... Water injection and hole-sealing device for coalUsecoal injection,dust-fall,coal pressure reduction,coal-crack.methane drainage,ect.Function1.moisture enters ... wokers's feeling of safety.5.Use the hole sealing device to efficiently prevent the gas stress and explosion.StrutureIt is ... to purpose of hole sealing and coal breaking.2.The device can be used for several times repeatedly,to unload pressure ...