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Tank Qualification and Mixing Studies

The general approach for qualifying tanks based on requirements and specifications involves several steps. Here is a typical approach:

  1. User Requirement Specification (URS):

    Define the user requirements for the tank, including the intended purpose, capacity, material of construction, design features, and any specific regulatory or industry requirements. Clearly define the user requirements for the tank spray heads, including the desired spray pattern, coverage, flow rate, pressure, and any specific regulatory or industry guidelines that need to be followed. The URS serves as a foundation for the qualification process.

  2. Design Qualification (DQ):

    Evaluate the design of the tank against the URS and applicable standards or regulations. This includes reviewing design drawings, specifications, and documentation provided by the tank manufacturer. Verify that the tank meets the required specifications, such as material compatibility, surface finish, fittings, and safety features. Make sure that the spray heads that are suitable for the specific tank size, shape, and cleaning requirements. Consider factors such as spray angle, flow rate, material compatibility, and the ability to achieve the desired spray pattern and coverage.

  3. Installation Qualification (IQ):

    Verify that the tank is installed correctly and according to the manufacturer's instructions and industry guidelines. This includes ensuring proper positioning, secure anchoring, connection to utilities (if applicable), and compliance with safety requirements. Document the installation activities and verify that the tank is ready for further qualification. Verify that the spray heads and other tank’s components are securely attached, aligned correctly, and connected to the appropriate water or cleaning agent supply lines.

  4. Operational Qualification (OQ):

    Perform operational tests to verify that the tank operates as intended and meets the defined performance criteria. This may include testing the tank's functionality, such as filling, emptying, mixing, or temperature control. Confirm that the spray heads operate according to the predefined parameters. Validate that the spray heads produce the desired spray pattern, coverage, and intensity. Verify that the flow rate and pressure settings are accurate and consistent. Validate the control systems, alarms, and safety features associated with the tank. Document the test results and ensure compliance with the requirements.

  5. Performance Qualification (PQ):

    Validate the performance of the tank by conducting tests under representative operating conditions. This involves running the tank through its intended processes, such as storage, mixing, or transportation, while monitoring critical parameters and assessing performance criteria. Evaluate the tank's performance against predefined acceptance criteria, including factors like temperature control, mixing efficiency, product integrity, and safety. Verify effectiveness of the spray heads in achieving the desired cleaning results. This can be done by performing cleaning trials using worst-case scenarios or representative soils. Evaluate the spray pattern and coverage visually or using appropriate measurement tools to ensure that all critical surfaces are adequately reached by the spray. Document the results and ensure compliance with the requirements.


Mixing studies involves conducting tests under actual operating conditions to validate the performance of the mixing process. Here is a general approach to conducting performance qualification for mixing studies:

  1. Define Performance Criteria:

    Determine the specific performance criteria that will be used to assess the mixing process.

  2. Acceptance Criteria for Mixing Studies:

    The acceptance criteria for mixing studies can vary depending on the specific requirements of the process and the nature of the product being mixed. It is important to note that the acceptance criteria should be established based on scientific principles, regulatory guidelines, and the specific requirements of the product and process. These criteria should be realistic, achievable, and reflective of the desired performance of the mixing process.

    Here are some common acceptance criteria that are often considered for mixing studies:

    1. Mixing Time: The mixing process should achieve the desired level of homogeneity within a specified timeframe. The acceptance criteria may define a maximum mixing time or specify a minimum level of mixing achieved within a certain time.
    2. Mixing Uniformity: The mixture should exhibit a uniform distribution of all components throughout the batch. Acceptance criteria may include limits on the coefficient of variation (CV) or the percentage of samples that fall within a certain range of target values.
    3. Dissolution Rate: In cases where the mixing process involves the dissolution of solid materials, the acceptance criteria may be based on the rate of dissolution. This could include requirements for achieving a certain percentage of dissolution within a specified time period.
    4. Particle Size Distribution: If the mixing process involves the blending of particulate materials, the acceptance criteria may be based on achieving a specific particle size distribution within the mixture. This can be assessed using particle size analysis techniques.
    5. Temperature Control: For processes that require specific temperature control during mixing, acceptance criteria may be defined to ensure that the temperature remains within a specified range throughout the mixing process.
    6. Homogeneity Testing: Acceptance criteria may include conducting homogeneity testing on the mixed product to ensure that it meets predetermined standards. This can involve sampling the mixture and analyzing samples for uniformity.
    7. Product Quality Attributes: Depending on the specific product and its intended use, acceptance criteria may be established based on specific quality attributes such as color, appearance, odor, pH value, viscosity, or other relevant parameters.
  3. Test Plan Development:

    Develop a comprehensive test plan that outlines the specific tests and procedures that will be performed during the performance qualification. This plan should include details such as the test methodology, sampling plan, acceptance criteria, and any special considerations or precautions.

  4. Test Execution:

    Perform the identified tests and procedures according to the defined test plan. This may involve preparing a representative batch of the product or using simulated materials. Ensure that the tests are conducted under normal operating conditions and include variations that are likely to occur during routine production.

  5. Data Collection and Analysis:

    Collect data during the tests, including measurements of relevant parameters and observations of the mixing process. Ensure that the data is recorded accurately and includes all necessary details. Analyze the data to assess whether the mixing process meets the defined performance criteria.

  6. Acceptance Criteria:

    Compare the collected data against the pre-established acceptance criteria. These criteria should be based on scientific or regulatory guidelines and should reflect the desired performance of the mixing process. Determine whether the collected data meets the acceptance criteria.

  7. Documentation and Reporting:

    Throughout the qualification process, maintain detailed documentation of all activities, test results, deviations, and any corrective actions taken. Prepare qualification reports summarizing the qualification activities, findings, and conclusions. Ensure that all documentation is complete, accurate, and meets regulatory requirements.

  8. Review and Approval:

    Have the performance qualification report reviewed and approved by relevant stakeholders, such as quality assurance personnel or subject matter experts. Ensure that any identified issues or deviations are appropriately addressed and resolved.

It's important to note that the specific qualification approach may vary depending on the nature of the tank, its criticality to the process, and applicable regulatory requirements. It is recommended to consult relevant regulations, industry guidelines, and internal quality systems to tailor the qualification approach to the specific tank and facility requirements.