Reverse osmosis water-on-water control valve

A reverse osmosis water-on-water valve comprising:

• a valve feed inlet port, a valve feed outlet port, a drain port, a reject port, and a tank squeeze port, wherein the valve has at least three states, wherein:
• in the first state, a first fluid path is defined by the valve feed inlet port that is in fluid communication with the valve feed outlet port, and a second fluid path is defined by the reject port that is in fluid communication with the tank squeeze port;
• in the second state, a third fluid path is defined by the valve feed inlet port that is in fluid communication with the valve feed outlet port, and a fourth fluid path is defined by the tank squeeze port that is in fluid communication with the drain port;
• and
• in the third state, the valve feed inlet port is not in fluid communication with the valve feed outlet port;
• wherein the valve is a shuttle valve comprising a piston body in a housing, the piston body having a first end portion connected to a spring;
• and
• wherein the piston body comprises a plurality of sections, a first group of sections each independently having a solid surface effective to block flow from or to one or more of the following:
• the tank squeeze port depending on the state of the valve, and a second group of sections each independently having a plurality of channels comprising linear grating or spiral grating to define the plurality of channels effective to permit flow from or to one or more of the following:
• the valve feed inlet port, the valve feed outlet port, the drain port, the reject port, and the tank squeeze port depending on the state of the valve.

A filtration system comprising:

• a water-on-water storage tank comprising a squeeze side and a product side separated by a membrane;
• a filter module in fluid communication with the water-on-water storage tank, a feed source, a product outlet, and a drain outlet;
• a feed line connecting the feed source to a feed inlet of the filter module;
• a product line connecting a filtrate outlet of the filter module to the product side of the storage tank and the product outlet;
• and
• a drain line connecting a reject outlet of the filter module to the squeeze side of the storage tank and the drain outlet of the system;
• and
• a shuttle valve comprising a piston body having a first end connected to a spring, a second end having a piston face, and a plurality of ports that regulates the flow from the feed source, wherein pressure in the product line on the piston face determines the state of the shuttle valve and wherein the piston body has a diameter that is substantially the same along its length and contains gratings forming channels acting as flow channels to facilitate fluid communication between various flow ports.

A reverse osmosis water-on-water valve comprising:

• a shuttle valve having a piston body in a housing;
• the piston body having a first end portion connected to a spring, and a second end portion having a piston face;
• the second end portion enclosed in a chamber in fluid communication with a product line;
• the piston body having a diameter that is substantially the same along its length and contains gratings forming channels to facilitate fluid communication between various flow ports;
• and the housing having a drain port, a reject port, and a tank squeeze port, and wherein pressure in the product line acting on the piston face moves the piston body.