Wellhead Inc has developed a drilling flange for it’s independent wellhead line.  This flange provides a safer working environment & longer life than conventional drilling flanges.  

Quick Lock Drilling Flange

The New Quick Lock Drilling Flange Provides a Quick and Safer Way to Nipple up the BOP Stack. Speed The BOP Is Bolted to the Drilling Flange and Remains Attached Throughout the Drilling Campaign.  A Threaded Bushing Is Threaded Onto WHI’s W92 Casing Head.  The Bushing Helps Guide the Drilling Flange Onto the Casing Head.  Once the Drilling Flange Is Resting on Top of the Casing Head the Hammer Nut Is Tightened, Securing the BOP in Place Eliminating the Need to Hammer Tight Each Individual Stud As Is Normal. Safety Full Thread Engagement Between the Threaded Bushing and the Casing Head Is Achieved Every Time.  With Conventional Flanges It Is Impossible to Have Full Threaded Engagement Because the Drilling Flange Shoulders Out on the O-ring Face Seal.  Takes One Man in the Cellar to Tighten the Drilling Flange.