Cushion Subs used for rotary top drive and the drill string protecting drill pipe thread

Cushion Subs used for rotary top drive and the drill string protecting drill pipe thread

Cushion Subs
 

Cushion subs, also known as float subs or floating cushion subs, are used as a connector between the rotary top drive and the drill string. Cushion subs serve three main functions: provide a means of making up and breaking out threaded connections without damaging threads, decrease the load on the threads of the drill rig components, and absorb shock and reduce vibration and wear of the drill string and drill rig components.
 

Cushion subs work using a sliding spindle, which permits the threads of the mating drill string components to float together or apart during rotation without any axial movement of the rotary drive. Upper and lower urethane cushions decrease the impact on the rotary drive bearings and gear box assembly, thereby prolonging bearing and gear life of the rotary top drive.
 

Other benefits of cushion subs include increased tooling life, reduced equipment downtime, and minimum maintenance requirements. Replacement seal kits are available, and cushion subs may be returned for rebuild or upgrade.
 

Roschen offers three generic cushion sub models: standard duty, deep hole, and heavy duty. We also offer Roschen cushion subs. Contact us today for more information about cushion subs.

Standard Duty
6” OD
Customizable length and thread connection specifications
2” Stroke
70,000 lbs. Hoisting/pulldown capacity

Deep Hole
7” OD
Customizable length and thread connection specifications
3” Stroke
100,000 lbs. Hoisting/pulldown capacity

Heavy Duty
8” OD
Customizable length and thread connection specifications
3” Stroke
100,000 lbs. Hoisting/pulldown capacity

Roschen Model PD6-2
9 1⁄4” OD
10” Shoulder-to-shoulder length
Customizable thread connection specifications
3⁄4” – 1 3⁄4” Stroke
125,000 lbs. Hoisting/pulldown capacity
Weight 165 lbs.

Roschen Model 306130
10” OD
14 1⁄2” Shoulder-to-shoulder length
Customizable thread connection specifications
2 1⁄2” Stroke
200,000 lbs. Hoisting/pulldown capacity
Weight 195 lbs.

Roschen Model 359150
15” OD
17” Shoulder-to-shoulder length
Customizable thread connection specifications
3” Stroke
300,000 lbs. Hoisting/pulldown capacity
Weight 850 lbs.

Roschen Model 306430
18” OD
16 3⁄8” Shoulder-to-shoulder length
Customizable thread connection specifications
2 1⁄2” Stroke
200,000 lbs. Hoisting/pulldown capacity
Weight 1050 lbs.