ISO/TR 11340 standard is for Rubber and rubber products with Hydraulic hose assemblies External leakage classification for hydraulic systems.
This Technical Report establishes a uniform guide for defining the degree of external leakage on a hydraulic system. 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.
Table 1 - Leakage classification
0 No indication of moisture
1 Non-recurring fluid
2 Recurring fluid that does not result in the formation of a droplet
3 Recurring fluid that results in the formation of a non-falling droplet
4 Recurring fluid where a droplet forms and falls
5 Recurring fluid where the frequency of droplets makes a measurable stream