Drilling derricks and Rig Masts consist of a steel framework with a square or rectangular cross-section. Their purpose is to support the hoisting equipment and rack the tubulars while tripping pipe. The numbe.
[pdf] The advent of cable-tool drilling introduced the wooden derrick into the changing American landscape. Using the same basic notion of chiseling a hole deeper into the earth, along with adding steam power and cl.
[pdf] Screw-type air compressor structure of a unique design, a compact, stylish appearance, high efficiency, small energy consumption, low noise characteristics and long life, is a smart environment-friendly pro.
[pdf] 
