TY - JOUR N2 - The article presents the results of tests on SHC-40 hydraulic props equipped with two types of valve blocks: standard (with spring steel cylinder) and BZG-2FS (with gas spring). The research was conducted using impact mass of 4,000 kg and with extreme dynamic load of free fall impact mass of 20,000 kg released from different heights h. The dynamic tests involved a camera with the speed of image capture up to 1,200 frames/sec, which made it possible to register the stream of liquid at the dynamic load and to determine the valve opening time. The study conducted on SHC-40 NHR10 props equipped with two types of valve blocks: a standard and the BZG-2FS fast acting relief, showed that the prop with the BZG-2FS block is more suitable and more effective in the case of areas with high risk of mining tremors and rapid stress relief of a seam. Research methodology developed in the Central Mining Institute combines digital recording technique of pressure in a prop and fast registration of the images, and allows to acquire more accurate analysis of dynamic phenomena in the prop during testing. L1 - http://www.journals.pan.pl/Content/106739/PDF/Archiwum-63-2-15-Pytlik.pdf L2 - http://www.journals.pan.pl/Content/106739 PY - 2018 IS - No 2 DO - 10.24425/122460 KW - individual roof support KW - hydraulic prop KW - yield valves KW - safety valves A1 - Pytlik, Andrzej PB - Committee of Mining PAS VL - vol. 63 DA - 2018.06.30 T1 - Tests on Hydraulic Props Equipped with Yield Valves at Dynamic Load Modelling a Rock Burst UR - http://www.journals.pan.pl/dlibra/publication/edition/106739 T2 - Archives of Mining Sciences ER -