| 摘要 |
The pressure differential metering device of the present invention is generally deployed as a flow restrictor placed in the valve inlet so it will create a desired differential pressure to signal a pilot valve, for example, that drives the main valve to limit the flow rate through the valve. The pressure differential metering device of the present invention is deployed across the valve inlet port, with its central axis perpendicular to the direction of fluid flow. The flow restriction element of the present invention may be configured in a variety of sizes to create a desired restrictive cross section to the flow, thereby creating the required differential pressure signals for the valve instrumentation and control. The flow restriction element is configured with upstream and downstream apertures that are the openings to passageways to the corresponding upstream and downstream end-ports. The end-ports provide connection arrangements for the control system of the main valve instrumentation. |
