This series of car mounted screw compressors provides a robust, high flow, oil-free, contactless, and low maintenance solution designed specifically for pollution-free emissions of various types of dry bulk products.
[pdf] They are used to keep the pressure in a tank between a pre-set lower and upper pressure. When the tank pressure crosses the upper or lower limit, an electrical switch is operated. Normally Closed (NC) switch.
[pdf] A down-the-hole drill, usually called DTH by most professionals, is basically a screwed on the bottom of a . The fast hammer action breaks hard rock into small cuttings and dust that are evacuated by a fluid (air, water or ). The DTH hammer is one of the fastest ways to drill hard rock. The system is thought to have been invented independently by Stenuic.
[pdf] 
