YY/T 0916.20-2019Small-bore connectors for liquids and gases in healthcare applications - Part 20: Common test methods (English PDF)

3.1 Test Method

The determining procedure for evaluating connectors to obtain test results.

3.2 Type Test

The testing of representative samples to determine whether the designed and manufactured connectors meet the requirements of this Part.

NOTE 1. Multiple representative samples may be required, such as testing small-bore connectors produced from each cavity of a multi-cavity mold.

NOTE 2. Adapted from IEC 60601-1:2005, definition 3.135.

A.1 General Guidance

This Appendix provides explanations of some requirements of ISO 80369-20, intended for users familiar with the subject matter of this Part of ISO 80369 but not involved in its development. Understanding these requirements is considered essential for their proper application. Furthermore, given the evolving nature of clinical practice and technology, it is believed that this explanation of existing requirements will facilitate any revisions to this Part as needed to address the evolving clinical practice and technological changes.

The ISO/TC 210 committee attempted to harmonize the functional test methods for connectors in each application area of ISO 80369-20.The appendices to the test methods in ISO 80369-20 describe a specific test procedure applicable to type testing, but modifications to specific test conditions or acceptance criteria are permitted when required for each application area.

Many test methods in ISO 80369-20 are extracted from the ISO 594 1) series of standards. The ISO/TC 210 committee attempted to minimize changes to these test methods. However, changes were made to test methods that included subjective acceptance criteria.

The assembly procedures in each appendix are extracted from ISO 594 and simulate the assembly procedures. Additional instructions are provided for connectors with movable or rotatable locking rings. Each appendix adds requirements for the conditioning of test samples and environmental testing conditions.

NOTE. Manufacturers should also consider using a representative sample of the evaluated small-bore connectors and a representative sample of suitable mating connectors for functional performance testing.

A.2 Specific Clause and Article Explanation

The clause and article numbering in this Appendix corresponds one-to-one with the clauses and articles of ISO 80369-20.Therefore, the numbering is not consecutive.

Clause 1 Scope The ease-of-assembly test method was part of the ISO 594 series of standards. Since it has been removed from the requirements of the various application parts of the ISO 80369 series of standards, this method is no longer present in ISO 80369-20.The acceptance criteria for ease of assembly in the ISO 594 series of standards are subjective. If it is specified as a standardized test method, i.e., "a satisfactory assembly", it lacks repeatability. Furthermore, the intent of the

1) The Chinese document with a consistent correspondence is GB/T 1962. ease-of-assembly test is to ensure that the user can complete the connection using the mating half of the connector. All new connectors added to this series of standards meet the requirements through usability verification. Therefore, the ISO 80369 series of standards no longer includes ease-of-assembly test methods.

The designation of -20 in this Part is to allow for connectors in new application areas. Future development of connectors for these new application areas can utilize ISO 80369-8 to ISO 80369-19 designations.

B.2, C.2, D.2, E.2, F.2, G.2, H.2, I.2 Test Conditions Section 2 of each test method contains requirements for conditioning and environmental testing.

The temperature and humidity conditioning requirements of ISO 594-1 and ISO 594-2 have also been incorporated into the test methods for hygroscopic materials. As these materials are known to absorb moisture from surrounding gases and liquids, this alters the physical properties, dimensions, and performance of the connectors.

The specified temperature range for the test is the same as that specified in ISO 594-1 and ISO 594-2.However, different ranges may be used to evaluate the performance of connectors exposed to heated solutions and outdoor conditions, if specified in the corresponding application parts of this series of standards.

Appendix B Pressure Decay Leakage Test Method This pressure decay test method is a new test method and is not part of the previous ISO 594 series of standards. However, it is based on the leakage test in Appendix A of ISO 594-1:1986. Formula (B.1)

Formula (B.1) used in this test method is derived from Appendix A of ISO 594-1:1986. The following paragraphs discuss the derivation of Formula (B.1) and its operability.

Formula (B.1) yields a leakage exponent, rather than the more conventional leakage rate (change in mass or volume over time). In typical leak tests, the leakage rate is directly proportional to the applied pressure. To compare the results of one test with another, the initial pressure applied needs to be strictly specified. To eliminate this discrepancy, Formula (B.1) includes a term (1/tp) for a standard test result, making all results comparable to the requirements even with different initial pressures applied.

The result of Formula (B.1) is estimated from the approximately linear relationship between pressure and time, rather than from the exact exponential relationship that occurs with compressible fluids and rigid containers. Because of this derivation, the error between the exact and approximate formulas for pressure versus time is less than 4% when the recorded pressure decay does not exceed 22% of the initial pressure.

Formula (B.1) omits temperature correction. Within the specified test conditions and temperature range of 15°C to 25°C, the error is less than ±1%, which is significantly less than the expected variability range of general products and also significantly less than the effect of the approximate linearity of pressure decay.

This test method uses a compressible fluid, typically air or another gas, which is more suitable than a liquid. This is because when using fluids considered incompressible, false leaks caused by the elastic compliance of the connection components under test can significantly bias the results. In this case, the actual effect of the leak bore cannot be detected.

Appendix C Positive Pressure Liquid Dripping Leakage Test Method This liquid leakage test method is the same as that specified in the ISO 594 series of standards.

Appendix D Negative Pressure Air Leakage Test Method This negative pressure air leakage test method is a new test method and is not part of the previous ISO 594 series of standards. The negative pressure test method specified in the ISO 594 series of standards (Part 1 and 5.3 of Part 2) establishes an unspecified negative pressure test pressure and requires the observer to look for continuously forming air bubbles of unspecified size. This test method in ISO 80369-20 was developed during the draft stage of ISO 80369-2 and ISO 80369-6 committees. Formula (D.1) Refer to the explanation of Formula (B.1).

Appendix E Stress Cracking Test Method This stress cracking test method is the same as that specified in the ISO 594 series of standards.

The acceptance criteria have been changed to require a functional leak test following the stress cracking test.

Appendix F Resistance to Separation from Axial Load Test Method The resistance to separation from axial load test method is the same as that specified in the ISO 594 series of standards. The headings and principles are detailed to describe the purpose of the test.

Appendix G Resistance to Torque Separation from Unscrewing Test Method The resistance to torque separation from unscrewing test method is the same as that specified in the ISO 594 series of standards. The headings and principles are detailed to describe the purpose of the test.

Appendix H Overload (Slippage) Resistance Test Method The overload resistance test method is the same as that specified in the ISO 594 series of standards.