| 摘要 |
A flow restrictor comprising a body adapted to restrict a flow of fluid through a drill rod passage, the body having a coupling for coupling said body into the drill rod passage, said body defining an upstream fluid receiving passage, a downstream fluid egress s passage, and a passage of restrictive diameter between said passages to limit the flow of fluid in the drill rod passage. 30109501 (GHMatters) P88808.AU 20/12/11 NN t '-4L |
