Third Generation. BK-FX was designed for Frac Strings unlike first generation designs which were primarily for drilling with casing in shallow vertical wells. Tapered OD bevels reduce friction through horizontal sections. BK-FX, BK-HT and BK are interchangeable.
Buttress Compatible. BTC compatible for cost savings on hangars, float shoes, float collars, crossovers and custom tools.
Thicker Coupling with Integral Shoulder. Made from thicker coupling stock, the BK-FX has an integral shoulder to eliminate coupling turning that is possible with many semi-premium connections.The BK-FX will have lower
coupling stresses if the connection is inadvertently over-torqued.
Better Buttress Sealing. Uses a modified buttress thread for tighter thread sealing and pin nose seal stabilization. The thicker coupling is ideal for high collapse or enhanced burst strength pipe. The BK-FX allows the use of corrosion resistant control yield couplings with the higher yield pipe.
Strength. Pin nose to box shoulder contact allows for higher bending loads and structural compressive loads while maintaining sealing. A low hoop stress design and thicker coupling reduces the chance of coupling splits and leaks from high frac pressures. The smooth premium pin nose bore is tapered with edge breaks to prevent hang ups.
Over-Torque. The BK-FX has better over-torque characteristics which will keep the coupling intact and provide better chance of drift-ability past
yield. Hoop stress in a slightly salty, acidic, or sour environment is detrimental. Because of its low hoop stress a BK-FX will remain intact.
Fast and Consistent Shoulder Torque Installation Better threading techniques and coupling coatings allow for quick low cost installation. The BK will run quickly, reducing the run time per well. A lower shoulder torque ensures that optimum sealing is achieved on the pin nose seal.
High RPM Fatigue Resistance from Low Stress Runout Threads The BK-FX uses the field proven buttress thread with low stress runout threads to extend the time it can be rotated through a dogleg at high RPM.