Frenstar Valves

Valve Manufacturer, Stockist & Project Solution Specialist

Valve Actuation

Frenstar offer an extensive valve actuation range of pneumatic, electric and hydraulic actuators with accessories:

  • Single Acting Spring Return
  • Double Acting
  • Pneumatic Type
  • Hydraulic Type
  • Electric Type

Frenstar can supply Butterfly valves complete with factory fitted pneumatic El-O-Matic/Intervalve actuators. EL-O-Matic Pneumatic actuators are powerful and compact double rack and pinion units for use with ball, butterfly and plug valves and any device requiring accurate and dependable quarter turn rotary motion. 

EL-O-Matic’s patented 3 point piston support provides a tough reliable unit for the automation of today’s high performance industrial valves. Safety features include an anti-blow out spindle and a spring retaining system which ensures no spring tension on disassembly.

‘E’ Series actuators incorporate a body of cast aluminium and have pistons where the rack teeth are precision machined onto the aluminium casting. Spring return versions have a maximum of 6 springs, 3 in each end cap assembled as a concentric stack.

‘P’ Series actuators cover the large end of the torque range. These all incorporate a body of cast aluminium and have steel for the rack on pinion drive. Spring return versions have a maximum of 14 springs 7 in each end cap assembled within a hexagon pattern.


  • Double Acting Actuator
  • Single Acting Actuator
  • Actuator with  carbon steel housing  for offshore/arduous duties 
  • Actuator with 180° rotation  
  • Three position Actuator
  • Limit stops in the end caps
  • Limit stop with Limit stop plate
  • Actuator with ±3° extra travel 
  • Full system supply including switchboxes, solenoid valves, positioners etc.
valve actuation
E Series Pneumatic Rack and Pinion Actuators


  • ‘E’ Series
  • ‘P’ Series


Pressure Up to 8 bar
Temperature -20°C to 80°C
Media Air (dry or lubricated)
Non-corrosive gas or light hydraulic oil
Construction Suitable for indoor or outdoor installation
Material Housing – Aluminium alloy
Drive Shaft Carbon Steel
Finish Two coat polyurethane
Rotation (Standard) Counter-clockwise to open with port “A” pressurised
Spring return Actuators air fail to close clockwise
Movement (Standard) 91.5°C from -0.5°C to 91° counter-clockwise
Lubrication Factory lubricated for the normal life of Actuators
Life 500,000 operations minimum

The benefits of supplying with factory fitted actuators are:

  • Significantly reduces cost
  • Saves time 
  • Excellent lead times  
  • Factory tested, ready for immediate installation 
  • Full manufacturers warranty for valve and actuator system

Frequently Asked Questions

How does a valve actuator work?

A valve actuator operates the opening and closing of a valve utilising pneumatic or hydraulic pressure or electricity. This is an alternative to manually operated by a plant worker, allowing remote adjustment or rapid operation of larger valves.

How does a pneumatic actuator work?

Pneumatic actuators rely on a form of pressurised gas, often compressed air entering a chamber, where the air/gas builds up pressure. When the pressure reaches a certain level there is a controlled movement of a piston or gear either in a straight line or in a circular motion.

What is the difference between spring return and double acting actuators?

Spring-return (single) actuators supply power/pressure to only one side of a piston, the spring powers the alternate side moving the valve to open or close position. In contrast, the double-acting actuator uses piston element to operate the valve therefore both chambers require pressurisation.