Flow couplings are used to protect the integrity of tubing
from erosive turbulence. They are also used above and
below a geometric restriction in the flow path,
depending on the well conditions. API Recommended
Practices 14B advises use of flow couplings above
and below safety valves.
Baker Hughes offers flow couplings in 4-ft.
(1.22-m), 6-ft. (1.83-m), 8-ft.
(2.45-m) and 10-ft. (3.05-m) lengths to suit the application.