Definition - What does Exit Angle mean?
Exit angle is the angle at which a drill bit exits a pilot hole in a horizontal directional drilling operation. It is one of the design consideration in trenchless construction, along with the entry angle. The typical exit angle is 5 to 12 degrees.
Trenchlesspedia explains Exit Angle
Horizontal directional drilling involves the excavation of a pilot hole, reaming the hole to the appropriate size, and installing pipe through the hole. The line that the drill string follows often includes a steady descent below the earth, then advancement parallel to the ground, followed by a steady incline back to the surface. The angle of this incline to the exit point of the pilot hole is called the exit angle.
Every horizontal drilling operation is different. Sometimes there are obstacles to be avoided. Modern trenchless equipment and techniques enable workers to complete challenging excavations successfully. Each excavation should be carefully planned in advance. Among the design specifications is the exit angle. An angle that is too steep could cause problems with the final construction.