Patent Publication Number: US-2023149837-A1

Title: Filter cartridge, and method of retrofitting filter housing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 USC 119 of U.S. Provisional Patent Application No. 63/279,293, filed Nov. 15, 2021, the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD 
     This disclosure generally relates a filter assembly. More particularly, this disclosure relates to a removable filter cartridge in a filter assembly. 
     BACKGROUND 
     Filters can be employed in semiconductor manufacturing to remove contaminants from a fluid. A filter head can direct a fluid (e.g., liquid, water, or the like) through a removable filter. The filter can be configured to remove containment such as, for example, solids as the liquid passes through the filter. In particular, a filter can be used to remove solid containments from a liquid as the liquid passes through the filter. A filter becomes saturated with trapped containments (e.g., solids) over time and is then replaced. Conventionally, the housing of the filter is drained and then removed and replaced with a new filter. 
     SUMMARY 
     In an embodiment, a removable filter cartridge includes a filter housing with an internal volume containing a filter configured to filter a liquid and a sealing valve. The sealing valve includes a first end coupled to an open end of the filter housing and a second end configured to removably couple the removable filter cartridge to a filter head. The sealing valve is configured to be actuated between an open position and a closed position by one of sliding the sealing valve and rotating the filter housing. In the open position, the sealing valve allows liquid flow into and out of the internal volume of the filter housing. In the closed position, the sealing valve seals the internal volume of the filter housing. The sealing valve is configured to be actuated from the open position to the closed position while the sealing valve is removably coupled to the filter head and to maintain the seal while the removable filter cartridge remains uncoupled. 
     In an embodiment, a sealing valve for a removable filter cartridge includes a first end and a second end. The first end configured to be removably coupled to a filter head. The second end is configured to couple the sealing valve to a filter housing to form the removable filter cartridge. The sealing valve is configured to be actuated between an open position and a closed position by one of sliding the sealing valve and rotating the filter housing. In the closed position, the sealing valve seals the internal volume of the filter housing. The sealing valve is configured to be actuated from the open position to the closed position while the sealing valve is removably coupled to the filter head and to maintain the seal while the removable filter cartridge remains uncoupled. 
     In an embodiment, a method of retrofitting a filter housing includes removing the filter housing from a filter head. The removing of the filter housing form the filter head includes uncoupling an open end of the filter housing from the filter head. The method also includes coupling a first end of a sealing valve to the open end of the filter housing to form a removable filter cartridge, and removably coupling the removable filter cartridge to the filter head which includes removably coupling a second end of the sealing valve to the filter head. The sealing valve is configured to be actuated between an open position and a closed position by one of sliding the sealing valve and rotating the filter housing. In the closed position, the sealing valve seals the internal volume of the filter housing. The sealing valve is configured to be actuated from the open position to the closed position while the sealing valve is removably. 
    
    
     
       DRAWINGS 
         FIG.  1    is a front perspective view of an embodiment of a filter assembly. 
         FIG.  2    is an exploded view of the filter assembly of  FIG.  1   , according to an embodiment. 
         FIG.  3    is a top view of the filter assembly of  FIG.  1   , according to an embodiment. 
         FIG.  4 A  is a cross sectional view of a sealing valve of the filter assembly in  FIG.  2    in an open position, according to an embodiment. 
         FIG.  4 B  is a cross sectional view of the sealing valve in  FIG.  4 A  in a closed position, according to an embodiment. 
         FIG.  5    is an exploded view of a valve plate of a sealing valve of a filter assembly, according to an embodiment. 
         FIG.  6    is a cross sectional view of the filter assembly along the line VI-VI in  FIG.  3    in an open position, according to an embodiment. 
         FIG.  7    is a cross sectional view of the filter assembly in  FIG.  6    in a closed position, according to an embodiment. 
         FIG.  8    is a front perspective view of another embodiment of a filter assembly. 
         FIG.  9    is an exploded view of the filter assembly of  FIG.  8   , according to an embodiment. 
         FIG.  10    is an exploded view of a sealing valve of the filter assembly in  FIG.  8   , according to an embodiment. 
         FIG.  11    is a cross sectional view of the filter assembly in  FIG.  8    in an open position, according to an embodiment. 
         FIG.  12    is a cross sectional view of the filter assembly in  FIG.  8    in a closed position, according to an embodiment. 
         FIG.  13    is a block flow diagram of a method of retrofitting a filter housing 
     
    
    
     Like numbers represent like features. 
     DETAILED DESCRIPTION 
       FIGS.  1  and  2    show an embodiment of a filter assembly  1 .  FIG.  1    is a front perspective view of the filter assembly  1 . The filter assembly  1  includes a fluid inlet  2  and a fluid outlet  4 . A fluid to be filtered is supplied to the fluid inlet  2 , is filtered by the filter assembly  1 , and then the filtered fluid is directed out from the fluid outlet  4  of the filter assembly  1 . The filter assembly  1  removes solids from the fluid as the fluid passes through. In an embodiment, the fluid is liquid or mostly liquid. For example, the liquid may be water (e.g., deionized water), HCl, HNO 3 , isopropyl alcohol, or the like. In an embodiment, the fluid is water. The filter assembly  1  includes a removable filter cartridge  10  that is coupled to a filter head  90 . The removed solids remain within the filter cartridge  10 . The filter head  90  includes the fluid inlet  2  and the fluid outlet  4  of the filter assembly  1 . 
     The removable filter cartridge  10  is configured to be removed from the filter head  90 . For example, the removable filter cartridge  10  is removed when due for replacement. The removable filter cartridge  10  may be due for replacement after performing a predetermined amount of filtering. For example, after the removable filter cartridge  10  has filtered predetermined amount of fluid, has filtered a predetermined amount of material from the fluid, has been in use for a predetermined amount of time, has reached a particular saturation of filtered material, etc. 
     The removable filter cartridge  10  includes a filter housing  20  and a sealing valve  40 . The sealing valve  40  is coupled to the filter housing  20  to form the removable filter cartridge  10 . The sealing valve  40  removably couples the removable filter cartridge  10  to the filter head  90 . As shown in  FIG.  1   , the filter housing  20  is removably coupled to the filter head  90  by the sealing valve  40 . 
