Roller Kelly Bushings
|
Roller Kelly Bushings |
Type |
Driving Method |
Sub-Type |
Applicable Roller Kelly Specifications |
|
|
Square |
Hexagonal |
||||
|
Heavy-sized |
Square drive |
HDS |
2.1/2"-6" |
3"-6" |
|
|
Pin drive |
27-HDP |
3"-6" |
3"-6" |
||
|
20-HDP |
3"-6" |
3"-6" |
|||
|
Medium-sized |
Square drive |
MDS |
2.1/2"-4.1/4" |
3"-4.1/4" |
|
|
M4 |
2.1/2"-5.1/4" |
3"-4.1/4" |
|||
|
Pin drive |
20-MDP |
2.1/2"-4.1/4" |
3"-4.1/4" |
||
|
17-MDP |
2.1/2"-4.1/4" |
3"-4.1/4" |
|||
|
Light-sized |
Square drive |
S4 |
2.1/2"-4.1/4" |
3"-4.1/4" |
|
Roller Kelly Bushings can be classifed as two types based on different ways of drive: Square drive and Pin drive. Also they can be classifed as three types based on different sizes: heavy, medium and light. They are designed and manufactured according to API Spec 7K Standard.
