目前,各矿所使用的DZ型单体液压支柱,存在同时使用两种三用阀的情况,即1982年以前生产的老型三用阀和1983年以后生产的新型三用阀。这给各矿在管理、使用和维修单体液压支柱工作造成一定困难。为使各矿使用的老三用阀早日过渡到新三用阀,逐步淘汰老三用阀,本文仅就有关新老三用 At present, the DZ single hydraulic props used by each mine have the situation of using three kinds of three-way valves at the same time, that is, the old three-way valve produced before 1982 and the new three-way valve produced after 1983. This has caused some difficulties for the mines in managing, using and maintaining the hydraulic props of the unit. In order to use the old mine valve used in the early transition to the new three-valve, phasing out the third valve, this article only on the new and old