Internal plug with cage - single stage choke
- Internal plug moving in-side of a cage designed for single stage pressure drop control choke was designed for economical and dependable means of controlling flow and pressure in a wide range of oilfield applications.
- This choke uses a plug moving inside a ported flow cage to adjust the area open to flow and thereby controls pressure drop in the valve and flow rate.
- The flow cage is designed in such a way that flow is split into a number of streams which are directed through the ports in the flow cage and onto themselves. Energy is dissipated by the flow impinging in the center of the flow cage and erosion is reduced because the flow is accelerated onto itself and no other components such as the outlet to the choke.
- Hydro dynamically designed body gallery maximizes flow capacity and minimizes body & outlet erosion.
- Adjustment is made by means of a rotating hand wheel in direction marked on it. This movement, in turn, raises or lowers the stem of choke.
- Standard trim with a 4 x 4 port flow profile. 4 diametrically opposite ports provide the highest wear resistance in a 'cage' type flow trim. 4 small ports in the lower section provide fine control needed at low openings while 4 larger ports provide capacity for higher flows.
- Trim uses a solid plug with pressure balancing holes moving inside a ported cage to control flow.
- Flow cage is supported at both ends by the body and pressure balance sleeve respectively thereby providing a rigid and robust design.
- Metal to metal shut off in accordance with ANSI class IV & V.
- Bonnet design available in both options hammer union type and bolted type.
- Dynamic seal (stem packing) with spring energized seals.
- Linear non-rotating stem movement increases stem packing life.
- Position indicator calibrated in 1/64" bean size.
- Barrel type indicator is used for small trim sizes and micrometer type indicator is used for large trim sizes.

4X4 Hole Geometry

Indicator

Pressure Balance Seal

Stem Lock Assembly

Stem Packing