Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1412702
24 | September - October 2021 | www . machinerylubrication.com MYTHS ABOUT LUBRICATING GREASE Machinery Lubrication: How were the limits chosen for the HPM specifications? NLGI: A team of grease experts representing large and small manufacturers, additive suppliers, original equipment manufacturers (OEMs) and an expert consultant collabora- tively created the HPM specification. e limits chosen for the tests in the HPM specifications were selected in several ways. When the orig- inal drafts of the specifications were developed, limits were selected based on defining a high level of performance using the decades of expe- rience from global experts in grease lubrication. Then, during an extensive interview process conducted with grease manufacturers, marketers, end-users, GC-LB certification holders and OEMs, the specification team received feedback which led to the philosophy that emerged pertaining to limit-setting: "chal- lenging, but achievable." In some cases, the specification steering committee members identified applicable prod- ucts for the HPM program and then ran tests to validate the proposed limits. e final specification defines a level of performance where HPM greases may have a significant impact on the operational success of a manufacturing plant. Machinery Lubrication: What if my appli- cation calls for better water resistance or higher load carrying capability or some other area? NLGI: Since greases in some applications experience more challenging conditions (e.g., low temperature or exposure to water or corrosive liquids), different sub-categories with additional performance requirements are defined as part of the overall specification. In these sub-categories, a grease must meet the performance of the core HPM grease speci- fication plus the additional testing related to (a) water resistance (+WR), and/or (b) high load-carrying capacity (+HL), and/or (c) salt- water corrosion resistance (+CR), and/or (d) low-temperature performance (+LT) (Figure 1). Machinery Lubrication: How will the end-user ensure that greases of different chemistries certifying to the HPM specifica- tions will be compatible in real application situations? NLGI: Since the HPM and HPM+ specifica- tions are performance specifications, there are no formulation or grease chemistry require- ments to meet the specifications. Because the specifications are "chemistry neutral," there is a possibility for different HPM-certified greases Figure 2 Examples of HPM certification marks.