Boart Longyear

Duplex Drilling Flushing Heads

Duplex drilling flushing heads allow for the introduction of flushing media into the drill string as well as an exit point through the flushing bell. Flushing heads are selected to match the shank on the hydraulic drifter, the casing diameter and thread, and the type of inner drill rod being utilized.

Our duplex flushing heads are modular in design, enabling you to keep the same flushing body and flushing ring but allowing you to change the balance rod and ejection bell for different sizes of casing and inner rods being utilized. Duplex drilling flushing heads for alternate casing sizes, inner rod types and hydraulic drifter shanks are available upon request.

Components used in and with the Drive Drilling Flushing head include the following.

Flushing body
One end of the flushing body has a female thread to match with the hydraulic drifter shank. The other end of the flushing body has a female thread to match the balance rod as well as a male thread to match the flushing bell.
The patented TwinDrive™ thread is used for both the balance rod and flushing bell. The TwinDrive thread makes it easier to unscrew the balance rod or flushing bell and is better at withstanding the percussive forces from the hydraulic drifter.

Flushing ring and seals
The flushing ring is held stationary by the mounting bracket fixed to the drifter while the flushing body rotates. The flushing ring is the connection point for the flushing hose and has upper and lower lip seals to contain the flushing media.

Flushing bell
The flushing bell has either a female TwinDrive™ thread or a female rope thread to mate with the flushing body and a female thread to match the casing being used in the drill string. Flushing media exits the drill string through the flushing bell. A threaded plug is provided with the flushing bell to block off the return flushing flow and force circulation via the outside of the casing through the annulus to the surface.