DYNATORQUE D-Lock Valve-Locking Device | SLB


Valve-locking device

DYNATORQUE accessories during manufacturing.

The DYNATORQUE D-Lock valve-locking device is used with automated valves (pneumatic, hydraulic or electric) that require "lockout" capability to prevent valve rotation. This feature is ideal for applications such as maintenance shutdowns, when the valve must remain in a locked position even if an actuator is unintentionally engaged. The DYNATORQUE D-Lock device is suited for applications where actuators must be locked in either the full clockwise or counter clockwise positions (i.e., locked open or locked closed).

The device

  • provides lockout capabilities for all types of valve and other rotational devices and is especially effective when the valve requires a constant torque load to prevent leakage (i.e., such as torque-seated butterfly valves)
  • holds valve in either open or closed position while compensating for hysteresis and machining tolerances (select models provide both open and closed locking)
  • is ideal for torque-seated valves such as triple offset butterfly valves
  • is applicable for almost any rotating device.

Application torque requirements must be accurately calculated for correct DYNATORQUE D-Lock device sizing. The devices are totally enclosed, weather-resistant, and permanently lubricated. They are designed to mount between the valve and the actuator.

Valve-locking device
Unit Weight, lbm Max. Valve Actuator Torque, in.lbf Gear Ratio Turns for 90° Standard Output Bore Standard Key Size Standard Mounting Pattern (Quantity and Size) Standard Mounting Pattern (Bolt Circle Dia.)
13.5 3,000 30:1 7.5 1.250 0.25 × 0.18 (4)5/16-18 2.756
12 39 12,000 57:1 14.25 2.000 0.375 × 0.375
(4)1/2-13 4.921
21 56 21,000 44:1 11 2.500 0.500 × 0.500
(4)5/8-11 5.512
36 111 63,000 53:1 13.25 3.250 0.750 × 0.750
(8) 5/8-11 6.496
60 207 140,000 60:1 15 4.000 1.000 × 1.000
(8)5/8-11 10.000
260 672 260,000 100:1 25 6.250 1.50 × 1.00 (8)1 1/8-7 14.016


  • Mechanical advantage is not required because the lockout position of the valve is reached using the powered device. The gears in the DYNATORQUE D-Lock device move its output to the lock position under no-load conditions.
  • The device can be operated with a standard 3/4-in socket, box end, or adjustable wrench. (These tools are not supplied as part of this lockout package.)
  • The device is not field adjustable. It must be ordered as "lock clockwise" or "lock counterclockwise." Provisions must be made to prevent each component in the valve automation package from rotating independently. All components should be pinned together at assembly to prevent inadvertent rotation.
  • If automated valve accessories are installed in corrosive atmospheric environments, please give consideration to using stainless steel drivers instead of standard carbon steel drivers.