On April 8, 2019 AMS 2644G1 was published, replacing the 2013 revision F. This revision was completed as part of a standard review cycle, and to address changes in the industry and shortcomings of the previous revision.
Water-Based Penetrants Get Their Own Classification: Method A(W)
One significant change in Revision G is the inclusion of a new class of penetrants, Method A(W). Method A(W) was created to distinguish between Method A penetrants that are water-based, and those that are oil or surfactant based. Previously, all Method A materials were lumped together, regardless of their chemical composition. This change was made to address the increased interest in the market for products that are water-based. Method A(W) penetrants are being defined as products that contain 20% or more water.
Additional changes were made to support the addition of Method A(W) to the specification, including:
- Addition of a flashpoint method that is compatible with aqueous materials.
- A require maximum water content limit of 5% for Method A, B, C, and D penetrants.
Updates to the Method A Penetrant Qualification Criteria
The next big update in Revision G is a significant change to the qualification criteria for Method A penetrants. Since its inception in 1996, the qualification criteria for AMS 2644 have undergone several changes as the lab at Wright-Patterson AFB improved the techniques used to test and approve penetrants. Although the qualification criteria changed, previously approved products were never required to be retested. This practice led to a situation where at least some of the penetrants listed on the Qualified Products List (QPL) would not meet the most current qualification criteria.