The Rebco BT Circulating Choke Bottom Sub-Assembly is designed for use with both BF and BR Landing Nipples and covers seal bore sizes from 1.78" to 2.81". For use with a BF Landing Nipple, it is paired with a Lock Mandrel ROTW, using an API Cross Over Mandrel or a Packing Mandrel with a BB Seal Unit. For use in a BR Landing Nipple, it is paired with Lock Mandrel ROTZ, using the same API Cross Over Mandrel or Packing Mandrel and BB Seal Unit configuration. The key distinction between the BT and the BB is the addition of a Type BT Bean, which restricts fluid flow through the assembly to a specific calibrated orifice size. The BT permits circulation from above, while the Flow Bean controls the rate of fluid passage through the sub-assembly. Flow Beans can be ordered to a specific ID in 1/64" increments, providing precise flow restriction to the operator's requirements.

The BT consists of six components: a Seal Unit, an API Cross Over Mandrel, two O-Ring Seals, a Type BT Bean, a Spring, and a Type B Cage. Other circulating bottom types, including BR and BP, are available on inquiry. Part numbers and full engineering data are referenced in Section XVI (Plug Chokes).

How to Order: Product Code 21. Specify Landing Nipple type (BF or BR), Lock Mandrel type (ROTW for BF, ROTZ for BR), Bean ID in 1/64" increments, material, and service conditions. Refer to Section XVI for part numbers and engineering data. For BR or BP-type circulating bottoms, contact Rebco directly.