| 摘要 |
Simple APCV, ADPCV and PICV's are provided. The APCV's are referenced to the atmosphere and control the gauge pressure, either upstream or downstream. The ADPCV's are the same as t he APCV's, differing in that they are not referenced to the atmosphere. They are instead referenced to a second point in the flui d flow system and control the differential pressure. The PICV's are control valves connected in series with ADPCV's and control the fluid flow rate through the valve independently of variations in the line pressure. A preferred APCV has a valve body (1) with connections for a single-phase fluid line and a flow passage between the inlet (2) and the outlet (3) of said fluid line, with an opening having a defined seat orifice (7) intersecting the flow passage. A moveable assembly, comprising a disk (5) or cup is connected to a pressure sensing member (4), having essentially the same effective surface area. The moveable assembly, is biased by a force , and is free to automatically move to any intermediate position between fully open and closed, producing a desired outlet pressure which minus the reference pressure, times the effective surface area of the disk or cup generates an opposing force equal to the biasing force. |
