Stainless Steel DYNATORQUE 90 Worm-Gear Operators | SLB

Stainless Steel DYNATORQUE 90

Quarter-turn worm-gear operators

close up of multiple gears

Stainless steel DYNATORQUE 90 quarter-turn worm-gear operators are designed for use with valves and dampers, as well as most other quarter-turn applications requiring a self-locking mechanism.

For aggressive environmental conditions or corrosive applications, these operators have external components constructed of cast CF-8M stainless steel. They are completely sealed and are ideal for applications such as brewing, food processing, leaching operations, offshore platforms, and pulp and paper plants.

Gear operators with stainless steel internal parts also are available. DT21 is suitable for use with chainwheel operators, DT3 and DT7 are not suitable for chainwheel operation. These actuators are not recommended for use with handwheels over 18-in diameter and are not recommended for use with any of our chainwheel options.

Unit housings, covers, indicators, and bolting hardware are 300 series stainless steel. For gears suitable for even more harsh conditions, see DYNATORQUE DT quarter-turn severe-service gear operators.

DYNATORQUE Quarter-Turn Stainless Steel Gear Operators


Model Unit Weight, lbm Max. Output Torque, Gear Ratio Turns for 90° Std. Output Bore, in
Std. Key Size, in × in Std. Mounting Pattern
(Qty. and Size)
Std. Mounting Pattern
(Bolt Circle)
Mech. Adv.
Handwheel Size, in
Approx. Rim Pull, lbf
DT3 8 4,500 30:1 7.5 1.000 0.250 (4)3/8-16
DT7 14 10,000 48:1 12 1.750 0.375 (4)1/2-13
DT21 33 26,000 60:1 15 2.500 0.500 (4)5/8-11
 5.512 13.20


  • Handwheels listed are recommended sizes to produce full rated torque with the rim effort listed.
  • Bore, keyways, and mounting patterns listed are for Cameron standards.
  • Standard mounting patterns on the DT2 and DT5 are (4) tapped holes straddling centerline at 45°.