Spare drive
roller kelly bushing has square shape on the bottom so it can fit into the square
opening of the same type master bushing. It transfers the master bushing’s
rotation to Kelly. It can be classed as three types based on heavy, medium and
light-duty. They are used for 17.1/2 to 49.1/2inch rotary tables. They are
designed and manufactured according to API Spec 7K.
Spare drive
roller kelly bushing has square shape on the bottom so it can fit into the square
opening of the same type master bushing. It transfers the master bushing’s
rotation to Kelly. It can be classed as three types based on heavy, medium and
light-duty. They are used for 17.1/2 to 49.1/2inch rotary tables. They are
designed and manufactured according to API Spec 7K.
Model
|
Duty
|
Drive Type
|
Applicable size of Kelly
|
Square
|
Hex
|
HDS
|
Heavy duty
|
Square drive
|
21/2-6 in
|
3-6 in
|
RTM4
|
Medium duty
|
Square drive
|
21/2-51/4 in
|
3-41/4 in
|
RTS4
|
Light duty
|
Square drive
|
21/2-41/4 in
|
3-41/4 in
|