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PNEUMATIC · HYDRAULIC · QUARTER-TURN

A quarter turn, from 5 to 250,000 newton metres.

ACTREG builds the pneumatic and hydraulic actuators that drive ball, butterfly and plug valves. Two opposed pistons, one pinion, ninety degrees — and the torque has to be there at the seat, where the valve demands most of it.

Request a quoteSee the range
ASR/ADA — Rack & Pinion

Rack and pinion

SY01 scotch yoke pneumatic 1st generation — Scotch Yoke

Scotch yoke

SY02 scotch yoke hydraulic 1st generation — Scotch Yoke

Hydraulic

DG declutchable gear operator — Accessories

Accessories

Output torque
5 – 0Nm
Rotation
0°
± 5° both ways
Working pressure
0 bar
116 psig
Built since
0
Gavá, Barcelona

Two pistons. One pinion. Ninety degrees.

Drag the body, or the scale, and watch the opposed racks turn the pinion. Double-acting torque is constant because the lever arm never changes.

Plan view of an ACT-4000 body. Air into the end chambers drives both pistons inward; the opposed racks turn the pinion through 90° ± 5°, adjustable in both directions from outside the body.

Output torque

3 956Nm

2 918 lbf·ft at 6 bar

Across the quarter turn

Air stroke at 0°
3 956 Nm
Air stroke at 90°
3 288 Nm
Spring end torque
1 011 Nm

Thrust spent compressing the springs is thrust the valve never sees, so air-stroke torque falls as travel grows.

Butterfly disc

Closed0° of 90°

Actuator configuration
Configuration

Size 4000, spring set S08, figures from data sheet PDS-AC-4000.

From a 5 Nm damper to a 250,000 Nm pipeline ball valve.

Four mechanisms cover the whole span, and they overlap on purpose. Where two ranges meet, the choice is made on torque curve, weight and failure mode rather than on capacity alone.

Rack and pinion

ADA / ASR — 5 to 6 500 Nm

Scotch yoke, pneumatic double acting

SY01 — 293 to 258 616 Nm

Scotch yoke, pneumatic spring return

SY01 — 172 to 71 046 Nm

Scotch yoke, hydraulic double acting

SY02 — 315 to 250 000 Nm

Output torque in Nm, logarithmic

10
100
1 000
10 000
100 000

Two mechanisms do most of the work.

Rack and pinion for compact, constant-torque duty; scotch yoke when the valve needs its torque at the seat and the figures run into six digits. Hydraulic and electric drives sit on the same valve interface.

The seal compound sets the temperature window.

Everything else about a rack and pinion body stays the same across the four constructions below. Choosing one is a question of how cold the site gets in winter and how hot the line runs in service.

NBR O-ring

Standard construction

-30 °C100 °C

FKM O-ring

High temperature

-15 °C150 °C

Silicone O-ring

Low temperature

-40 °C80 °C

Silicone O-ring, 316 pinion

Very low temperature

-55 °C80 °C

Ambient and process temperature in °C

-40
0
40
80
120

Built to the interfaces your valve and skid already use

ISO 5211
Valve mounting flange and drive dimensions
DIN 3337
Octagonal drive on the actuator output
NAMUR
Direct solenoid valve mounting, no external tubing
VDI/VDE 3845
Accessory bracket for switchboxes and positioners

Where ACTREG actuators are working.

Anything that turns through a quarter of a circle is in scope.

