| http://www.w3.org/ns/prov#value | - Ball valve 5 is kept in the open position to allow hydrocarbons to flow freely up inner passage 9 to surface.In one embodiment of the present invention, the inner pipe or tube of the concentric drill pipe or concentric coiled tubing is preferably made from a pliable, conductive material such as rubber, rubber/steel, fiberglass or composite material, capable of withstanding the forces and pressures
|
