Core drilling is a method of drilling that involves using a special drill bit and drill to remove a cylindrical core of material. This technique is often used in construction and other industries to create holes.
[pdf] With interchangeable core bits capable of drilling holes from 1.5" to 9" in diameter, operators can tackle diverse pipe materials including vitrified clay, concrete, ductile iron, cast iron, C-900, HOBAS, and PVC/HDPE systems using a single versatile machine.
[pdf] Both high-pressure mud pumps are utilized on rigs to circulate the drilling fluidaround. Each type, however, has its operating limits,. .
The speed of the piston is not constant during the suction and discharge strokes. During each stroke, the speed increases from zero to maximum at approximately the halfway position. .
Mud pumps must be equipped with pressure relief valves. These valves prevent too high a pressure from being built up in the circulating system. The relief valves most.
[pdf] 
