The rotary drilling hose (API7K) is the flexible connector between the top of the standpipe and the swivel that allows for vertical travel. Its lengths are in the range of 45 ft (13.7 m) and over. We generally use rotar.
[pdf] If the hydrostatic head of the drilling fluid is insufficient to control subsurface pressure, formation fluids will flow into the well. To maintain well control, back pressure is applied by routing the returns throug.
[pdf] The rotary drilling hose (API7K) is the flexible connector between the top of the standpipe and the swivel that allows for vertical travel. Its lengths are in the range of 45 ft (13.7 m) and over. We generally use rotar.
[pdf] 
