Dynatorque 180 memory-stop worm gears

Help a valve or damper return to the same predetermined position when reopened

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For controlled travel up to 180°

Dynatorque™ 180 memory-stop worm gears are designed for valve, damper, and rotary applications that require precise, repeatable positioning beyond standard quarter-turn operation. The infinitely adjustable memory-stop device for controlled travel up to 180° helps return the valve or damper to a predetermined position. The traveling nut module supports accurate travel control and repeatable operation.

Built on a trusted platform, these worm gears combine self-locking performance, robust construction, and mounting flexibility. Standard units are available with common mounting interface dimensions, while custom-machined configurations can be supplied with bores, keyways, and bolt patterns to support direct valve integration.

  • Valves and dampers requiring controlled travel up to 180°
  • Nonrising stem valve applications where repeatable multiturn operation is required without thrust loading
  • Process control installations that require a self-locking mechanical gear operator
  • Applications where the valve or damper must return consistently to a predetermined set point
  • Standard and low-temperature service environments, with additional configurations available for specific application requirements
  • Reliable self-locking performance: Worm gear construction helps prevent back-driving in demanding rotary applications
  • Flexible integration: Standard and custom mounting options support alignment with valve topworks and customer-specific requirements
  • Durable construction: Cast gray iron or ductile iron construction promotes dependable service in industrial environments
  • Application versatility: Availability of multiple model sizes and torque ranges supports a broad envelope of valve and damper requirements
  • Traveling nut module for repeatable valve travel to a predetermined set point
  • Standard mounting dimensions or custom-machined configurations available
  • Precision-machined bores, keyways, and bolt patterns available for direct valve mounting

Specifications

Model Unit Weight, lbm Max. Output Torque, lbf.in Gear Ratio Turns for 180° Standard Bore, in Standard Key Size, in Standard Mounting Pattern
(Quantity) and Size, in
Standard Mounting Pattern
(Bolt Circle Diameter), in
Mechanical Advantage Handwheel Size, in Approx. Rim Pull, lbf
DT3-180 7 4,500 30:1 15 1.000 0.250 (4)
3/8–16
3.250 8.10 14 80
DT8-180 19 8,000 30:1 15 1.750 0.375 (4)
1/2–13
5.000 8.10 24 82
DT12-180 26 16,000 57:1 28.5 2.000 0.375 (4)
1/2–13
4.921 13.68 30 78
DT21-180 34 26,000 60:1 30 2.500 0.500 (4)
5/8–11
5.512 22.50 30 77
DT36-180 78 36,000 53:1 26.5 3.250 0.750 (4)
3/4–10
6.496 19.00 36 105
DT50-180* 105 50,000 212:1 106 3.250 0.750 (4)
3/4–10
6.496 60.80 20 80
DT54-180* 108 63,000 318:1 159 3.250 0.750 (4)
3/4–10
6.496 91.20 18 77

* Units with spur assist

Notes

  • Handwheels listed are recommended sizes to produce full rated torque with the rim effort listed.
  • Bores, keyways, and mounting patterns listed are per SLB standards.
  • Standard mounting patterns on the DT3-180 through DT54-180 are 4 tapped holes straddling the centerline at 45°.