How to Select a Pneumatic Cylinder: Step-by-Step Guide

1. Define Core Requirements (Load & Force)

• Calculate required force:
  • Thrust force (extension): $F^{thrust}=P\times A\times \eta$
     
    (P = working pressure, A = piston area, η = efficiency ≈ 0.85-0.95)
  • Pull force (retraction): $F^{pull}=P\times (A-A^{rod})\times \eta$
     
    (A rod = rod cross-sectional area)
• Account for load type: Static (e.g., clamping), dynamic (e.g., pushing parts), or shock loads (add 20-30% safety margin).
• Working pressure range: Typical industrial systems use 0.4-0.6 MPa (60-90 psi); confirm system pressure to avoid undersizing.

2. Determine Bore Size

• Use the force calculation to reverse-engineer bore diameter (standard sizes: 16, 20, 25, 32, 40, 50, 63, 80, 100 mm, etc.).
• Example: For $F^{thrust}=5000N$, $P=0.5MPa$, $\eta =0.9$:$A=F/(P\times \eta )=5000/(50000\times 0.9)\approx 0.011m^2$ → Bore ≈ 119 mm (select standard 125 mm).

3. Select Stroke Length

• Choose stroke based on actual movement distance + 5-10 mm reserve (avoids bottoming out).
• Standard strokes: 25, 50, 75, 100, 150, 200, 300 mm (custom strokes available for specialized needs).

4. Specify Speed & Cushioning

• Speed range: Typical 50-500 mm/s (adjust via flow control valves).
  • High-speed (>300 mm/s): Use adjustable air cushions or shock absorbers to reduce impact.
  • Low-speed (<50 mm/s): Avoid excessive friction; select low-friction seals.
• Cushioning options: Built-in rubber cushions (low speed), adjustable air cushions (medium-high speed), or external shock absorbers (heavy loads).

5. Choose Mounting Style

• Axial mounts: Flange (front/rear), foot mount (fixed position).
• Pivoting mounts: Trunnion (mid-body), clevis (end cap) → for angular movement.
• Compact mounts: Threaded rod (direct attachment), bracket mounts (space-constrained areas).

6. Consider Environmental & Media Conditions

• Temperature: Standard cylinders (-20°C to 80°C); high-temperature (up to 150°C) or low-temperature (-40°C) variants for extreme environments.
• Corrosion: Use stainless steel or corrosion-resistant coatings (e.g., for food processing, outdoor use).
• Contamination: Add rod wipers or dust seals (for dusty/wet workshops).
• Air quality: Ensure clean, dry air (use filters/regulators/lubricators – FRL units) to extend service life.

7. Add Optional Features

• Position sensing: Magnetic switches (for end-of-stroke detection, e.g., Reed, Hall-effect).
• Rod type: Solid (standard), hollow (for vacuum applications or passing cables).
• Seals: Nitrile (standard), Viton (high temperature/chemical resistance).
• Special designs: Compact (short body), thin-profile (flat cylinders for tight spaces), tandem (double force), or rotary (angular movement).

Key Checklist for Validation