Abstract:
A pressure decay testing system including a testing device for determining the reliability of connectors is provided and includes a pneumatic cylinder that raises and lowers a sealing member that closes a second end of a connector inserted in the device. A base member is adjacent pneumatic cylinder and includes a receiving surface having at least one receiving member for holding the connector. A channel is disposed therethrough though the receiving surface of the base member and aligns with an inner bore of the connector inserted in the testing device. An air line is attached to base member fluidly connecting inner bore of the connector with decay tester. Decay tester introduces a pressure differential through the channel to reach a predetermined set point pressure when the connector is closed by the testing device. Decay tester is configured to measure a change in pressure over time with respect to the predetermined set point.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/668,874 filed on Jul. 6, 2012, titled “PRESSURE DECAY TESTING SYSTEM FOR A CONNECTOR AND METHOD OF TESTING,” the disclosure of which is incorporated by reference as if fully rewritten herein. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to testing systems, and more particularly, to a pressure decay tester system and testing device for a connector and a method for evaluating the integrity of such connectors. 
     BACKGROUND OF THE INVENTION 
     Flexible containers are commonly used for containment and delivery of medical fluids. These containers are generally single use bags manufactured from one or more types of plastic film and include connectors for receiving or dispensing contents of the containers. The containers are often used in life science applications and in the manufacture of pharmaceuticals to contain liquid raw materials prior to or during manufacture; in other cases such containers may be used to contain the finished product. The contents of these containers may be precious, particularly when used in large scale production. It is not unusual for even small containers to contain material worth many thousands of dollars. 
     Accordingly, it is beneficial to try to determine in advance whether the connector for a container may have an abnormality or defect that might result in loss of material through the connector. 
     One common solution employed for testing connector integrity is to use a vacuum test. The vacuum test applies a vacuum to the connector to test whether the connector will provide an effective seal. A defective part is indicated by a vacuum drop on a dial indicator of the testing equipment. The vacuum test only identifies very large connector seal leaks or missing seals; it does not identify small leaks in a seal provided by the connector. Additionally, the vacuum test may not identify a faulty seal because the set-up of the vacuum test can allow the connector to close the leak which does not flag the faulty connector. 
     These and other disadvantages are found in known systems and methods for testing the integrity of seals for connectors. 
     SUMMARY OF THE INVENTION 
     According to an exemplary embodiment of the present disclosure, a testing device is provided. The testing device includes a platform, pneumatic cylinder, a base member and an air line. The pneumatic cylinder is mounted on a support with the support being connected to the platform. The pneumatic cylinder is operable to raise and lower within the testing device. The pneumatic cylinder includes a sealing member operable to close a second end of a connector when inserted in the testing device. The base member is situated on the platform and aligned with the pneumatic cylinder. The base member includes a receiving surface having at least one receiving member therein for holding the connector when inserted in the testing device. The base member includes a channel disposed therethrough the receiving surface. The channel aligns with an inner bore of the connector when inserted in the testing device. The air line is attached to the base member to fluidly connect the channel of the base member and the inner bore of the connector with a decay tester. 
     According to another exemplary embodiment of the present disclosure, a pressure decay testing system is provided. The pressure decay testing system includes a decay tester and a testing device in fluid communication with the decay tester. The testing device includes a platform, pneumatic cylinder, a base member and an air line. The pneumatic cylinder is mounted on a support with the support being connected to the platform. The pneumatic cylinder is operable to raise and lower within the testing device. The pneumatic cylinder includes a sealing member operable to close a second end of a connector when inserted in the testing device. The base member is situated on the platform and aligned with the pneumatic cylinder. The base member includes a receiving surface having at least one receiving member therein for holding the connector when inserted in the testing device. The base member includes a channel disposed therethrough the receiving surface. The channel aligns with an inner bore of the connector when inserted in the testing device. The air line is attached to the base member to fluidly connect the channel of the base member and the inner bore of the connector with the decay tester. The decay tester is configured to introduce a pressure differential through the air line into the channel and the inner bore of the connector to reach a predetermined set point pressure when the second end of the connector is closed by the sealing member of the pneumatic cylinder. The decay tester is configured to measure a change in pressure over time with respect to the predetermined set point. 
