Since 2003, HardRock Infrastructure Services has been taking on the kinds of projects others will not touch. What started with one man, one rig, and a pocketful of credit cards quickly evolved into one of the top providers of horizontal directional drilling (HDD) services in the United States.
[pdf] Compared with the drill and blast method, TBM tunnelling has significant advantages with high construction efficiency, low project cost, conducive to environmental protection, favorable stability contr.
[pdf] Flange end ball valves are widely used in mining due to their ability to provide precise fluid control and tight shutoff in high-pressure mining environments with hydraulic valves.The floating ball mechanism allows the ball to move slightly under pressure, pressing against the downstream seat for a secure seal.
[pdf] 
