Keterangan :

Roller kelly bushing is a necessary tool for drilling. It is to drive kelly spinner by matching with master bushing. Through rotating of four rollers, the friction between rollers and kelly pipe is reduced and service life is extended. For different sizes of kelly pipe and hexagonal pipe only need to change corresponding rollers. To connect with rotary table, there are two transmission styles ( square and pin) . The product is designed and manufactured according to API Spec 7K “ Specification for Drill Equipment� .