I. Product Overview This product is mainly used for flexible connection coal mine gas drainage pipeline and vacuum between devices, has good bending performance, solve the coal mine gas drainage suction device is connected between the tube and the tightness problems with the installation, ease of use, flame retardant anti-static and so on. Second, the specification model and the meaning I type xjkw-0.78 ?? 76, 102,152,203,250,305,316,400,460,530., Said nominal pressure -0.78Mpa type II xjkw-0.98 76,102,152 , 203,250,305,316,400,460,530 Indicates nominal pressure -0.98Mpa III type xjkw-1.47 76,102,152,203,250,305,316,400,460,530., said nominal To -1.47Mpa three, standards and requirements: HG / T2490-93 MT191-89 Q / HYTJ01-2011 Scope: use strict accordance with the relevant provisions of mine safety