     According to another exemplary embodiment of the present disclosure, a method of testing a connector for pressure decay is provided by using the decay tester system. The method includes providing the above described decay tester system for testing a connector. The connector is inserted in the testing device with the first end of the connector being situated in the base member of the testing device. The pneumatic cylinder of the testing device is actuated, wherein the sealing member of the pneumatic cylinder seals the second end of the connector creating a sealed connection. A pressure differential is introduced into the channel and inner bore of the connector via the decay tester to achieve a predetermined set point pressure in the sealed connection. An initial pressure is measured at the predetermined set point pressure in the sealed connection. A second pressure is measured after a predetermined period of time has passed in the sealed connection. The initial pressure is compared to the second pressure to determine reliability of the connector. 
     One advantage of an embodiment of the present disclosure includes a pressure decay test that identifies defective connector seal assemblies before use. 
     Yet another advantage of an embodiment of the present disclosure is that the method identifies good connector seal assemblies from bad or defective connector seal assemblies with a high level of confidence. 
     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a pressure decay tester system in accordance with an exemplary embodiment. 
         FIG. 2  is a front view of the testing device in accordance an exemplary embodiment. 
         FIG. 3  is a perspective view of a pressure decay tester system in accordance with an exemplary embodiment. 
         FIG. 4  is a front partial section view of the testing device and connector in accordance with an exemplary embodiment. 
         FIG. 5  is a flow chart of a method of testing a connector for pressure decay. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Provided is a pressure decay tester system and testing device for an aseptic connector and a method for evaluating the integrity of connectors. 
       FIG. 1  is a perspective view of a pressure decay tester system  10  in accordance with an exemplary embodiment. The pressure decay tester system  10  includes a decay tester  30 . The decay tester  30  is any commercially available leak or flow tester, such as but not limited to, TME Solution™, available from TM Electronics, Inc. (Boylston, Mass.). The pressure decay tester system  10  also includes a testing device  40  in fluid communication with the decay tester  30  by at least one air line  22 . The testing device  40  seals a connector  66  to be tested. Typically, the connector  66  to be tested is an aseptic connector for use with the medical devices that can be sterilized after testing to ensure its aseptic nature. The connectors  66  commonly employ an o-ring or other gasket or seal to prevent leaking of the contents of a container with which the container is subsequently employed. 
     As shown in  FIGS. 1-4 , the testing device  40  includes a platform  60 , a pneumatic cylinder  50 , a base member  62  and an air line  22  to test connector  66 . The pneumatic cylinder  50  is mounted on a support  58  and the support  58  is connected to the platform  60  by a stand  54 . The support  58  may include a knob  56  for adjusting the support on the stand  54  to change the height of the pneumatic cylinder  50  relative to the base member  62 . The pneumatic cylinder  50  is operable to raise and lower within the testing device  40  and may be driven via lines  52  that are connected to a cylinder driver device  20 . The pneumatic cylinder  50  includes a sealing member  51  operable to close a second end  78  opposite a first end  76  of a connector  66  when the connector  66  inserted in the testing device  40 . Sealing member  51  completely seals or closes second end  78  of connector  66  simulating a connection the connector  66  would make during use. The base member  62  is situated on the platform  60  and aligned under the pneumatic cylinder  50 . The base member  62  includes a receiving surface  84  having at least one receiving member  86  therein for holding or contacting the connector  66  when inserted in the testing device  40 . The base member  62  includes a channel  63  disposed therethrough the receiving surface  84 . An inner bore  68  of the connector  66  aligns with the channel  63  when the connector  66  is inserted in the testing device  40  (see  FIGS. 3 and 4 ). An air line  22  is attached to base member  62  to fluidly connect the channel  63  of the base member  62  and the inner bore  68  of the connector  66  with the decay tester  30 . 
     As shown in  FIG. 2 , connector  66  is received and held by the base member  62 . The connector  66  includes with an inner bore  68  formed between the first end  76  and the second end  78  of the connector. The outside of connector  66  includes a hose barb  72  on second end  78  that cooperates with sealing member  51  of pneumatic cylinder  50 . In one embodiment, base member  62  includes a lip  82 , partially or wholly surrounding connector  66 . Lip  82  prevents the connector  66  from moving while situated in base member  62 . The base member  62  includes a plurality of indents  92  to accommodate clips  94  of the connector  66 . 
