Bushing drilling rig

A wear bushing, or sleeve, is installed in the casing head housing, or indeed in any compact or casing head spool, to protect the hanger landing preparations from damage while the drill string, tools, or other tubulars are run through, or rotated in, the wellhead. . In some systems, the sleeve is held in place by a set of tie-down bolts contained either in the top flange of the housing or in a separate hold-down flange installed between the housing. [pdf]