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Neles™ Cylinder Actuator, B1 Series

About Neles™ Cylinder Actuator, B1 Series

Neles double acting and spring return B1-series piston type quarter turn actuators are designed for use in both modulating control and on-off service.

Technical Specifications
Technical specifications
Manufacturer Downloads
Technical specifications


B1 Series pneumatic cylinder actuators are designed for remote on/off control service. Double-acting (B1C) or spring return open/closed in case of air failure (B1J) are available. The actuators’ unique articulated lever crank design provides a torque output signature, which is particularly suited to automating ball and butterfly valves.

Designed to perform in harsh environment

Built to perform in Artic and high-temperature conditions, the B1 series can perform in an environment where the temperature goes down to – 55°C (with Artic option) and up to 120°C (with High temp. option). Standardly designed to fit IP66 standards in order to efficiently protect the mechanism from ambient dust and moisture. It is SEL 3 capable.

Benchmark for robustness and reliability

The B1 Series is guaranteed to perform optimally for 1 million cycles before you will ever have to conduct maintenance. This high reliability comes from 2 factors;

  1. The double pivots principle allows the actuator to push straight on the piston’s shaft which minimizes lateral displacement of the piston to lower the friction at the piston rod seal.
  2. The piston rod seal comes standard with the long-run Double-Delta seal which allows minimum friction from the piston’s shaft.

Even more, with the S (super long run) option, the piston rod seal now has a lip seal design which minimizes the friction at the piston shaft even more. The S option also comes with optimized and more durable material for the bearing’s connection arm. With this option, Valmet added a Darmex precision lubricant to the cylinder pipe, piston rod, and lip seal to ensure the actuator will perform even more cycles than the standard version.

Engineered to perform

The actuator generates maximum torque at 0° when, for example, a ball or butterfly valve is closed, and the need for torque is at its peak. The second increase in torque is achieved at 60-80°. This is the position where the need for torque on a valve is high, caused by the dynamic forces of the media flowing through the pipes. This actuator torque slope is unique due to the double pivots design. The B1 series design gives the actuator the torque it needs when it needs it.


Pneumatic cylinder actuator
B1C – double action
B1J – spring return
Supply pressure:
2.8 – 10 bar
Torque range:
28 – 100000 Nm
Temperature ranges:
-55 to +120 °C
Protection class:
IP66, IP67 (IEC 60529)
ATEX class:
Mounting face:
ISO 5211, VDI/VDE 3845

Functioning Principle

Fail closed


Fail open

  • Wear and corrosion resistant design
  • Safe and easy maintenance
  • Suitable for various services, from control to demanding ESD and arctic conditions
  • Vast number of optional features
  • Rugged design
  • Wide torque range
  • Type approval according to EN 15714-3
  • Applications:
    • Emergency shutdown
    • Compressor anti-surge
    • High cycle control and on-off applications
    • High precision control
    • Arctic service