External sleeve with cage choke

External sleeve moving outside of flow cage type trim uses a flow sleeve moving over the ported cage to control flow.
Metal to metal or tungsten carbide seat design on the outside of the flow sleeve and out of the high-velocity flow area assure a positive shut off and extended seat life.
The controlling element (flow sleeve) moves in a lower velocity regime and leads to the high erosion resistance of this trim design.
Applications of these chokes include high-pressure drops and fluids with entrained solids such as formation sands.
This trim is normally supplied as solid tungsten carbide 4 x 4 geometry gives an equal percentage characteristic.
4 diametrically opposite ports will 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.
The pressure balancing of the trim design reduces the operating torque.
Flow is directed through ports into the center of the trim where it impinges on flow from the opposite port.
Hydro dynamically designed body gallery maximizes flow capacity and minimizes body & outlet erosion.
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 marking in diametrical increments of either 1/32" or 1/64".
Barrel type indicator is used for small trim sizes and micrometer type indicator is used for large trim sizes.
Metal to metal shut off in accordance with ANSI class IV & V.
Cartridge style trim installation uses no internal threads, hence no special tools are required for field maintenance.