• Patented sliding shuttle/sleeve design automatically adjusts fluid flow to regulate well, casing and drill pipe pressures.
  • Triple, tungsten-carbide wear sleeves provide downstream choke bore protection.
    No-leak shut-in seals (metal-to-metal and Teflon-to-metal).
  • High-capacity, 3-in. (76 -mm) choke bore.
  • Long-life for severe service operations, tungsten-carbide static-trim, reversible dynamic trim, hard-faced (stellite) shuttle assembly and internal removable-body sleeve preventing valve-body erosion.
  • Rated for H2S service.
  • Chrome-plated internal bores for corrosion resistance
    Simple seal replacement
  • Electronic position indicator, computer compatible
    Pre-set maximum pressure capability
  • Control console includes digital pump stroke counters with rate meter, stop watch and clock


  • Easy, predictable standpipe pressure control
    No-leak shut-in
  • Precision control for for MPD and UBD techniques when controlling backpressures minimizing lost circulation, gas intrusion, fluid costs, production damage and blowouts
  • Self-cleaning orifice reduces plugging
  • Easy-to-maintain internal components
  • Tungsten carbide or stellite-coated internal wear parts are all replaceable and more durable than needle-valve chokes

This information is supplied solely for informational purposes and ECD Management makes no guarantees or warranties, either expressed or implied, with respect to the accuracy and use of this data. All product warranties and guarantees shall be governed by the Standard Terms of Sale. Nothing in this document is legal advice or is a substitute for competent legal advice.

Our automated MPD choke provides easier, more precise well pressure control, and serves as the only true pressure­ balanced choke in the market.

The AutoChoke design allows the safe and efficient implementation of managed pressure drilling (MPD) practices under all conditions. Choke operators no longer have to fight the controls during transition operations, such as mud pump start-up or shut-down, making or breaking connections, or when mud and gas are flowing alternately through the choke.

How it works

The unique design of the AUTOCHOKE unit incorporates a sliding shuttle which is connected to a dynamic-trim sleeve . This shuttle assembly slides back and forth into a matching static-trim sleeve, forming a circular orifice, controlling the flow of fluid or gas from the well. The hydraulic set-point pressure, applied to the back side of the shuttle assembly, is adjusted by the set-point pressure regulator and is measured by the hydraulic set-point gauge located on the choke control panel. Casing pressure is applied to the front side of the shuttle assembly.

Fully Closed

When the choke is completely closed for positive choke manifold testing, a no-leak condition is maintained by both a metal-to-metal and a Teflon-to-metal seal.


Either an increase in casing pressure or a decrease in hydraulic set-point pressure causes the shuttle assembly to move, increasing the size of the orifice. This allows fluid or gas to flow from the well, decreasing the casing pressure until it equals the hydraulic set-point pressure.


Either a decrease in casing pressure or an increase in hydraulic set-point pressure causes the shuttle assembly to move, decreasing the size of the orifice . This reduces fluid or gas flow from the well, increasing the casing pressure until it equals the hydraulic set-point pressure.

Standard Operating Position

In this position, the dynamic-trim face is barely past the static-trim face, automatically controlling the casing pressure of the well. As casing pressure changes, the shuttle assembly adjusts to balance the pressure on both sides of the shuttle.

Passing Debris

Debris that plugs the orifice increases the casing pressure. This causes the shuttle assembly to move and increases the size of the orifice, allowing the debris to be discharged while maintaining good pressure control. The choke is designed to accommodate considerable buildup in the housing before a manual clean-out operation is required. These features are ideal for maintaining desired casing pressures during MPD operations.


  • 3.06-in (78 mm) API inlet and outlet flanges
  • 10.5 in (267 mm) from inlet flange face to outlet flange centerline x 15 in (381 mm) from outlet face flange to inlet flange centerline for 10,000 psi choke; 13.5 in x 16.75 in for 15,000 psi choke
  • Temperature rating : -20 to 250° F (-29 to 121° C)
  • Bore size: 3 in (76 mm)
  • Manufactured in accordance with API 6A 17th edition PSL3, Temperature Class P to U, Material Class EE and NACE MR-01-75