... I use: coal injection ,dust-fall,coal preesure reduction,coal-crack,methane drainage,etcII. Function1. moisture enters into coal mass,releasing some gas,and reducing ... high pressure water injection ,breaking coal mass ,reducing cost, and enhancing the workers feeling of safety;5. use the hole sealing device to ... .VI. Carried Standard :GB/T 10544-2003 Water Injection and Hole-Sealing Device for Coal