC 61508 and is suitable for safety-integrated systems up to and including SIL 3.
Linear valve automation in harsh environments
Controls or operates linear valves in harsh weather, chemical, or petroleum environments. The anti-corrosion coating improves the actuator's resistance to relevant environmental conditions.
High-cycle operation of linear valves
Operates linear valve assemblies that require long-term repeated modulation or frequent on-off cycling. The product provides extremely long cycle life and is suitable for continuously operating automated process sections.
Selection points
On-site reversal of spring action
The spring action can be configured on site for spring-to-open or spring-to-close operation, supporting linear valve actuator selection where different fail-safe directions are required.
Suitable for linear valves with low to medium thrust requirements
The actuator provides an output thrust range of 1890 to 22800 N and is suitable for linear valves with low to medium thrust requirements in both regulating and on-off applications.
Meets SIL 3 safety-integrated system requirements
The product complies with IEC 61508 and is suitable for safety-integrated systems up to and including SIL 3.
Harsh-environment compatibility and corrosion resistance
The product features an anti-corrosion coating that protects against harsh weather, chemicals, and petroleum environments, making it suitable for actuator selection under corresponding environmental conditions.
Installation notes
Operating air supply pressure limits
The on-site air supply pressure should be maintained within the specified operating pressure range of 3.2 to 4.2 bar (46 to 60 psi) for the VD Series actuator.
Confirm and set the spring-return action direction
Before installation, confirm the required spring-to-open or spring-to-close action direction and configure the actuator accordingly for site requirements. The actuator supports on-site reversal of the spring action.
FAQ
What valve control applications are suitable for the Neles VD Series pneumatic linear diaphragm actuator?
The VD Series is suitable for modulating and on-off control of linear valves, particularly linear valves requiring low to medium thrust. Its spring-return design can be used in applications requiring a fail-safe action on loss of air supply. The specific configuration must be confirmed based on the actual model and application conditions.
How should the VD Series actuator thrust and supply pressure be selected for process conditions?
Selection should consider the required valve thrust, travel, control or on-off requirements, fail-action direction, and site environmental conditions. The VD Series provides an output thrust range of 1890 to 22800 N, an operating pressure range of 3.2 to 4.2 bar, and universal spring range options from 0.8 to 2.6 bar.
Can the spring-to-open and spring-to-close direction of the VD Series be adjusted?
Yes. The VD Series can be field-reconfigured for spring-to-open or spring-to-close operation, helping match the valve's required safe position when the air supply fails. Before making adjustments, confirm the actuator model, valve action direction, and system safety requirements.
Is the VD Series suitable for low-temperature, outdoor, or chemical-service environments?
The series has an operating temperature range of -55 to +85 °C and features an anti-corrosion coating that provides resistance to harsh weather, chemicals, and petroleum environments. Specific media exposure conditions, installation locations, and long-term protection requirements must still be evaluated for the actual application.
What VD Series configurations support installation, operation, and maintenance?
The VD Series can be equipped with optional mechanical travel stops and a side-mounted handwheel for convenient operation, facilitating travel limitation and manual field operation. Its low-friction diaphragm design supports precise control and reliable operation, while the simple construction helps reduce maintenance complexity.