FLUID TREATMENT SYSTEM

摘要

A water treatment system having a reverse osmosis unit (14) includes a storage tank (40) having an outer tank housing (42) that encloses an expandable bladder (50). A pressurized region (62) is defined between the outside of the bladder (50) and inside of the housing (42). A control valve assembly (44) controls communication of source water under pressure to pressurizing region (62) and communicates the region (62) with a drain (22). The assembly (44) includes a pilot valve (70) that is responsive to a state of dispensing and includes a valve element (76) that moves between a first dispensing position and a second non-dispensing position. A servo valve (72) is responsive to position of the pilot valve (70) and communicates source water under pressure to the region (62) when the pilot valve (70) is in the first position thus applying pressure to bladder (50) to expel treated water and communicates region (62) to the drain (22) when dispensing is not occurring so as to allow bladder (50) to expand as it receives treated water from the reverse osmosis unit (14).