A master
bushing fits inside the turntable of a rotary table, the turntable rotates the
master bushing. The master bushing has an opening through which crew members
run pipe into the wellbore. A tapered insert bowl fits inside the master bushing and
suspends the pipe off the well bottom when the pipe and bit are not rotating.
The tapered bowls sizing from 17.1/2 to 49.1/2inch. They are cast with
high-quality alloy steel and the sizes conform to API Spec 7K. There are two
types of master bushing, pin drive and square drive accordingly. API standard
rotary slips, drill collar slips, casing slips and roller kelly bushings can be
contained in them.
