Effectiveness of a powered roof support significantly impacts on the efficiency and safety of a mining process. The main element of the support is a hydraulic leg which transfers loads imposed by the rock mass. One of the basic issues occurring during the extraction process are internal and external leaks of hydraulic systems. A new support system was designed to limit and later eliminate the consequences of such leaks. Its main component is a valve block equipped with two independent check valves. This solution allows to maintain high pressure in both chambers of a leg despite leaks. The article discusses the developed solution and presents preliminary results of bench tests of a leg equipped with the new block and loaded dynamically. The results are promising, and the tested block fulfils its task by maintaining the working pressure in the leg during load.
WIPP supplementary roof support system Room 1, Panel 1: Geotechnical field data analysis report