AWRF Recommendations Seek to Clarify Sling Proof Testing
The Associated Wire Rope Fabricators (AWRF) has begun a mission to clarify B30.9's Proof Testing requirement for slings. The ruling states: “Mechanically assembled slings shall be comprised of proof tested components,” and “If untested components are employed, the sling shall be proof tested” In response, AWRF has created a Recommended Practice & Guideline for Proof Test Procedures for Slings.
“B30.9 specifies proof testing,” says Knut Buschmann of Unirope Limited, chairman of AWRF's Testing Committee. “But it doesn't explain how to perform the proof testing.” Concerned over possible confusion on how to perform the tests, the group's Guideline clarifies “how to deal with the wording in B30.9,” Buschmann adds.
The AWRF Recommended Practices and Guideline breaks the proof test down by type of sling, and breaks minimum proof test load down by chain size (Grade 80 or Grade 100 size). It also lists proof test recommendations for newly manufactured slings, repaired slings, and all slings in general.
According to the AWRF document, a proof test is a non-destructive quality control test applied to a chain sling or components of a sling. It is the force that the sling and/or components have withstood under a test in which a constantly increasing force has been applied in direct tension.
AWRF had a draft document of the Recommended Practice open for public review this spring, and plans are to put the draft into an adopted practice at this summer's board meeting, says Buschmann.