       FIG.  2    is an exploded view of the removable filter cartridge  10 .  FIG.  2    shows the filter housing  20 , sealing valve  40 , and filter head  90  when uncoupled from each other. In the illustrated embodiment, the sealing valve  40  is uncoupled from the filter head  90  by being unscrewed from the filter head  90 , and the filter housing  20  is uncoupled from the sealing valve  40  by being unscrewed from the filter head  90 . 
       FIG.  3    is a top view of the filter assembly  1 . The sealing valve  40  has an open position and a closed position. For example, the sealing valve  40  is configured to be moved between its open position and closed person by hand.  FIG.  4 A  is a vertical cross-sectional view of sealing valve  40  in the open position.  FIG.  4 B  is a vertical cross-sectional view of sealing valve  40  in the closed position. For example, the vertical cross-sectional view in  FIGS.  4 A and  4 B  is along the cross-section indicated by the line IV-IV in  FIG.  3   . The sealing valve  40  includes a valve body  42  and a valve plate  70  that is slidable in the valve body  42 . The sealing valve  40  has an open position and a closed position. In the open position, the sealing valve  40  is configured to allow fluid to flow through the sealing valve  40 . In the closed position, the sealing valve  40  is configured to block flow through the sealing valve  40 . 
     The sealing valve  40  has a first end  46  and a second end  48  opposite to the first end  46 . For example, the valve body  42  includes the first end  46  and the second end  48  of the sealing valve  40 . The valve body  42  includes an opening  50  that extends through a side  52  of the valve body  42 . The side  52  extends between the first end  46  and the second end  48  of the sealing valve  40 . The valve plate  70  extends into and through the opening  50  in the side of the valve body  42 . 
     The sealing valve  40  is configured to be actuated between the open position and the closed position by sliding the valve plate  70 . In particular, the valve plate  70  is actuated between the open position and the closed position by sliding the valve plate  70  within the valve body  42 . The valve plate  70  moves between the closed position and the open position by being slid relative to the valve body  42 . For example, the valve plate  70  is changed between the closed position and the open position by moving the position of the valve plate  70  within the valve body  42  (e.g., changing the position of the valve plate  70  in the opening  50  of the valve body  42 ). The valve body  42  has a substantially cylindrical shape with an axis A. The axis A being the vertical axis of the cylindrical shape. The valve plate  70  is actuated between the closed position and the open position by moving the valve plate  70  in along a direction (e.g., along direction D 2 ) perpendicular to the axis A. For example, actuated from closed to open by moving in direction D 2  and from open to closed by moving in an opposite direction D 3 . 
     In the illustrated embodiment, the valve plate  70  is moved from the open position ( FIG.  4 A ) to the closed position ( FIG.  4 B ) by the valve plate  70  being pulled away from the valve body  42 , and is moved from the closed position to the open position by pushing the handle  54  closer to the valve body  42 . For example, the length of the valve plate  70  disposed in the valve body  42  is changed to change valve plate  70  between its open and closed positions. 
     The sealing valve  40  includes a handle  54  affixed to the valve plate  70 . The handle  54  is used to slide the valve plate  70  between the open position ( FIG.  4 A ) and the closed position ( FIG.  4 B ). A human operator (e.g., technician, etc.) can push and pull the handle  54  to move the sealing valve  40  between its open and closed positions. The handle  54  is a first one of pushed or pulled to move the valve plate  70  from its open position to its closed position and is the other one of pushed or pulled to move the valve plate  70  from its closed position to its open position. In the illustrated embodiment, the handle  54  is pushed towards the valve body  42  (e.g., moved closer to the valve body  42 ) to move the valve plate  70  from its closed position to its open positioned and is pulled away from the valve body  42  (e.g., moved farther away from the valve body  42 ) to move the valve plate  70  from its open position back to its closed position. 
       FIG.  5    is an exploded perspective view of the valve plate  70 . As shown in  FIG.  5   , the valve plate  70  has a planar shape. The valve plate  70  has a first side  72  (e.g., a top side) and a second side  74  (e.g., a bottom side). The second side  74  is generally obscured in  FIG.  5    (e.g., second side  74  is shown in  FIG.  6   ). The valve plate  70  includes through holes  76  and configured to allow fluid to flow through the valve plate  70  when in the open position. Each of the through holes  76  separately extends through the valve plate  70  from the first side  72  to the second side  74 . The through holes  76  in the valve plate  70  include at least one inlet through hole  76 A,  76 C and at least one outlet through hole  76 B. In the illustrated embodiment, the valve plate  70  includes two inlet through holes  76 A,  76 C and one outlet through hole  76 B. The valve plate  70  including a first through hole  76 A that is an inlet through hole, a second through hole  76 B that is an outlet through hole, and a third through hole  76 C that is another inlet through hole. It should be appreciated that the valve plate  70  in other embodiments may have a different number inlet and/or outlet through holes  76 A,  76 B,  76 C (e.g., one inlet through hole, two outlet through holes, etc.) based on the configuration the filter housing  20  and the filter head  90 . 
     As shown in  FIG.  5   , the valve plate  70  can include a respective pair of seals  78 ,  80  for each through hole  76 . The seals  78 ,  80  include first seals  78  provided on the first side  72  of the valve plate  70  and second seals  80  provided on the second side  74  of the valve plate  70 . Each seal  78 ,  80  surrounds its respective through hole  76  on its respective side  72 ,  74 . The seals  78 ,  80  for the through holes  76  are configured to provide sealing between the valve plate  70  and the valve body  40  when in the open position (e.g., see  FIGS.  4 A and  6   ). The first seals  78  provide sealing between the valve plate  70  and the valve body  42  along the top side  72  of the valve plate  70  in the open position, and second seals  80  provide sealing between the valve plate  70  and the valve body  42  along the bottom side  74  of the valve plate  70  in the open position. 
     In the illustrated embodiment, the valve plate  70  includes a respective first seal  78  on the first side  72  and a respective second seal  80  on the second side  74  for each through hole  76  (e.g., shown  FIGS.  6  and  7   ). For example, the valve plate  70  includes a first pair of first and second seals  78 A,  80 A for a first through hole  76 A, a second pair of first and second seals  78 B,  80 B for a second through hole  76 B, and a third pair of first and second seals  78 C,  80 C for a third through hole  76 C. 
