To select a hydraulic cylinder, start with the load and movement required by the machine. Bore and stroke alone are not a complete specification: rod diameter, mounting, speed, fluid and operating temperature also affect suitability.
1. Establish the required push and pull forces
Record the load in both directions, its orientation and the operating cycle. Include acceleration, friction and any external resistance. A vertical lifting duty also needs consideration of load holding within the complete hydraulic system.
The theoretical forces are:
- Extension: F = p × A, using the full piston area.
- Retraction: F = p × (A − Arod), using the annular area.
With pressure p in bar and areas in mm², divide p × area by 10,000 to obtain force in kN. For example, a 50 mm bore has a piston area of approximately 1963.5 mm². At 160 bar, its theoretical extension force is approximately 31.4 kN.
This is a calculation example, not a usable load rating. Friction and back pressure reduce actual output; load dynamics and the installation determine the required design margin.
2. Select bore and rod together
A larger bore provides more force at the same pressure. Rod diameter changes retraction force and speed. Under compression, a long or insufficiently guided rod may buckle, so working stroke, mounting and load guidance must be checked together.
3. Define stroke and installation dimensions
Specify working stroke, closed and extended lengths, mounting dimensions, rod-end thread and port orientation. Check space for hoses, sensors and maintenance. Long-stroke cylinders may require spacers, which increase overall length.
4. Check speed, cushioning and seals
Flow rate and effective piston area determine travel speed. Consider adjustable cushioning when the moving assembly approaches its end stops. Match seal materials to the working fluid and its operating temperature; do not combine separate catalogue maxima without verifying the complete duty.
5. Send a complete selection request
- Push/pull force, pressure, speed and operating cycle.
- Bore, rod diameter, stroke and mounting drawing if known.
- Working fluid, temperature, environment and load guidance.
- Cushioning, sensors, quantity and any ATEX requirements.
Explore Duplomatic HC2 or HC3 cylinders, or send your requirements to IMPEX CONNECT.
Technical references: Duplomatic MS HC2 catalogue 71 000/225 ED and HC3 catalogue 71 200/125 ED.