Screw air compressors are positive displacement compressors that rely on the rotation of intermeshing spiral rotors (male and female) to compress gas. Their key advantages include: High efficiency & reliability – Continuous, pulsation-free air supply with stable flow rates.
[pdf] A rotary drilling rig is a construction machinesuitable for hole-forming operations in building foundation engineering. It is mainly suitable for sandy soil, cohesive soil, silty soil, fill layer, and silt layer, so.
[pdf] A rotary table is a mechanical device on a drilling rig that provides clockwise (as viewed from above) rotational force to the to facilitate the process of drilling a . Rotary speed is the number of times the rotary table makes one full revolution in one minute (rpm).
[pdf] 