  • Ball valves
  • Butterfly valves
  • Plug valves
  • Damper and air valves
Oil and gas
Wellhead, separation and export duty, including offshore platforms where spring-return actuators carry the emergency shutdown function.
Chemical and petrochemical
Reactor and transfer lines where seal compound and epoxy grade are selected for the process medium and the surrounding atmosphere.
Power generation
Feedwater, cooling and fuel gas service, with high-temperature FKM construction for steam-adjacent duty up to 150 °C.
Water and wastewater
Butterfly valves on large-diameter mains, where a compact rack and pinion body keeps chamber and headworks space free.
Pharmaceutical
Clean utility and transfer skids needing documented, repeatable quarter-turn travel and nickel-plated external surfaces.
Food and beverage
Wash-down environments where the C5 epoxy coating and watertight covers resist frequent cleaning cycles.
Metallurgy
Furnace gas and cooling circuits at high ambient temperature, with opening limiters set to the valve's own travel.
Pulp and paper
Stock and chemical recovery lines running continuously, where maintenance-free travel stops matter more than peak torque.

Five sites, spread across 195 degrees of longitude.

Assembly and engineering sit in Gavá, outside Barcelona. Shanghai manufactures for Asia-Pacific, and stock in Kettering, Québec and Sorocaba keeps lead times short in each region.

Questions that come up before an enquiry.

If the answer you need is not here, the engineering team in Gavá will size an actuator against your valve torque figures.

What is the difference between a rack and pinion and a scotch yoke actuator?

A rack and pinion actuator produces constant torque across the full quarter turn, while a scotch yoke produces its highest torque at the ends of travel. Rack and pinion suits valves with an even torque demand up to about 6,500 Nm; scotch yoke suits large ball and butterfly valves whose demand peaks at the seat, and reaches 250,000 Nm.

How much torque does an ACTREG actuator produce?

The range covers 5 Nm to 250,000 Nm. Rack and pinion units span 5 to 6,500 Nm across sizes 10 to 4000, with the largest producing 6,421 Nm at 8 bar. Scotch yoke units run from 293 Nm to 258,616 Nm pneumatically and from 315 Nm to 250,000 Nm hydraulically.

Why does spring-return torque fall as the actuator strokes?

On the air stroke a spring-return actuator spends part of its piston thrust compressing the springs, so the torque reaching the valve falls as travel increases. A size 4000 with the S08 spring set delivers 3,956 Nm at 0° and 3,288 Nm at 90° on a 6 bar supply. On the spring stroke the opposite happens: torque is highest the moment air is lost and lowest at the seat, which is why the spring end torque is the figure that must cover valve demand.

What valve standards do ACTREG actuators mount to?

Valve connections follow ISO 5211 with a DIN 3337 octagonal drive. Solenoid valves mount directly to the NAMUR interface with no external tubing, and switchboxes or positioners mount on the VDI/VDE 3845 accessory bracket.

What is the maximum operating temperature?

Standard NBR construction on the rack and pinion range covers −30 °C to +100 °C. FKM O-rings extend the upper limit to +150 °C, silicone O-rings take the lower limit to −40 °C, and silicone O-rings with a 316 stainless pinion reach −55 °C. Scotch yoke constructions are published separately: standard −20 °C to +80 °C, low temperature −40 °C to +80 °C, high temperature −20 °C to +120 °C, and extreme low temperature down to −60 °C.

Can the 90° travel be adjusted after installation?

Yes. Rack and pinion units adjust ±5° between 85° and 95° using screws in the body, in both directions of travel, and the screws are sized to absorb full rated torque plus the shock load of the stop. Scotch yoke units adjust between 80° and 100° on external travel stops.

Is a spring-return actuator safe to work on?

Yes. The rack and pinion spring cartridges are designed so springs can be replaced without releasing stored energy into the assembly, which removes the main hazard in spring-return maintenance.

Can an ACTREG actuator carry an emergency shutdown function?

Yes. A spring-return unit fails to its safe position when supply pressure is lost. On the scotch yoke range a single-acting spring cylinder mounts to either side of the modular centre body, so a double-acting actuator can be converted to emergency shutdown duty without changing the valve interface.

Send us the valve, we will size the actuator.

Quotations come back with the torque calculation, the spring set and the construction we would specify, so the figures can be checked against your own.

Request a quoteEmail engineering
What to send
Valve type and size, required torque including safety factor, available supply pressure, failure mode, and the ambient and process temperatures.