     The valve plate  70  includes portions  82  configured to block fluid flow through the valve plate  70  when the valve plate  70  is in the closed position (shown in  FIG.  4 B ). The portions  82  are solid portions of the valve plate  70  and may be referred to as blocking portions. The valve plate  70  can include a corresponding blocking portion  82  for each through hole  7  in the valve plate  70 . As shown in  FIG.  5   , the valve plate  70  can include a first blocking portion  82 A that corresponds to the first through hole  72 A, a second blocking portion  82 B that correspond to the second through hole  72 B, and a third blocking portion  82 C that corresponds to the third through hole  72 C. 
     As shown in  FIG.  5   , the valve plate  70  can include a respective pair of seals  79 ,  81  on the valve plate  70  for each blocking portion  82  in a similar manner to the seals  78 ,  80  for the through holes  76 . The seals  79 ,  81  for the blocking portions  82  are configured to provide sealing between the valve body  40  and the valve plate  70  when in the closed position. First seals  79  for the blocking portions  82  provide sealing between the valve plate  70  and the valve body  42  along the top side  72  of the valve plate  70  in the closed position, and the second seals  81  for the blocking portions  82  provide sealing between the valve plate  70  and the valve body  42  along the bottom side  74  of the valve plate  70  in the closed position. 
     For example, for each blocking portion  82 , a first seal  79  surrounds its respective blocking portion  82  on the first side  72  of the valve plate  70  and a second seal  81  surrounds its respective blocking portion  82  on the second side  74  of the valve plate  70 . In another embodiment, the valve plate  70  may include a different number of blocking portions  82  (e.g., two blocking portions, etc.) as similarly discussed above for the through holes  72 . 
     The seals  78 ,  79 ,  80 ,  81  can be made of an elastomer different from the polymer of the valve body  42  and/or the valve plate  70  and are embedded in their respective side  78 ,  79 ,  80 ,  81  of the valve plate  70  (e.g., press fit into a respective groove in the valve plate  70 ). Examples of the polymer for the valve plate  70  and/or valve body  42  may include, but are not limited to, PFA, PTFE, modified PTFE, PP, and PE. For example,  FIGS.  4 A and  4 B  show the seals  78 ,  79 ,  80 ,  81  embedded in the assembled valve plate  70 . In other embodiments, the seals  78 ,  79 ,  80 ,  81  may each be an integral ridge formed in the valve plate  70 . 
       FIG.  6    is a vertical cross-sectional view of the filter assembly  1 . For example, the vertical cross-section of  FIG.  6    can be along the line VI-VI in  FIG.  3   . For illustrative purposes, the filter head  90  in  FIG.  6    is rotated relative to the removable filter cartridge  10  (e.g., rotated  90  degrees clockwise) from its position as shown in  FIG.  1   .  FIG.  6    shows the sealing valve  40  in the open position (e.g., as shown in  FIG.  4 A ) that allows the fluid f to pass through the filter assembly  1 . 
     The filter housing  20  includes an internal volume  22  that contains a filter  24 . Dashed lines are provided in  FIG.  6    to illustrate the flow of the fluid f through the filter assembly  1  In the open position, fluid f from the filter head  90  is allowed to pass through the sealing valve  40  to the filter housing  20 , pass through the filter housing  20 , and then pass from the filter housing  40  through the sealing valve  40  back to the filter head  90 . The open position of the sealing valve  40  is configured to allow the fluid to flow into and out of the internal volume  22  of the filter housing  20 . The filter  24  filters fluid f as it passes through the removable filter cartridge  10 . The fluid f is filtered as it passes through the filter housing  40 , such that the fluid f flowing back to the filter head  20  (and then out through the fluid outlet  4 ) is filtered fluid. 
     As shown in the illustrated embodiment, the filter housing  20  may have a bowl shape. The filter housing  20  has an open end  26  and a closed end  28 . The open end  26  and the closed end  28  of the filter housing  20  are opposite ends of the length L of the filter housing  20 . The open end  26  may also be referred to as a fluid inlet-outlet as the fluid f enters and exits the filter housing  20  through its open end  26 . As shown in  FIG.  6   , the first end  46  of the sealing valve  40  is configured to be coupled to the filter housing  20 . The first end  46  of the sealing valve  46  is coupled to the open end  26  of the filter housing  20 . 
     In the illustrated embodiment, the first end  46  of the sealing valve  40  is coupled to the filter housing  20  by threads on the sealing valve  40  and the filter housing  20 . For example, the filter housing  20  is configured to be screwed onto the sealing valve  40  by screwing a coupling nut  30  of the filter housing  20  onto the sealing valve  40 . In an embodiment, the threads of the sealing valve  40  (e.g., threads of the coupling nut  56  of the sealing valve  40 ) and the threads of the filter housing  20  (e.g., threads of the coupling nut  30 ) have the same structure (e.g., thread size, thread spacing, etc.). It should be appreciated that sealing valve  40  in other embodiments may be coupled to the filter housing  20  in a different manner than being screwed together via threads. In another embodiment, the sealing valve  40  and the filter housing  20  may be coupled by, for example but not limited to, clamping (e.g., with a tri-coupler, etc.) or bonding (e.g., thermal bonding of the sealing valve  40  to the filter housing  20 , etc.). 
     The sealing valve  40  is configured to be removably coupled to the filter head  90 . The second end  48  of the sealing valve  40  is removably coupled to the filter head  90 . In the illustrated embodiment, the sealing valve  40  includes threads that screw into threads on the filter head  90  to removably couple the removable filter cartridge  10  to the filter head  90 . As shown in  FIG.  6   , the sealing valve  40  can include a coupling nut  56  with threads that screw onto to the threads of the filter head  90 . It should be appreciated that the sealing valve  40  in other embodiments may configured to removably couple to the filter head  90  in a different manner than via threads. In an embodiment, the sealing valve  40  may be configured to removably couple to the filter head  90  by, for example but not limited to, a coupler (e.g., a tri-coupler, or the like). 
     As shown in  FIG.  6   , the sealing valve  40  can include a circumferential groove  58  and a snap ring  60  disposed in the circumferential groove  58  of the valve body  42 . The circumferential groove  58  extends around a circumference of the sealing valve  40 . The snap ring  60  is configured to be compressed between the sealing valve  40  and the filter head  90  when the sealing valve  40  is removably coupled to the filter head  90 . In the illustrated embodiment, the snap ring  60  is compressed between the coupling nut  56  of the sealing valve  40  and the filter head  90  when the coupling nut  56  is screwed onto the filter head  90 . 
