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Pneumatic actuator AT 3841 with limit switch box

Pneumatic single acting actuator including limit switch box for signal open/closed valve. for on-off and control of ball valves and butterfly valve or where 90° rotation is required.

Torque1 - 6600 Nm
Suitable for articlesAT3502, AT3507, AT3533S, AT3534S, AT3582, AT3585, AT3590, AT2282, AT 2310-2319


Article number Performance Torque (Nm) start Torque (Nm) stop Connection to valve ISO 5211 Amount
AT 3841-5-LSB Pneumatic single acting with limit switch box 20,9 17,5 F03/05/07, 14 mm
AT 3841-7-LSB Pneumatic single acting with limit switch box 50,8 42,4 F05/07, 17 mm
AT 3841-8-LSB Pneumatic single acting with limit switch box 81,3 65,5 F07, 17 mm
AT 3841-9-LSB Pneumatic single acting with limit switch box 104 93,8 F07/10, 22 mm
AT 3841-10-LSB Pneumatic single acting with limit switch box 164 143 F10, 22 mm
AT 3841-12-LSB Pneumatic single acting with limit switch box 238 204 F10, 27 mm
AT 3841-14-LSB Pneumatic single acting with limit switch box 588 478 F12, 27 mm
AT 3841-15-LSB Pneumatic single acting with limit switch box 1002 787 F14, 36 mm
AT 3841-16-LSB Pneumatic single acting with limit switch box 1321 1081 F14, 36 mm

Product information

Range of Application

Actuator for on-off and control of ball, butterfly and plug valves or where 90° rotation is demanded.

Program text

UEC.22 Actuator for valves pneumatic two position with spring return

Actuator AT3841 pneumatic, single acting for on-off and control of ball valves and butterfly valves or where 90° rotation is required.

Quality Assurance

Solenoid valve connection and actuator top acc. to VDE/VDI 3845 (NAMUR), adapter is required.
Mounting flange and stem square drilled acc. to ISO 5211 and DIN 3337, adapter is required.

The actuators meet the demands from the machine directive, MD 2006/42/EC and ATEX 94/9/EC.

All Kinetrol pneumatic actuators are classified for use in potentially explosive atmospheres as Group II Category 2, suitable for zones 1, 2, 21 and 22 in accordance with Annex VIII of Directive 94/9/CE (ATEX).

Material Specifiation

DetailQualityMaterialSurface treatment
1Body1Actuator 0-7 ZL16-BSEN1774:1998, larger actuators aluminum LM24Epoxy anodized C4 according to EN-ISO 12944-2
2Wing1Stainless steel
3Springs1Spring, Ur typePre-stressed

Dimension and weight

Actuator 3841-

Measurements in mm, weight in kg

Function and Design

The actuator only has one movable part which entails an outstanding operational dependability. The stroke length is adjusted simply with the help of stop screws on the side of the actuator. All actuators are function and tightness tested from a factory which guarantess 4 million operations. The actuators are modular and can be provided with limit switch box, positions, valve positioners and solenoid valve.

Mounting holes according to ISO 5211 and DIN 3337, for standardized mounting against the valve.

Headboards with adjustable screws for stroke length (5-10°).

Actuators AT 3841 single acting:
The actuator is delivered as a standard with a spring closing function. If a spring opening function is requested instead, it has to be specified while ordering.

Technical Information

Pressure:Supply pressure max 8 bar (e). Higher pressures on demand.
Temperature:-20°C to +80°C. Other ranges on request.
Manoeuvre medium:Air or inert gases, purity at least 40 micron.
(No requirements of mist lubrication). Oil or water.

Torque (Nm) AT 3841 singel acting

ActuatorAir Pressure (bar)
Standard spring set3,54,55,5Spring return
StartStopStartStopStartStopSame as for airStop
AT 3841-11,50,91,91,52,31,8

AT 3841-2

AT 3841-36,34,18,16,410,38,7
AT 3841-513,08,516,413,020,917,5
AT 3841-730,519,840,730,550,842,4
AT 3841-852,736,867,251,481,365,5
AT 3841-961,050,381,971,2104,093,8
AT 3841-1010778136114164143
AT 3841-12145111191158238204
AT 3841-14374249479367588478
AT 3841-15--8355951002787
AT 3841-16864576109783213211081
AT 3841-18187512502426184029542417
AT 3841-20--4514342354564464
AT 3841-30--6771513481846669

Air consumption

ActuatorOperating time/Consumption by 5,5 bar
Time in secondsAir consumption in liter

To calculate the exact time the valve's torque is required, contact Armatec.

Dimensioning AT 3840 double acting

Actuator size578910121415161820
Ball valve
AT 3502DN10-2532-506580100125-150200
AT 3507DN8-2032-40506580-100200
AT 3582, 3585DN15-2025-4050-6580100125-150
AT 3582HT, 3585HTDN1520-40506580100-125150
AT 2282DN80-100125150-250300350400500
AT 2310-2344DN50-6580-100125150200250-300350-400450-500600-700

Accessories and Options


  • Visual position indicator.
  • Emergency gear shift between actuator and valve.
  • Internally connected pressurized air tank for emergency operation.
  • Block for control timing
  • Valve block for air evacuation from the acuator without dissassembly of the control air lines.
  • Inductive or mechanical limit switch.
  • Valve positioner, 4-20mA or 3-15 psi.
  • Limit switch box.
  • 180° rotation
  • "Spring to center"


The actuator can be installed indoors or outdoors in any position. All though mounting the valve with the air connections upwards should be avoided to minimze the risk of water and dirt to get inside of the valve.

Maintenance and spare parts

The actuator should be disconnected electrically and pneumatically before assembly or dissassembly is started. The actuator should be mounted with even spaced distances.

Spare parts
The repair kit includes the neccessary soft parts.


Article number, series number, max allowed operation pressure.
Manufacturer, year of production.
CE-marking, Ex marking including class.

How to order

Example: AT 3841-5-LSB
AT 38415LSB
Article numberSizeLimit switch box