Abstract: This application discloses an ultra-low flow limiting device, which includes: a flow limiting seat formed as a rigid structure, an inner wall thereof forming a stepped structure, an incoming water area being formed above a top surface of the stepped structure, an outgoing water area being formed below the top surface of the stepped structure; a flow limiting plate formed as a deformable structure, forming a surface contact with the top surface of the stepped structure and covering a first flow channel; and the first flow channel formed on the top surface of the stepped structure and communicable with the incoming water area and the outgoing water area. The flow limiting plate is deformable under pressure of a fluid and partially fills the first flow channel, and the fluid flows out of the outgoing water area from the incoming water area through the first flow channel.

Abstract: A dual-tank control valve structure includes a main valve assembly connected to an auxiliary valve assembly by an upper opening connector and a central tube connector. The main valve assembly comprises: a valve body where a regeneration piston cavity and a switching piston cavity are formed. The regeneration piston cavity is sequentially divided into multiple cavities, and the endmost cavity communicates with the endmost switching cavity. The switching piston cavity is sequentially divided into multiple cavities; a switching piston is inserted into a first switching piston cavity; a regeneration piston is inserted into a first regeneration piston cavity; a water inlet communicates with a certain switching cavity; a water outlet communicates with another switching cavity; a drainage port communicates with a certain regeneration cavity; and a tank body connecting base is connected to the valve body and communicates with a second and a sixth switching cavity.

Abstract: A dual-tank control valve structure includes a main valve assembly connected to an auxiliary valve assembly by an upper opening connector and a central tube connector. The main valve assembly comprises: a valve body where a regeneration piston cavity and a switching piston cavity are formed. The regeneration piston cavity is sequentially divided into multiple cavities, and the endmost cavity communicates with the endmost switching cavity. The switching piston cavity is sequentially divided into multiple cavities; a switching piston is inserted into a first switching piston cavity; a regeneration piston is inserted into a first regeneration piston cavity; a water inlet communicates with a certain switching cavity; a water outlet communicates with another switching cavity; a drainage port communicates with a certain regeneration cavity; and a tank body connecting base is connected to the valve body and communicates with a second and a sixth switching cavity.