     The filter housing  20  includes a first inlet  34 A, a second inlet  34 B, and an outlet  36  provided at the open end  26  of the filter housing  20 . For example, the first inlet  34 A, the second inlet  34 B, and the outlet  36  are different passages extending into the filter housing  20  from the open end  26 . In the illustrated embodiment, the outlet  36  is disposed radially between the first inlet  34 A and the second inlet  34 B. The filter housing  20  is configured such that the fluid f enters the filter housing  20  through the inlets  34 A,  34 B and exits the filter housing  20  (e.g., after passing through and being filtered by the filter  24 ) through the outlet  36 . It should be appreciated that the filter housing  20  in an embodiment may have a different number of inlets and/or outlets than  3 . In some embodiments, the filter housing  20  may include one or more inlets  34 A,  34 B and one or more outlets  36 . In an embodiment, the filter housing  20  may include one inlet  34 A and one outlet  34 A. In another embodiment, the filter housing  20  may include two or more inlets  34 A,  34 B and/or two or more outlets  36 . 
     The valve body  42  includes passages  62  for the inlets and outlet(s)  34 A,  34 B,  36  in the open end  26  of the filter housing  20 . Each of the passages  62  extends through the valve body  42 . As shown in  FIG.  6   , the passages  62  in the valve body  42  include a first passage  62 A, a second passage  62 C, and a third passage  62 B that each separately extend through the valve body  42 . Each of the passages  62  extends through the valve body  42  from the first end  46  to the second end  48 . 
     The passages  62  in the valve body  42  include at least one inlet passage  62 A,  62 C and at least outlet passage  62 B. The inlet passages  62 A,  62 C each connect the fluid inlet  2  of the filter head  90  (e.g., the passage in the filter head  90  extending from the fluid inlet  2 ) to the inlet(s)  34 A,  34 B of the filter housing  20 . The outlet passage  62 B connects the outlet  36  of the filter housing  20  (e.g., the passage in the filter head  90  extending from the fluid outlet  4 ) to the fluid outlet  4  of the filter head  90 . 
     As shown by the dashed lines in  FIG.  6   , the inlet passages  62 A,  62 C fluidly connect the fluid inlet  2  of the filter head  90  to the first and second inlets  34 A,  34 B of the filter housing  20 , and the outlet passage  62 C fluidly connects the outlet  36  of the filter housing  20  to the fluid outlet  4  of the filter head  90 . For example, the first and third passages  62 A,  62 C direct the fluid f supplied from the passage of the fluid inlet  2  of the filter head  90  to the inlets  34 A,  34 B of the filter housing  20 . For example, the second passage  62 B directs the filtered fluid f from the outlet  36  to the passage in the filter head  90  for the fluid outlet  4 . 
     The sealing valve  40  is configured such that when in its open position (e.g., as shown in  FIGS.  4 A and  6   ), the valve plate  70  is disposed in the valve body  42  such the through holes  76  in the valve plate  70  are aligned with the passages  68 . A through hole  76  is “aligned” as the through hole  76  is disposed in its respective passage  62 A,  62 B,  62 C. When aligned with its respective passage  68 , fluid can flow through said passage  68  by passing through said through hole  76 . As shown in  FIG.  6   , when the in the open position, the first through hole  76 A in the valve plate  70  is aligned with the first passage  62 A, the second through hole  76 B in the valve plate  70  aligns with the second passage  62 B, and the third through hole  76 C aligns with the second passage  62 C. 
     It should be appreciated that the filter housing  20  in other embodiments may have a different number of inlets and outlets  34 A,  34 B,  36  at its open end  26  than three (e.g., one inlet, more than two inlets, multiple outlets etc.). In such embodiments, the sealing valve  40  may have a different number of passages  62 A,  62 B,  62 C than three (e.g., same number of corresponding passages as inlets and outlets in the filter housing  20 , two of the passages, etc.). 
       FIG.  7    is a vertical cross-sectional view of the filter assembly  1  with the sealing valve  40  in the closed position (e.g., as shown in  FIG.  4 B ).  FIG.  7    is similar view to  FIG.  6    except that the sealing valve  40  is moved to its closed position. The sealing valve  40  in the closed position is configured to block fluid f from flowing through the filter assembly  1 . As shown in  FIG.  7   , the seal valve  40  in its closed position blocks the fluid from passing through the seal valve  40  between filter housing  20  and the filter heat  90  (e.g., blocks fluid from the filter head  90  to the filter housing  20  and blocks fluid flow from the filter housing  20  to the filter head  90 ). The removable filter cartridge  10  is configured to have the seal valve  40  actuated to the closed position while still removably coupled to the filter head  90 . When the valve seal  40  is changed to its closed position (e.g., the valve plate  70  is slide/moved to the closed position), the valve seal  40  in the closed position seals the internal volume  22  of the filter housing  20 . The closed valve seal  40  blocks flow of fluid into and out of the open end  26  of the filter housing  20  and seals the open end  26  of the filter housing  20 . 
     The valve plate  70  blocks each of the passages  62  in the closed position. The sliding of the valve plate  70  into the closed position causes the through holes  76  in the valve plate  70  to no longer be aligned with their respective passage  62 . The sliding of the valve plate  70  into the closed position moves the blocking portions  82  of the valve plate  70  to be disposed in the passages  62 . Each of the passages  62  are blocked by the blocking portions  82  of the valve plate  70 . For example, each blocking portions  82  extends across a corresponding one of the across the passages  62 . As shown in  FIG.  7   , the first blocking portion  82 A of the valve plate  70  extends across and blocks the first passage  62 A, the second blocking portion  82 B of the valve plate  70  extends across and blocks the second passage  62 B, and the third blocking portion  82 C of the plate  70  extends across and blocks the third passage  62 C. 
     When the removable filter cartridge  10  is uncoupled from the filter head  90  (e.g., the coupled filter housing  20  and sealing valve  40  are uncoupled/unscrewed from the filter head  90 ), the sealing valve  40  is configured to maintain the sealing of the internal volume  22 . The sealing valve  40  is configured to maintain the sealing of filter housing  20  while the cartridge remains uncoupled from a filter head. In particular, the closing of the sealing valve  40  seals the filter housing  20  such that any of the liquid in the internal volume  22  is trapped within the removable filter cartridge  10 . This is advantageous over previous configuration in that the removable filter cartridge  10  can be removed more quickly without having to be drained of liquid. 
