Establish a uniform guide for defining the degree of external leakage on a hydraulic system. The leakage classifications include dusty and dust-free conditions. The choice of classification is intended to be by visual means rather than with the aid of instruments. It describes the leakage state at the observed time, considering that the state may change over a period of time.
This Recommended Practice covers technology, products, or processes which are mature and not likely to change in the foreseeable future.