Digger Differential fill-up Float Shoe allows 90% casing fill-up during run-in, reducing surge pressures caused by the piston effect of running in restricted I.D. Use of differential shoe provides additional buoyancy by allowing only 81% casing fill-up further enhancing works efficiency. Circulating 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. After allowing sufficient time for ball to reach the equipment conversion can be achieve by applying approximately 600-800 psi of pump pressure (adjustable).
Available sizes 4 ½” to 20” and any special sizes can be custom made as required.