Pneumatic Diaphragm Actuator DX


Omni Model DX pneumatic diaphragm actuators are designed to operate surface safety or shutdown valves on oil & gas wellhead, transmission, storage, manifold or other applications where fail-safe capability is required. 

Model DX actuators can be used for land or off shore installations and are engineered to provide reliable service in a variety of operating conditions.

Omni can provide Model DX actuators already mounted on valves and ready to deploy, or as actuated bonnet assemblies ready to mount on valves from other manufacturers.

Additionally, Omni offers a full range of accessories including standard & fusible manual overrides, position indicators and fusible lock open devices.



Model DX actuators can be adapted to operate valves from any manufacturer (interface information is required) and can be assembled in single or tandem (double actuator) configurations if required by field conditions.

Over-Pressure Protection

Model DX actuators come equipped with pressure relief devices to protect personnel and guard against damage to the actuator in case of an over pressure condition. The pressure relief device is easily inspected and is field-replaceable.

Orientation, Rotation & Ease of Piping

Model DX actuators have pressure inlet and outlet ports located at an angle in the top plug assembly to facilitate proper piping orientation based on field conditions. Once proper orientation has been achieved, the actuator’s lower bonnet retaining ring can be locked into place to prevent accidental rotation of the actuator while in service.

Backseat & Packing Integrity

Model DX actuators incorporate bonnet assemblies that have an integrated metal-tometal backseat. A bonnet fitting can also be used to relieve any pressure that might be trapped between the backseat and stem packing after the backseat operation. A tattletale weep port is located above the packing to provide visual confirmation of stem seal integrity during operation. All Model DX ports can be used to pipe fugitive
emissions to a containment vessel, if required.

Corrosion Protection

Model DX actuator housings are internally and externally coated to prevent corrosion due to environmental conditions. All internal components are either stainless steel or are coated to prevent corrosion due to any contamination that might be present in the control pressure source.


Model DX actuators are lightweight and designed for ease of maintenance. All non-metallic seals and other parts are easily replaceable.

Available Sizes

Model Size Stroke
DX 10 10” Up to 2 1⁄16” bore
DX 12 12” Up tp 3 1⁄8” bore
DX 15 15” Up to 4 1⁄16” bore
DX 18 18” Up tp 5 1⁄8” bore
DX 20 20” Up to 4 1⁄16” bore