| 摘要 |
A water purification system comprising a reverse osmosis unit (50) to separate feed water as product water and waste water, a reservoir (90) having bladder controlled expandable and contractible product water and control water chambers (94, 95, 96) and a control valve subsystem. The control valve subsystem includes a feed water shut-off valve (10) and a regulating valve (30). The shut-off valve (10) has a control chamber (20) subjected to product water pressure to control its open-closed condition, and is effective to close it at a predetermined upper limit of product water pressure. The regulating valve (30) includes two diaphragm areas (A1, A2) on a single moving element, two diaphragm operated valves (37, 38) (only one of which can be open at one time), and a relief valve (46). The regulating valve (30) is responsive to a demand for bladder control water to the reservoir (90) on diaphragm area (A1) to establish a first and higher level of control water flowing to the reservoir (90), and is also responsive to an excess of bladder control water flowing from the reservoir acting on diaphragm areas (A1) and (A2) to establish a second and lower level of control water back pressure in the reservoir (90). |
