http://www.welongoiltools.com/cementing/ Cementing The casing cement head with double plugs (called as cement-head) is a common cementing tool used as wellhead unit in all kinds of cementing operation. Comparing to cement-head with single plug, it owns longer cement-head body, and upper rubber plug and lower rubber plug can be put in at same time. The tool owns some advantages such as simple construction, easy operation, high pressure resistant; manifold in common use, flexible in connecting. Especially, the lever type indicator can shows whether rubber plug goes through double plugs cement-head to enter casing so that op