       FIGS.  8  and  9    show another embodiment of a filter assembly  101 .  FIG.  8    is a side perspective view of the filter assembly  101 .  FIG.  9    is an exploded view of the filter assembly  101 . The filter assembly  101  includes a removable filter cartridge  110  that is coupled to a filter head  190  and includes a filter housing  120  and a sealing valve  140 . The filter assembly  101  generally has a similar configuration to the filter assembly  1  in  FIGS.  1 - 8    except for the sealing valve  140 . For example, the filter head  90  includes a fluid inlet  102  and a fluid outlet (obscured in  FIGS.  7  and  9   ) of the filter assembly  101  and is configured to supply the fluid through the removable filter cartridge  110 ; and the removable filter cartridge  110  filters the fluid passing that passes through similar to the removable filter cartridge  1  in  FIG.  1   . For example, the sealing valve  140  has a first end  146  coupled to the filter housing  120  and a second end  148  removably coupled to the filter head  90 . The filter assembly  101  can have features similar to the filter assembly  1  in  FIGS.  1 - 8    unless described otherwise. 
     The filter housing  120  and the filter head  190  have a similar configuration to the filter head  90  and filter housing  20  of the filter assembly  1  in  FIGS.  1 - 8   . It should be appreciated that the filter housing  120  and/or the filter head  190  may be different in other embodiments as similarly described for the filter housing  20  and the filter head  90  in  FIGS.  1 - 8   . 
       FIG.  10    is an exploded view of the sealing valve  140 . The sealing valve  140  has an open position and a closed position. In the open position, the sealing valve  140  is configured to allow fluid to flow through the sealing valve  140 . In the closed position, the sealing valve  140  is configured to block flow through the sealing valve  140 . The sealing valve  140  has a first end  146  and a second end  148  opposite to the first end  146 . For example, the valve body  142  includes the first end  146  and the second end  148  of the sealing valve  140 . 
     The sealing valve  140  is configured to be removably coupled to the filter head  190  as similarly discussed for the sealing valve  40  and filter head  90  in  FIGS.  1 - 8   . In the illustrated embodiment, the second end  148  of the sealing valve  140  is removably coupled to the filter head  190  via a coupling nut  156  of the sealing valve  140 . The sealing valve  140  can include the coupling nut  156  and a snap ring  160  (shown in  FIG.  10   ) for coupling the sealing valve  140  to the filter head  190 . For example, the threads of the coupling nut  156  are screwed into threads on the filter head  190 . In an embodiment, the sealing valve  140  may be configured to removably couple to the filter head  190  by, for example but not limited to, a coupler (e.g., a tri-coupler, or the like). 
     The sealing valve  140  includes a valve body  142  and a valve gate  170 . The valve gate  170  is disposed within the valve body  142  and is rotatable within the valve body  142 . The sealing valve  140  is configured to be actuated between the open position and the closed position by rotating the valve gate  170 . In particular, the sealing valve  140  is actuated between the open position and the closed position by rotating the valve gate  170  within the valve body  142 . The valve gate  170  moves between the closed position and the open position by being rotated relative to the valve body  142 . 
     For example, the sealing valve is changed between the closed position and the open position by rotating the valve gate  170  within the valve body  142 . 
     In the illustrated embodiment, the valve gate  170  is actuated between open and closed by being rotated by  90  degrees. For example, the valve gate  170  is moved from the open position to the closed position by the valve gate  170  being rotated by  90  degrees relative to the valve body  42 , and is moved from the closed position to the open position by rotating the valve gate  170  either 90 degrees further (e.g., 180 degrees from its starting closed position) or 90 degrees in the opposite direction (e.g., returning the valve gate  170  to its starting closed position. In an embodiment, the valve gate  170  may be configured to be rotated by at least  45  degrees to move between the open and closed positions. The valve gate  170  is configured to be rotated by the filter housing  120  as discussed below. The filter housing  120  configured to be rotated by hand to actuate the sealing valve  140  by hand between the open and closed positions. 
     In the illustrated embodiment, the valve gate  170  includes a first side  172  (e.g., a top side) and a second side  174  (e.g., a bottom side) opposite to the first side  172 . The second side  174  is generally obscured in  FIG.  10    (e.g., second side  174  is shown in  FIG.  11   ). The valve gate  170  includes a valve plate  178  disposed at the second side  174  of the valve gate  170 . For example, the valve plate  178  provides the bottom surface of the valve gate  170 . In the illustrated embodiment, the valve gate  170  includes a valve cylinder  180  and the valve plate  178  is an affixed to the bottom of the valve cylinder  180  to form the valve gate  170 . In an embodiment, the valve plate  178  is made an elastomer. In another embodiment, the valve plate  178  and valve cylinder  180  may be formed as a single integral piece. 
     The valve plate  178  includes through holes  176  that extend through the valve plate  178 . As shown in  FIG.  10   , the through holes  176  are provided along the same vertical plane. The through holes  176  are spaced apart from each other in the valve plate  178 . The through holes  176  include inlet through holes  176 A and outlet through holes  176 B. The valve plate  178  also includes blocking portions  182  configured to block fluid flow through the valve gate  170  when the valve gate  170  is in the closed position (shown in  FIG.  12   ). The portions  182  are solid portions of the valve gate  170  and may be referred to as blocking portions. The valve gate  170  includes a corresponding blocking portion  182  for each through hole  176  in the valve plate  170 . The through holes  176  and blocking portions  182  are discussed in more detail below. 
     The bottom  174  of the valve gate  170  may include a seal around each of the through-holes  176  and/or blocking portions  182  similar to the valve plate  70  in  FIG.  5   . The seals may be embedded into the bottom of the valve gate  170  or integral to the valve gate  170 . For example, the seals may be integral to the valve plate  178  (e.g., as shown in  FIGS.  11  and  12   ) 
     In the illustrated embodiment, the valve gate  170  includes a key slot  184  for rotatably connecting the valve gate  170  to the filter housing  120 . The key slot  184  is used to rotatably connect the valve gate  170  and the filter housing  120  such that rotation applied to the filter housing  120  also rotates the gate valve  170  within the valve body  142  (e.g., the gate valve  170  rotates with any rotation of the filter housing  120 ). The rotatable connection of the valve gate  170  and the filter housing  120  is discussed in more detail below. 
       FIG.  11    is a vertical cross-sectional view of the filter assembly  101 . For example, the vertical cross-section of  FIG.  11    is along a similar vertical plane to  FIGS.  7  and  8   .  FIG.  11    shows the sealing valve  140  in the open position that allows the fluid f to pass through the filter assembly  101 . 
