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    Comparison Guide: Sterile Tube Welding vs. Aseptic Connectors

    Are you unsure about the main points of comparison when looking at sterile tube welding vs. aseptic connectors?

    Use the table below to learn more about which solution is best for your unique application needs.


    How do aseptic quick connectors compare vs. sterile tube welding?

    Factor Sterile Tube Welding Aseptic Quick Connectors
    Set-up/Use Time

    Slower vs. aseptic because you have to move sterile tube fuser into position, obtain and install the correctly sized tubing holder, initialize the welder, load tubing, weld, cure time (~4-7 minutes total)

    Set up/use time multiplied by hundreds of welds a week affects overall productivity (e.g., 100 welds/week x 4 minutes = 6.67 hours operator time for welding)

    Aseptic connectors are sterilized and ready to go in tubing/bag assembly, requiring only seconds to connect and actuate

    System Flexibility

    Connection can be made at any time or any place in the tubing

    Welder must be set up for correct tubing size and material

    Tube holders are gauged to specific sizes (e.g., 3/8” x 5/8”)

    Only the same-size tubing (same ID and OD) can be welded together

    Single-use connectors are available that allow for flexibility between different types and sizes of tubing

    No reducers required

    Acquisition/Use Costs

    Capital equipment and ancillary equipment costs range from a few thousand dollars to tens of thousands per welder in each clean room

    Single-use blades cost

    Staff time for set-up and use or downtime if system jams or locks

    Back-up welder if needed

    Maintenance cost

    Higher variable costs than blades

    No capital expense

    Factor Sterile Tube Welding Aseptic Quick Connectors
    Maintenance Requirements

    Welders must be in good working order

    Welder manufacturer’s warranties for regular preventative maintenance of equipment

    Need backup welder during maintenance or out-of-service episodes

    Single-use disposable connectors ready to use

    No maintenance required

    Extractables Package

    Very limited package

    Published studies on the impact of thermal welding process to the flow path of the tubing

    Most manufacturers provide a published extractables package to understand potential effects on cell lines.

    Contamination Risks

    Nonconformance to manufacturer’s recommendations might raise contamination risk due to:

    • Placing tubing with the incorrect diameter in the tube holder. This can cause small pinholes in the weld, due to pinching or squeezing the tubing out of the holder during the weld process
    • Welding different tubing types together, which can lead to weld failure

    Little to no contamination risk because validated aseptic connectors maintain a sterile boundary adjoining two single-use systems.

    Staff Training

    Welders require operator training to ensure proper technique, minimize errors and to safely use the equipment

    Largely connect-and-go, self-contained components with minimal operator training required

    Potential for Operator Error

    Not following manufacturer’s recommendations can lead to the following potential operator errors:

    • Using wrong tube holders for size of tubing
    • Using incorrect tubing: silicone, mismatched TPE
    • Using incorrect tubing type setting on the welder
    • Not using long enough tubing
    • Putting tension on the tubing
    • Inserting the blade incorrectly or reusing single-use blades

    Not following manufacturer’s recommendations can lead to the following potential operator errors:

    • Using process fluids outside of the connector’s chemical compatibility specifications
    • Not fully attaching connector to tubing
    • Applying too much side load
    Materials Considerations

    Minimum tubing lengths might be required to fit tubing into welder

    Must connect same materials (e.g., C-Flex to C-Flex)

    Costly C-Flex tubing is often used for welding

    Silicone can’t be welded because the material burns

    Must know each vendor’s type/size of tubing to ensure compatibility of supplies


    Any tubing length — no minimums required

    Connect to any type of tubing, including silicone, and different types of tubing (e.g., silicone to C-Flex)

    Connect different hose barb sizes (e.g., one side with ¾” hose barb and the other with a ½” hose barb)

    Genderless connectors eliminate the need to carry male/female components

    Connectors from the same family can be interconnected

    Level of Validation

    New sterile tube welders require onsite validation but come with a full weld validation package

    No new product contact material will be introduced into the process

    Aseptic connectors are ready to use and have been validated for material biocompatibility, extractables, sterility, and leakage

    New product contact material might need to be introduced and tested if the connector material has not been used elsewhere in the process

    Wet Welding

    Weld on a new bag at any time or any place in the tubing line (e.g., during a perfusion process). Sufficient tubing length is required to make the weld

    A pre-assembled, sterilized manifold of aseptic connectors facilitates adding additional lines to a process

    Operating Conditions

    Ensure sufficient room and ample tubing to place welder near the process due to the size of the welder

    No extra space, materials or equipment required for connector use

    Product Weight

    ~25 - 35 lbs. for welder

    Negligible weight per connector


    When it comes to sterile tube welding vs. aseptic connectors — which is best for my application?

    When properly applied, either sterile tubing welders or aseptic connectors can create reliable connections.

    The one you choose will depend on the unique features of your application. Factors such as ease of use, potential for downtime, risk for operator error, cost and supply management take on added importance when making this consideration. In most cases, however, aseptic connectors — particularly genderless models—deliver the flexibility, ease of use, reliability and cost efficiencies sought by today’s bioprocessors.


    Have more questions about aseptic connectors?

    You can connect with a member of our sales team by filling out our contact form


    1. “Friday’s Five Questions for the Biotechnology Community” Survey. Aspen Alert. Issue 2441: 8 June 2017.

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