In oil drilling, a casing head is a simple metal welded or screwed onto the top of the (also known as drive-pipe) or the and forms part of the system for the well. The casing head in a conventional wellhead system is the lowest part of the wellhead assembly and is almost always connected to the surface casing string. It supports the remaining parts of the wellhead and completion equipment. The casing head performs the following functions:
[pdf] Ingersoll-Rand (China) Industrial Equipment Manufacturing Co., Ltd. was founded in 2007 and located in Wujiang District, Suzhou City, Jiangsu Province, China. It is the largest Ingersoll Rand production factory in the Asia-Pacific region. The Ingersoll Rand brand was founded in 1817.
[pdf] The rotating head can be defined as a rotating, low-pressure sealing device used in drilling operations to seal around the drill stem above the top of the blowout preventer stack. Rotating drilling heads are used to safely divert air, gas, dust, or drilling mud away from the rig floor.
[pdf] 
