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HYW Hydraulic Sheer Actuator

The Type HYW Hydraulic Actuator is a ratio-piston-type actuator mounted on a reverse-acting gate valve. The HYW Hydraulic Wire Shear Actuator is designed to be failsafe and fail-close. The coiled multi-spring assembly provides the added shear force. When installed as part of a safety system, it will automatically close with the loss of control pressure and will open automatically when the control pressure is restored. The wire shear actuator becomes the primary surface safety device during wireline operations. Should an emergency take place while the wireline tool string is in the well, the wire shear actuator is designed to shear the wire and seal off the flow of the well.


  • The actuators are used on the secondary master valve. They are the primary surface safety device during a wireline operation.
  • As part of a surface safety system, the actuator will shear the wireline and seal off the flow from the well in the event of a catastrophic event.
  • The HYW surface safety valve is a hydraulically controlled actuator that is operated by a closed hydraulic system completely independent of well fluids and pressure.
  • Hydraulic pressure acting on the piston holds the valve open. Loss of hydraulic pressure in the actuators cylinder allows the well or flowline pressure acting on the area of the lower stems to force the stem and gate closed. The spring package is sized to cut a specific size of wireline.


  • Coiled spring design provides cutting force.
  • Control line port can be rotated 360°.
  • Hydraulic section is resistant to corrosion.
  • Has a quick-disconnect clamp.


  • In the event of a fire, the metal-to-metal seal between bonnet and lower stem acts as a secondary seal if the stem packing is damaged.
  • Has a back-seat test port and packing leak detection port.
  • Spring packages are designed to fit customer application.
  • FMC Surface Wellhead has provided spring packages to cut various-sized wires. We provide a North Sea operator a wire shear spring package to cut 7/16" braided line (shear force required was 22,400 lbs.).
  • Oil port can be rotated 360 degrees for easy alignment of power-source control line.
  • Has a lifting eye to facilitate removing the actuator when mounted horizontally.
  • Two bonnet types are available to cover a wide range of applications. The Type A bonnet is the extended version, and the Type B bonnet is the flush-mounted version.
  • Nipoloy process (electrolysis nickel) is used on hydraulic cylinder and piston for corrosion resistance.
  • Hydraulic piston is hard chromed for corrosion resistance.