     The filter housing  120  generally has the same configuration as the filter housing  120  of the filter assembly  1  in  FIG.  7   . When the sealing valve  140  is open, the fluid flows from the inlets  134 A through the filter  124  disposed in the internal volume  122  of the filter housing  120 , then the filtered fluid flows out of the filter housing  120  through the outlet  136 . For example, the filter housing  120  includes the first inlet  134 A, the second inlet  134 B, and the outlet  136  provided at the open end  126  of the filter housing  120 . In an embodiment, the filter housing  120  may be modified in a similar manner as discussed for the filter housing  20 . For example, in some embodiments, the filter housing  20  may include one or more inlets  34 A,  34 B and one or more outlets  36 . 
     The valve body  142  includes passages  162  for the inlets and outlet(s)  134 A,  134 B,  136  in the open end  126  of the filter housing  120 . Each of the passages  162  extends through the valve body  142 . In the open position, the passages  162  also each extend through the valve gate  170  as shown in  FIG.  11   . As shown in  FIG.  11   , the passages  162  in the valve body include a pair of inlet passages  162 A and a pair of outlet passages  162 B. Each of the passages  162  has an opening  163  disposed in the second end  148  of the sealing valve  140 . For example, the inlet passages  162 A each include a respective inlet opening  163 A and the outlet passages  162 B each include a respective outlet opening  163 B. Fluid enters the inlet passages  162 A (e.g., enters the sealing valve  140  from the valve head  190 ) through the inlet openings  163 A and the filtered fluid exits the outlet passages  162 B (e.g., exits the sealing valve  140  into the valve head  190 ) through the outlet openings  163 A. It should be appreciated that there may be a different number of openings  163  in other embodiments. For example, the number of openings  163  can correspond with the number of passages  162  provided in a particular embodiment of the sealing valve  140 . 
     As shown in  FIG.  11   , the passages  162  in the valve body  42  includes two inlet passages  162 A and two outlet passages  162 B that each separately extend through the bottom end  148  of the valve body  42 . The passages  162  in the valve body  142  include at least one inlet passage  162 A and at least outlet passage  162 B. In the open position, the inlet passages  162 A each connect the fluid inlet  102  of the filter head  190  (e.g., the passage in the filter head  90  extending from the fluid inlet  2 ) to the inlet(s)  134 A,  134 B of the filter housing  120 . The outlet passages  162 B connect the outlet  136  of the filter housing  20  to the fluid outlet  104  of the filter head  90  (e.g., the passage in the filter head  90  extending from the fluid outlet  104 ). 
     As shown by the dashed lines in  FIG.  11   , the inlet passages  162 B fluidly connect the fluid inlet  102  of the filter head  190  to the first and second inlets  134 A,  134 B of the filter housing  20 , and the outlet passages  162 B fluidly connect the outlet  136  of the filter housing  120  to the fluid outlet  104  of the filter head  190 . For example, the first and second inlet passages  162 A direct the fluid f supplied from the passage of the fluid inlet  102  of the filter head  190  to the inlets  134 A of the filter housing  120 . For example, the first and second outlet passages  162  direct the filtered fluid f from the outlet  136  to the passage in the filter head  190  for the fluid outlet  104 . 
     The sealing valve  140  is configured such that when in its open position (e.g., as shown in  FIG.  11   ), the valve gate  170  is rotationally disposed in the valve body  142  such the through holes  176  in the valve gate  170  are aligned with the passages  168 . In particular, in the valve gate  170  in the open position is rotated to a position in which its each of its through holes  176  are aligned with a respective one of the openings  163  of the passages  162 . A through hole  176  is “aligned” when the through hole  176  is disposed in its respective passage  162 . For example, when open, each through hole  176  in the valve plate  178  of the valve gate  170  is aligned with a respective one of the openings  163  in the valve body  142  of its respective passage  162 . A through hole  167  and its respective opening  163  align by overlapping in the axial direction (e.g., direction D 1 ) of the sealing valve  1 . This alignment allows for the working fluid to flow between the through hole  167  and its respective opening  163 . 
     When aligned with its respective passage  168 , fluid can flow through said passage  168  by passing through said through hole  176 . As shown in  FIG.  11   , when the in the open position, a first inlet through hole  176 A in the valve plate  178  is aligned with a first inlet passages  162 A, the second inlet through hole  176 A in the valve plate  178  aligns with a second inlet passage  162 A, a first outlet through hole  176 B aligns with a first outlet passage  162 B, and a second outlet through  162 B aligns with a second outlet passage  162 B. 
     It should be appreciated that the filter housing  120  in other embodiments may have a different number of inlets and outlets  134 A,  134 B,  136  at its open end  126  than four (e.g., one inlet, more than two inlets, one outlet, more than two outlets, etc.). In such embodiments, the sealing valve  140  may have a different number of passages  162 A,  162 B than four (e.g., same number of corresponding passages as inlets and outlets in the filter housing  120 , two of the passages, etc.). 
       FIG.  12    is a vertical cross-sectional view of the filter assembly  101  with the sealing valve  140  in the closed position. The filter housing  120  is rotationally connected to the valve gate  170  of the filter housing  120 .  FIG.  12    is similar view to  FIG.  11    except that the sealing valve  140  is moved to its closed position. The sealing valve  140  is moved from its open position to its closed position by rotating the valve gate  170  within the valve body  142 . 
     In the illustrated embodiment, the housing  120  has a projection  129  that is disposed in a key slot  184  of the valve gate  170 . The projection  129  rotationally connecting the valve gate  170  and filter housing  120  such that rotation of the filter housing  120  rotates the valve gate  170 . The filter housing  120  and the valve gate  170  configured to always rotate together in the assembled filter cartridge  110 . The sealing valve  140  configured to be actuated between its open position (e.g., shown in  FIG.  11   ) and its closed position (e.g., shown in  FIG.  12   ) by rotating the filter housing  120 . 
     In the illustrated embodiment, the coupling nut  130  couples the filter housing  120  to the sealing valve  140 . The sealing valve  140  is moved from the open position to the closed position by partially unscrewing the coupling nut  130  (e.g., partially uncoupling the filter housing  120  and the sealing valve  140 ), rotating the filter housing  120 , and then screwing the coupling nut  130  (e.g., re-fully coupling the filter housing  120  and the sealing valve  140 ). The coupling nut  130  is only unscrewed enough to allow the filter housing  120  to rotate relative to the valve body  142  of the sealing valve  140 . The coupling nut  130  remains sufficiently screwed onto the sealing valve  140  to maintain the seal between the filter housing  120  and the sealing valve  140 . 
