Patent Publication Number: US-2023151592-A1

Title: Backflow preventer for water filtering equipment

Description:
BACKGROUND of INVENTION 
     Field of Invention 
     The present invention relates to water filtering equipment, and more particularly to a backflow preventer for water filtering equipment. 
     Description of the Related Art 
     Rapid industrial development nowadays has relatively caused excessive pollution of air, land, and water sources. Although tap water undergoes precipitation, disinfection, and insolation procedures in the water purification plant before it is delivered to each user, these procedures cannot completely remove all kinds of pollutants, and it will endanger health when used. In order to ensure the safety of water, many people use all kinds of the water filtering equipment to filter the water before using it. Many of the water filtering equipment employs reverse osmosis (RO) water purifier. 
     The RO water purifier currently known has several filtering units, the filtering unit comprises the filter, the RO membrane and the pressure tank, the filtering unit is provided with the connector, so that the connector can be connected through the water pipes. Therefore the filtering unit is connected to each other, and the connector can be used to connect the water source. The water supplied from the water source is filtered through the filter unit and the RO membrane to produce pure water. At the same time, various impurities and harmful substances that cannot penetrate the filter element and the RO membrane when the concentrated waste water is discharged. 
     However, the above-mentioned conventional structure still has the following problems in practical applications: the connector can only provide water to pass through, but has no backstop function. Therefore, if water backflow occurs during water production, it may cause the filtering unit being damaged, and the pure water is mixed with waste water. 
     Therefore, it is desirable to provide a backflow preventer for water filtering equipment to mitigate and/or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     An objective of present invention is to provide a backflow preventer for water filtering equipment. 
     To achieve these and other objects of the present invention, A backflow preventer for water filtering equipment, the water filtering equipment has a plurality of filtering units, the filtering units connected among each other via at a plurality of connectors connected by at least one hose and connected to a water source via the at least one of the connectors, and at least one of the connectors has a check valve set, and the check valve set has a check valve and an unidirectional valve. The check valve has an elastic tube with a duckbill valve at one end and is connected to a base at another end, and the base has a socket sleeved onto the elastic tube. The unidirectional valve has a first main portion with a larger diameter and a second main portion with a smaller diameter, the diameter of the second main portion corresponding to an inner diameter of the socket of the check valve; after the check valve is placed in the first open end of the connector, the second main portion of the unidirectional valve is inserted into the socket of the check valve; and the unidirectional valve further has a through aperture passing through the first main portion and the second main portion. 
     Other objects, advantages, and novel features of invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a three-dimensional drawing of the water filtering equipment of a preferred embodiment according to the present invention. 
         FIG.  2    is a three-dimensional combination drawing of the connector and the check valve set of according to the preferred embodiment of the present invention. 
         FIG.  3    is a three-dimensional exploded view of the connector and the check valve set of according to the preferred embodiment of the present invention. 
         FIG.  4    is a sectional view of the combination of the connector and the check valve set being opened according to the preferred embodiment of the present invention. 
         FIG.  5    is the state drawing of the valve of according to the preferred embodiment of the present invention. 
         FIG.  6    is the backstop state diagram according to the preferred embodiment of the present invention. 
         FIG.  7    is a drawing of another preferred embodiment according to the present invention. 
         FIG.  8    is a three-dimensional exploded view of another preferred embodiment of the present invention. 
         FIG.  9    is a combined cross-sectional view of another preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     First, please refer to  FIGS.  1 - 4   . A water filtering equipment  10  comprises a plurality of filtering units  11 , and the filtering units  11  are connected among each other via at a plurality of connectors  20  connected by at least one hose  21  and connected to a water source via the at least one of the connectors  20 . Furthermore, at least one of the connectors  20  has a check valve set  30 , and the check valve set  30  has a check valve  31  and an unidirectional valve  32 . The connector  20  has a first open end  201  and a second open end  202 , the first open end  201  is an input end, and the second open end  202  is an output end. The first open end  201  is configured for being coupled with the check valve set  30 . The check valve  31  has an elastic tube  311 , and the elastic tube  311  has an elastic tube with a duckbill valve  32  at one end and is connected to a base  313  at another end. Moreover, the base has a socket  314  sleeved onto the elastic tube  311 . The unidirectional valve  32  has a first main portion  321  with a larger diameter and a second main portion  322  with a smaller diameter, and the diameter of the second main portion  322  is corresponding to an inner diameter of the socket  314  of the check valve  31 . After the check valve  31  is placed in the first open end  201  of the connector  20 , the second main portion  322  of the unidirectional valve  32  is inserted into the socket  314  of the check valve  31 . Furthermore, the unidirectional valve  32  further has a through aperture  323  passing through the first main portion  321  and the second main portion  322 . With the diameter of the through aperture  323  is significantly smaller than the diameter of the elastic tube  311  and the installation of the check valve  31 , a backflow prevention can be achieved. 
     Moreover, the water filtering equipment  10  is a reverse osmosis (RO) water purifier, and the filtering unit  11  is a filter, a RO membrane, or a pressure barrel 
     Also, the check valve set  30  is configured for being installed in the connector  20 . 
     Furthermore, the check valve set  30  is mounted on the at least one of the connectors  20  for connecting to the water source. 
     In addition, at least one of the connectors  20  is a quick disconnect connector, as shown in  FIG.  1    to  FIG.  6   , so the hose  21  is able to be installed quickly. 
     Additionally, the at least one of the connectors  20  is a locking connector, as shown in  FIG.  4   , so the hose  21  is able to be screwed on the connector  20 . 
     Furthermore, the second main portion  322  of the unidirectional valve  32  is secured with the socket  314  of the check valve  31 . 
     Moreover, the elastic tube  311  of the check valve  31  further has a protruding stopping ring  315 . 
     Additionally, the valve  312  of the check valve  31  is elongated as shown in  FIG.  8    and  FIG.  9   . 
     Besides, the check valve  31  is made of rubber, and the rubber has an 80 Shore A hardness. 
     In actual use, since the check valve set  30  is plugged and secured in the first open end  201  of the connector  20 . When the water source is fed into the through aperture  323 , a forward hydraulic pressure with the elasticity provided by the check valve  31  allows the valve  312  to be opened smoothly, as shown in  FIG.  5   , so that the water can then flow from the valve  312  to the second open end  202 . When the water reverses its flow, the valve  312  is affected by the reverse water pressure and closes immediately, as shown in  FIG.  6   , which effectively stops the reverse flow and prevents the water from flowing back in the reverse direction. When the reverse water pressure is too high, the valve  312  is forced to open, the unidirectional valve  32  combined with the check valve  31  can prevent the check valve  31  from being flushed away from the connector  20  due to the high pressure generated by the reverse flow of water, also because the through aperture  323  has a significantly smaller diameter than the diameter of elastic tube  311 , which produces a higher pipe resistance at the through aperture  323  when the water flows backwards to prevent the water from breaking through the through aperture  323  in the reverse direction. 
     The above mentioned backflow preventer for water filtering equipment has the following advantages: 1. The installation of the check valve set  30  can prevent the water backflow during the use of the water filtering equipment  10 , so that the water quality can be ensured, and it can also prevent the water filtering equipment  10  from being damaged due to the backflow of water. 2. The check valve set  30  uses the check valve  31  and the unidirectional valve  32  to cooperate with each other to maximize the anti-backflow effect and prevent the high water pressure caused by backflow pushes the check valve  31  away from the connector  20 . 
     Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of invention as hereinafter claimed.