Differential fill-up float equipment allows 90 percent casing fill-up during run-in, reducing surge pressures caused by the piston effect of running-in restricted IDs. Use of differential collar with shoe provides additional buoyancy by allowing only 81 percent casing fill-up further enhancing draw works efficiency.

Circulation can be established at any time while running-in. Dropping a ball converts the differential valve to a regular back-pressure valve. When collar and shoe are run together, dropping one ball converts both units.

The operation of the stage collar requires only the plugs that come with the collar and the manipulation of casing pressure. A rubber seal-off plate is also provided to place in the top float collar only when the plug bumping surface is flat. The nose of the Model "D" flexible wiper plug is tapered to guide through the stage collar and needs a beveled surface on which to seat and seal.

The Model "J" stage collar covers casing sizes 4-1/2 in. through 9-5/8 in. Threads and materials specifications vary to meet operators casing program.

• Strong one-piece body construction.
• Protected closing sleeve.
• Inner sleeves locked against rotation.
• Full, smooth bore after drill out.
  
  BENEFITS
  
• No internal threaded or welded pieces to leak or fail.
• Nothing to snag packers or running tools run subsequently.
• Easily drilled-out sleeves and plugs are rubber and
  aluminium.
• Simple hydraulic operation.
• Shut-off sleeve cannot be accidentally reopened.