     The sealing valve  140  in the closed position is configured to block fluid f from flowing through the filter assembly  101 . As shown in  FIG.  12   , the seal valve  140  in its closed position blocks the fluid from passing through the seal valve  140  between the filter housing  120  and the filter head  190  (e.g., blocks fluid flow from the filter head  190  to the filter housing  20  and blocks fluid flow from the filter housing  120  to the filter head  190 ). The removable filter cartridge  110  is configured to have the seal valve  140  actuated to the closed position while still removably coupled to the filter head  190 . When the valve seal  140  is changed to its closed position (e.g., the valve gate  170  is rotated/moved to the closed position), the valve seal  140  in the closed position seals the internal volume  122  of the filter housing  120 . The closed valve seal  140  blocks flow of fluid into and out of the open end  126  of the filter housing  120  and seals the open end  126  of the filter housing  120 . 
     The valve gate  170  blocks each of the passages  162  in the closed position. In particular, the valve gate  170  in the closed position blocks the openings  163  of the passages  162  in the valve body  142 . The rotating of the valve gate  170  into the closed position causes the through holes  176  in the valve gate  170  to no longer be aligned with their respective passage  162 . For example, the through holes  176  are each in rotated position relative to the opening  163  of their respective passageway  162 . The rotation of the valve gate  170  into the closed position moves the blocking portions  182  of the valve gate  170  to be disposed in the passages  162 . In particular, the rotation of the valve gate  170  moves the blocking portions  182  of the valve gate  170  to be disposed over the openings  163 . The block portions  182  disposed over the openings  163  along the inside of the valve body  142 . 
     Each of the passages  162  is blocked by a blocking portions  82  of the valve gate  170 . For example, each blocking portions  182  extends across a corresponding one of the across the passages  162 . As shown in  FIG.  12   , a first blocking portion  182  of the valve gate  170  extends across and blocks the first inlet passage  162 A, a second blocking portion  182  of the valve plate  70  extends across and blocks the second inlet passage  162 A, a third blocking portion  182  of the valve gate  170  extends across and blocks the first outlet passage  162 B, and a fourth blocking portion  182  of the valve gate  170  extends across and blocks the second outlet passage  162 B. 
     When the removable filter cartridge  110  is uncoupled from the filter head  180  (e.g., the coupled filter housing  120  and sealing valve  140  are uncoupled/unscrewed from the filter head  90 ), the sealing valve  140  is configured to maintain the sealing of the internal volume  122 . The sealing valve  140  is configured to maintain the sealing of filter housing  120  while the cartridge remains uncoupled from a filter head. In particular, the closing of the sealing valve  140  seals the filter housing  120  such that any of the liquid in the internal volume  122  is trapped within the removable filter cartridge  110 . This is advantageous over previous configuration in that the removable filter cartridge  110  can be removed more quickly without having to be drained of liquid. 
       FIG.  13    shows a block flow diagram of a method  1000  of retrofitting a filter housing (e.g., filter housing  20  in  FIG.  2   , filter housing  120  in  FIG.  8   ). The filter housing has an internal volume (e.g., internal volume  22 , internal volume  122 ) containing a filter (e.g., filter  24 , filter  124 ). For example, the method  1000  may be for retrofitting a filter housing (e.g., filter housing  120 ) that was originally intended to be directly removably coupled to a filter head (e.g., filter header  90 , filter head  180 ). The method starts at  1010 . 
     At  1010 , the filter housing is uncoupled from a filter head. Removing the filter housing from the filter head  1010  includes uncoupling an open end of the filter housing (e.g., open end  26 , open end  126 ) from the filter head. In an embodiment, uncoupling the filter housing from the filter head at  1010  may include unscrewing the filter housing form the filter head  1012 . For example, unscrewing the filter housing from the filter head can include unscrewing a coupling nut of the filter housing (e.g., coupling nut  30 , coupling nut  130 ) from the filter head. The method  1000  then proceeds to  1020 . 
     At  1020 , a first end (e.g., first end  46 , first end  146 ) of a sealing valve (e.g., sealing valve  40 , sealing valve  140 ) is coupled to the removable filter to form a removable filter cartridge (e.g., removable filter cartridge  10 , removable filter cartridge  110 ). In an embodiment, coupling the sealing valve to the removable filter  1020  includes screwing together the filter housing and the sealing valve  1022 . For example, screwing together the filter housing and the sealing valve  1022  can include screwing the coupling nut of the filter housing onto the sealing valve. The method  1000  then proceeds to  1030 . 
     At  1030 , the removable filter cartridge is removably coupled to the filter head. Removably coupling the cartridge to the filter head  1030  includes removably coupling a second end of the sealing valve (e.g., second end  48 , second end  148 ) to the filter head. In an embodiment, removably coupling the removable filter cartridge to the filter head at  1030  may include screwing the removable filter cartridge onto the filter head  1032 . For example, screwing the removable filter cartridge onto the filter head at  1032  may include screwing a coupling nut of the sealing valve (e.g., coupling nut  56 , coupling nut  156 ) onto the filter head. 
     It should be appreciated that the method  1000  in an embodiment may be modified to include features as described above with respect to the filter assembly  1  in  FIGS.  1 - 7    and/or the filter assembly  101  in  FIGS.  8 - 12   . 
     Aspects 
     Any of Aspects 1-12 can be combined with any of Aspects 13-18, and any of Aspects 13-15 can be combined with any of Aspects 16-18. 
     Aspect 1. A removable filter cartridge, comprising: a filter housing with an internal volume containing a filter configured to filter a liquid; and a sealing valve including a first end coupled to an open end of the filter housing and a second end configured to removably couple the removable filter cartridge to a filter head, the sealing valve configured to be actuated between an open position and a closed position by one of sliding the sealing valve and rotating the filter housing, wherein the open position allows liquid flow into and out of the internal volume of the filter housing, and the closed position seals the internal volume of the filter housing, the sealing valve configured to be actuated from the open position to the closed position while the sealing valve is removably coupled to the filter head and maintain the seal while the removable filter cartridge remains uncoupled. 
