... :Hole sealing:30~120mm Water injection and hole-sealing device for coalUsecoal injection,dust-fall,coal pressure reduction,coal-crack.methane ... sealing and coal breaking.2.The device can be used for several times repeatedly,to unload pressure after water injection,it ... the hole device with pressure.4.Allow no person in front of the working device. Water Injection And Hole-sealing Device ...