Stokes 61B by-pass mechanical boosters are designed to be used in conjunction with rotary-piston, dry vacuum, rotary vane and liquid ring pumps to increase pumping speed at working pressures and shorten pump down time significantly.
| Technical data | |
| Displacement | |
| V belt (2750 rpm) | 3375m3h-1 / 2000ft3min-1 | 
| Direct drive (1800 rpm) | 2210m3h-1 / 1300ft3min-1 | 
| Direct drive (3000 rpm) | 3685m3h-1 / 2170ft3min-1 | 
| Direct drive (3600 rpm) | 4420m3h-1 / 2600ft3min-1 | 
| Inlet/outlet flanges | 8” ASA/ANSI flange | 
| Motor power EU/Asia | 18.5kW | 
| Motor power US TEFC | 10/25hp | 
| By-pass available | Yes | 
| Cooling method | Air cooled | 
| Oil capacity (horizontal flow) | 1.9 litre / 0.51gal | 
| Oil capacity (vertical flow) | 4.1 litre / 1.1gal | 
| Max temp rise | 135°C / 275°F | 
| Max discharge temp | 191°C / 375°F | 
| Weight bare shaft | 284kg / 625lbs | 
| Weight TEFC direct drive | 530kg / 1170lbs |