     Aspect 2. The removable filter cartridge of Aspect 1, wherein the sealing valve is configured to be actuated by hand between the open position and the closed position. 
     Aspect 3. The removable filter cartridge of any one of Aspects 1 and 2, wherein the sealing valve includes a valve body, a valve plate, and an inlet passageway and an outlet passageway extending through the valve body and configured to direct the liquid into and from the filter housing, the valve plate in the closed position blocking the inlet passageway and the outlet passageway. 
     Aspect 4. The removable filter cartridge of Aspect 3, wherein the valve plate includes a first through hole and a second through hole, in the open position, the first through hole is aligned with the inlet passageway allowing the liquid to flow through the inlet passageway and the second through hole is aligned with the outlet passageway allowing liquid to flow through the outlet passageway, and in the closed position, a first portion of the valve plate blocks the inlet passageway and a second portion of the valve plate blocks the outlet passageway. 
     Aspect 5. The removable filter cartridge of Aspect 4, wherein the valve plate includes: a first side and a second side opposite to the first side, the first through hole extending through the valve body from the first side to the second side, a first seal on the first side of the valve plate surrounding the first through hole, the first seal configured to provide sealing between the valve plate and the valve body in the open position, and a second seal on the first side of the valve plate surrounding the first portion of the valve plate, the second seal configured to provide sealing between the valve plate and the valve body in the closed position. 
     Aspect 6. The removable filter cartridge of Aspect 5, wherein the valve plate includes: a third seal on the second side of the valve plate surrounding the first through hole, the first seal and the second seal configured to provide sealing between the valve plate and the valve body in the open position, and a fourth seal on the second side of the valve plate surrounding the first portion of the valve plate, the third seal and the fourth seal configured to provide sealing between the valve plate and the valve body in the closed position. 
     Aspect 7. The removable filter cartridge of any one of Aspects 1-4, wherein the sealing valve is configured to be actuated between the open position and the closed position by sliding the sealing valve, the sealing valve including a valve body coupled to the filter housing and a valve plate slidable in the valve body to actuate the sealing valve between the open position and the closed position. 
     Aspect 8. The removable filter cartridge of Aspect 7, wherein the sealing valve includes a handle affixed to the valve plate, the valve seal configured to be actuated between the open position and the closed position by pushing the handle towards the valve body and pulling the handle away from the valve body. 
     Aspect 9. The removable filter cartridge of claim 7, wherein the valve body has a substantially cylindrical shape with an axis, the valve plate has a substantially planar shape, and the valve plate moves between the open position and the closed position by moving along a direction at or about perpendicular to the axis of the substantially cylindrical shape of the valve body. 
     Aspect 10. The removable filter cartridge of any one of Aspects 1-4, wherein the sealing valve is configured to be actuated between the open position and the closed position by rotating the filter housing, the sealing valve including a valve body and a valve plate disposed in the valve body, the valve plate rotatably coupled to the filter housing such that the valve plate rotates with the filter housing relative to the valve body. 
     Aspect 11. The removable filter cartridge of Aspect 10, wherein the sealing valve includes the valve body and the valve plate disposed in the valve body, the valve plate rotatably coupled to the filter housing, the valve plate configured to be rotatable within the valve body. 
     Aspect 12. The removable filter cartridge of any one of any one of Aspects 10 and 11, wherein the valve plate includes a first through hole and a second through hole, in the open position, the first through hole is aligned with an opening of the inlet passageway allowing the liquid to flow through the inlet passageway and a second through hole is aligned with an opening of the outlet passageway allowing liquid to flow through the outlet passageway, and in the closed position, a first portion of the valve plate blocks the inlet passageway and a second portion of the valve plate extends across and blocks the outlet passageway, the first through hole and the second through hole each being in a rotated position relative to the opening of the inlet passageway and the opening of the outlet passageway, respectively. 
     Aspect 13. A sealing valve for a removable filter cartridge, the sealing valve comprising: the first end configured to be removably coupled to a filter head; and the second end configured to be coupled to a filter housing to form the removable filter cartridge, the filter housing having an internal volume containing a filter, the sealing valve configured to be actuated between an open position and a closed position by one of sliding the sealing valve and rotating the filter housing, wherein the open position is configured to direct fluid from the filter head into the filter housing and then from the filter housing back to the filter head, and the closed position is configured to seal the internal volume of the filter housing, the sealing valve configured to be actuated from the open position to the closed position while the sealing valve is removably coupled to the filter head and maintain the seal while the removable filter cartridge remains uncoupled. 
     Aspect 14. The sealing valve of Aspect 15, wherein the sealing valve is configured to be actuated between the open position and the closed position by sliding the sealing valve, the sealing valve including a valve body coupled to the filter housing and a valve body slidable in the valve body to actuate the sealing valve between the open position and the closed position. 
     Aspect 15. The sealing valve of Aspect 13, wherein the sealing valve is configured to be actuated between the open position and the closed position by rotating the filter housing, the sealing valve including a valve body and a valve plate disposed in the valve body, the valve plate rotatably coupled to the filter body such that the valve plate rotates with the filter housing relative to the valve body. 
     Aspect 16. A method of retrofitting a filter housing, the filter housing having an internal volume containing a filter, the method comprising: removing the filter housing from a filter head, which includes uncoupling an open end of the filter housing from the filter head; coupling a first end of a sealing valve to the open end of the filter housing to form a removable filter cartridge; removably coupling the removable filter cartridge to the filter head, which includes removably coupling a second end of the sealing valve to the filter head , the sealing valve is configured to be actuated between an open position and a closed position, wherein the open position is configured to direct fluid from the filter head into the filter housing and then from the filter housing back to the filter head, and the closed position is configured to seal the internal volume of the filter housing, the sealing valve configured to be actuated from the open position to the closed position while the sealing valve is removably coupled to the filter head and maintain the seal while the removable filter cartridge remains uncoupled. 
     Aspect 17. The method of claim 16, wherein the seal member includes a valve plate slidable in a valve body, the method further comprising: actuating the sealing valve between the open position and the closed position, which includes sliding the valve plate into the valve body. 
     Aspect 18. The method of claim 16, wherein the seal member includes a valve gate disposed in a valve body, the valve gate rotatable coupled to the filter housing, the method further comprising: actuating the sealing valve between the open position and the closed position, which includes partially uncoupling the filter housing from the sealing valve and rotating the filter housing to rotate the valve gate relative to the valve body. 
     The examples disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.