     In one embodiment, as shown in  FIG. 3 , the at least one receiving member  86  of the base member  62  is a gasket receiving member  65  or a connector face receiving member  90  or both. As shown in  FIG. 1 , the gasket receiving member  65  is a recess  88  in the receiving surface  84  of the base member  62 . The gasket receiving surface  65  is generally circular and surrounds the channel  63 . The connector face receiving member  90  protrudes from the receiving surface  84  of the base member  62  and receives the connector face  74  of the first end  76  of the connector  66 . The connector face receiving member  90  surrounds the channel  63  and the gasket receiving surface  65 . In operation, as shown in  FIG. 3 , the recess  88  is adapted to receive a testing gasket  71 . The testing gasket  71  cooperates with the gasket  70  of the connector  66 . The connector face receiving member  90  cooperates with the connector face  74  on the first end  76  of the connector  66 . As shown in  FIGS. 3 and 4 , when pneumatic cylinder  50  is actuated or closed, the sealing member  51  contacts and seals the second end  78  at or near the hose barb  72  of the connector  66 , thereby forming a sealed connection between the first end  76  and the second end  78  of the connector  66 . The air line  22  allows a pressure differential from the decay tester  30  to be introduced, either by applying a vacuum or introducing a gas, through the channel  63  and the inner bore  68  of the connector  66 . 
     As shown in  FIG. 4 , in one embodiment, the receiving member  86  of the testing device  40  is a protrusion  87  that extends from the receiving surface  84 . The protrusion  87  surrounds the channel  63  in the base member  62 . When the connector  66  is inserted into the testing device  40 , the protrusion  87  contacts the gasket  70  of the connector  66 , thereby effectively sealing the first end  76  of connector. When, the pneumatic cylinder  50  is actuated and the sealing member  51  seals the second end  78  of the connector  66  a sealed connection is formed between the inner bore  68  of the connector  66  and the air line  22  leading to the pressure decay tester  30 . 
     Once the connector  66  has been placed within the testing device  40  and the pneumatic cylinder  50  is lowered, the sealing member  51  seals the second end  78  of the connector  66  to prevent air flow. Then the decay tester  30  can be activated and work in accordance with generally known principles for conducting leak testing. In one embodiment, the air introduced by the decay tester  30  into the connector  66  simulates the pressure that a liquid would exert against the connector when employed in a filled container. In one embodiment, the decay connector  30  asserts a vacuum on the sealed connection simulating a connection. The decay tester  30  introduces a pressure differential by vacuum or air into the sealed connector  66  to achieve a predetermined set point pressure. The particular set point pressure may vary depending on a variety of factors, including the size of the connector  66  being employed and size of the container with which it will be used, which impacts the pressure that the connector (and the seal within it) is likely to experience in use. 
     After the set point pressure is reached, the decay tester  40  closes off the air flow or vacuum and locks or traps the air within the air line  22 , the base member  62  and the connector  66 . The decay tester  30  then measures the change in pressure over time. If the change in pressure (either loss or gain) exceeds a predetermined threshold within a predetermined period of time, that change of pressure is indicative of a faulty seal or other defect within the connector and the part can be rejected. Generally, the connector  66  is rejected if the measured change in pressure is greater than an industry recognized standard. 
       FIG. 5  illustrates a flow chart of the method  500  of testing a connector  66  for pressure decay. The method  500  includes providing the pressure decay tester system  10 , step  501 , inserting a connector  66  in the testing device  40 , step  503 , and actuating the pneumatic cylinder  50  to cover the connector  66 , step  505 . The method further includes introducing a pressure differential, either through vacuum or the addition of gas into the connector  66  from the decay tester  30 , step  507 , to achieve a pressure predetermined set-point threshold. Once the set-point pressure is reached an initial pressure of the connector is measured at time=0, step  509 . This step is followed by measuring a second pressure at the connector  66  after a predetermined period of time has passed time, time=t, generally 15 seconds to 300 seconds, step  511 , although the pressure may also be measured any number of intervals during that time and in some embodiments may be evaluated continuously. The method  500  then includes comparing the initial pressure (time=0) to the second pressure (time=t), and if there is little or no change from the initial pressure to the second pressure the connector  66  forms a good seal and the connector  66  is passed, step  517 . For a system  10  using vacuum to test the connector  66 , if the second pressure (time=t) is greater than the initial pressure (time=0) beyond a predetermined decay threshold, then the connector  66  is rejected because it is defective or does not form a proper seal, step  519 . For a system  10  that introduces a gas to test the connector  66 , if the second pressure (time=t) is less than the initial pressure (time=0) beyond a predetermined decay threshold, then the connector  66  is rejected because it is defective or does not form a proper seal, step  521 . 
     While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.