Contamination, Connectors Groups Convene Prior to ISO Meetings

standards meetings in Nashville and Madison

Last week was a busy week for two of NFPA’s fluid power U.S. technical advisory groups (TAGs). Technical Committee 131’s Subcommittee Six (SC 6) on contamination/filters met in Madison, Wisconsin and Subcommittee Four (SC 4) on connectors/couplings met in Nashville, Tennessee to continue ISO standardization work.

SC 6 Updates

The focus of the filters subcommittee continues to be on ISO 11171, Calibration of automatic particle counters for liquids. The U.S. labs plan to participate in a global interlaboratory test to ensure that this standard meets its technical requirements.

The subcommittee is also gearing up for two additional round robin tests. ISO 4405, Determination of particle contamination level by gravimetric method will be the focus of one test to validate and improve the gravimetric analysis. Testing will also be conducted on ISO 23369, Filter multi-pass test under cyclic flow conditions. Labs from around the world will participate in each round robin to assist in updating these standards. The U.S. is taking the lead in developing the protocol and reporting out the analysis results to the international community on both. The results will help to assist in updating the technical aspects of the standards.

SC 4 Updates

The connectors subcommittee is currently working on 30 separate projects at various stages in the ISO development process. During the meeting, the discussion revolved around a new work item proposal from the U.K. which will try to standardize hose lengths.  The U.S. is also working on proposing another new project for o-ring sealing and pressure ratings.

In October, the ISO mirror subcommittees for contamination and connectors will meet with their global counterparts in Winterthur, Switzerland to continue the consensus-building process of developing fluid power standards. General information on the development process of standards can be found at Specific information on fluid power standardization can be found at

If you are interested in attending a U.S. TAG meeting and/or participating in standards development, please contact Denise Rockhill at

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