Rack and pinion actuators

A compact pneumatic actuator for quarter-turn valves up to 6,500 Nm, built on an anodised aluminium body with two opposed pistons driving a central pinion. Because the lever arm never changes, double-acting torque is constant across the full 90°.

Output torque: 5 – 6 500 Nm; sizes 10 to 4000, at 8 bar
Rotation: 90° ± 5°
Series: ADA / ASR
Sizes: 10 – 4000
Working pressure: 8 bar; 116 psig maximum

Series

ADA
Double acting
ASR
Single acting, spring return

General characteristics

ADA is double acting and ASR is single acting with spring return. The drive is a rack and pinion, so double-acting torque is linear — the same figure at every angle of the quarter turn. Travel is 90° ± 5°, set on external screws. The plungers carry an anti-friction element and the air passages run inside the body, so there is no external tubing to damage or freeze.

Springs are replaced without releasing stored energy into the assembly. A solenoid valve mounts to the NAMUR face; switchboxes and positioners mount to VDI/VDE 3845; the valve connection is ISO 5211 with a DIN 3337 octagonal drive. The position indicator is also the driver for limit or proximity switches.

5 to 6,500 Nm across sizes 10 to 4000
8 bar (116 psig) maximum working pressure
Constant torque through the whole quarter turn
Springs replaced without releasing stored energy

Optional constructions

Quick-release fasteners
Opening limiters
Epoxy-coated body, C3, C4 or C5
Electroless nickel on the body and covers
High-temperature construction

Operating temperature

The seal compound sets the window. Everything else about the body stays the same across the four constructions.

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

120

Coatings for corrosive atmospheres

An ACTREG pneumatic actuator has to be protected against external corrosion by the material of the body or by a surface treatment applied to it. The standard body is anodised aluminium. Where the atmosphere needs more, the published options are an epoxy coat to C3, C4 or C5, and electroless nickel on the body and covers.

Anodised
C3
C4
C5
Electroless nickel

Bi-directional travel adjustment

Each unit has a travel stop in both directions. The screws in the body set ±5° of stroke, so the assembled travel can be anywhere between 85° and 95°. The screws are sized to absorb the actuator's full rated torque and the shock load of the stop itself.

To change a limit, slacken the lock nut, turn the corresponding screw — left or right, to close the angle or open it — and tighten the nut again.

85°90°95°

Factory testing

Every actuator is tested individually on an electronic bench before it leaves Gavá. The bench checks pneumatic sealing between the chambers and confirms the rotation. Each body is marked with the year and month of production, the size and the casting number.

Data sheets

Current sheets for the rack and pinion actuators range. Every sheet carries its revision in the file name, so you can tell at a glance whether the copy in your project folder is the one in force.

Dimensional drawings, STEP models and the full catalogues are in the download library.

Published torque, size 4000

The largest size in the range, shown across the full supply pressure band. Smaller sizes scale down from the same geometry.

Output torque for the ACTREG size 4000 rack and pinion actuator by supply pressure, for double-acting and spring-return configurations.
Supply pressure	ADA, any angle	ASR at 0°	ASR at 90°
3 bar	2 408	1 549	880
3.5 bar	2 809	1 950	1 282
4 bar	3 210	2 351	1 683
4.5 bar	3 612	2 752	2 084
5 bar	4 013	3 154	2 485
5.5 bar	4 414	3 555	2 887
6 barstandard	4 816	3 956	3 288
6.5 bar	5 217	4 358	3 689
7 bar	5 618	4 759	4 091
8 bar	6 421	5 068	4 399

Spring stroke, 90° to 0°: 1 797 Nm falling to 1 011 Nm
Weight: 129.4 kg ADA, 164.7 kg ASR
Source: Data sheet PDS-AC-4000 Rev. 6, spring set S08

All figures in newton metres. Spring-return end torque is the figure that must cover valve demand at the seat, because the springs have the least left to give at the end of their stroke.

Interfaces

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