| 摘要 |
<p>A fluid flow control device having a sleeve and sleeve guide axially movable relative to each other but biassed by spring means in one direction, and control slots formed by the sleeve and sleeve guide to control flow to a piston and to a port, wherein at a threshold flow rate the piston is moved towards the port and at a flow rate above the threshold relative movement between the sleeve and the sleeve guide maintains substantially constant the fluid pressure drop across primary slot means of the control slots and also meters flow to the piston via metering slots of the control slots, whereby the piston closes the port after a required flow of fluid.</p> |
