PAE Piston Seal Heavy‑Duty PU Combined Seal for High Pressure Hydraulic Cylinder

1. Product Introduction

PAE is a heavy‑duty combined piston seal for high‑pressure hydraulic cylinders. It is not a material grade, but a seal series. Integrated design with PU main seal plus glass‑fiber reinforced back‑up ring, performs well even under relatively large hardware clearance.

2. Construction

1. Main sealing element: C0 polyurethane (PU), Shore A 93, high modulus, good wear resistance, low compression set.
2. Anti‑extrusion back‑up ring: Glass‑fiber reinforced acetyl resin, prevents seal extrusion under high pressure. Installation note: Fits semi‑open groove. Remove sharp edges and burrs on piston before assembly to avoid lip damage.

3. Features

• Excellent anti‑extrusion performance: Hard glass‑fiber reinforced back‑up ring tolerates larger assembly clearance, resists extrusion damage under high pressure, outperforms standard PU seals above 250 bar.
• Superior wear resistance: 93 Shore A high‑hardness polyurethane, long service life under heavy‑load reciprocating motion.
• Limitations: Not for high‑speed operation. Limited media compatibility. Max continuous temperature 100 °C. Not for pneumatic applications.

4. Typical Applications

• Heavy‑duty hydraulic cylinders & construction machinery cylinders
• High‑pressure hydraulic systems with non‑optimal hardware clearance
• Injection molding machines, hydraulic presses, metallurgical heavy‑duty equipment

5. Comparison with Similar Seals

PAE VS SPGW / SPG (PU+PTFE piston seal)

• PAE: Glass‑fiber resin back‑up ring, max 400 bar, speed ≤0.5 m/s, only for mineral oil, medium cost. Better anti‑extrusion for high pressure & large clearance.
• SPGW: PTFE back‑up ring, higher allowable speed, wider media compatibility, but weaker anti‑extrusion capacity compared with PAE.

PAE VS Solid PU Piston Seal

Standard solid PU piston seals normally max out at 210‑250 bar and are prone to extrusion failure with large clearance. PAE with rigid back‑up ring can work up to 400 bar.

6. Selection & Installation Tips

1. Confirm working medium is mineral‑based hydraulic oil. Avoid water‑based or synthetic ester fluids.
2. Requires semi‑open groove; cannot use standard closed O‑ring groove. Refer to DIN 24960 for piston seal groove reference.
3. Cylinder bore surface roughness Ra: 0.4‑0.8 μm recommended.
4. Do not select PAE for continuous temperature above 100 °C. Switch to alternative combined seals for higher temperature conditions.
5. For pressure shock / cyclic pressure conditions, check peak transient pressure; do not run continuously at 400 bar maximum limit.