| 摘要 |
A magnetically operated flow device contains a flow responsive magnetically attractable body within a flow passage defining upstream and downstream directions therein. The body is movable in upstream and downstream directions in the passage. The passage includes upstream and downstream limit positions to define upstream and downstream limits of movement of the body within the passage. Magnetic means are provided to attract the body against the fluid flow within the passage to the upstream limit position. The body constitutes a drag obstruction to fluid flow through the passage and will, therefore, decouple from its upstream magnetically retained position in the passage and move to the downstream limit position when drag forces (i.e. flow) increase to the design limit value. 19 |
