Designed for reciprocating motion in hydraulic cylinders, pneumatic cylinders, and linear actuators. Covering 7 sub-categories including piston seals, rod seals, wipers, and guide rings — from standard to extreme high-temperature and high-pressure full-spectrum sealing requirements.
Seal arrangement in a typical double-acting hydraulic cylinder. The piston seal divides the cylinder into the rod-side and cap-side chambers. The rod seal prevents internal pressure leakage. The wiper protects the system from external contamination. Guide rings bear radial loads.
Seven sub-categories covering piston seals, rod seals, wipers, and guide rings. From flagship spring-energized PTFE to general-purpose polyurethane, meeting all hydraulic and pneumatic cylinder reciprocating sealing requirements.
Step-cut PTFE rectangular seal ring with O-ring energizer structure. The O-ring provides initial radial force for low-pressure sealing, while the PTFE glide ring with an extremely low friction coefficient (μ<0.05) enables low breakaway force and long service life. Mounted in piston grooves for bidirectional sealing, capable of withstanding alternating pressure loads without requiring additional back-up ring protection. Reference Trelleborg Turcon® Variseal® design philosophy, combining Glyd Ring® low-friction sliding characteristics with Zurcon® wear durability — the flagship solution for hydraulic cylinder piston sealing.
Flagship Product · Low Friction · Long Life · Glyd Ring® GradeU-shaped cross-section lip seal utilizing media pressure for self-energizing sealing effect — the higher the pressure, the tighter the lip contact. Polyurethane (PU) material provides 3–5 times the wear resistance of general rubber with excellent anti-extrusion performance. NBR for mineral oil-based media, FKM for synthetic hydraulic fluids such as phosphate esters, covering diverse media compatibility needs. Easy installation with standardized grooves, the standard solution for construction machinery and agricultural equipment hydraulic cylinder piston sealing in moderate operating conditions, with outstanding cost-effectiveness.
General-Purpose · Wear-Resistant · Self-Energizing · Zurcon® GradeTrapezoidal cross-section step-cut seal ring, installed at the hydraulic cylinder gland for rod sealing. The innovative stepped lip design creates a pumping effect during the return stroke, efficiently recovering residual oil film back into the system — external leakage is reduced by over 70% compared to conventional U-cups. Combined with an O-ring energizer structure providing initial sealing force, the PTFE glide ring ensures low-friction, long-life operation. Referencing Trelleborg Glyd Ring® and Turcon® Variseal® oil return technology, the pumping recovery capability is industry-leading — the flagship solution for hydraulic cylinder rod sealing.
Flagship Product · Superior Oil Return · Low Leakage · Glyd Ring® GradeU-shaped lip seal for piston rod sealing. During the return stroke, the pumping effect scrapes the oil film back into the system, preventing external leakage. PU material provides excellent wear resistance and self-lubrication, with hardness range Shore A 85–95, offering outstanding cost-effectiveness in moderate pressure and speed conditions. NBR or FKM can be selected for different media requirements. During installation, ensure the lip faces the pressure side to achieve the self-energizing effect. A mature standard solution for industrial hydraulic cylinder rod sealing.
Pumping Effect · Standard Solution · High Value · Zurcon® GradeMultiple V-shaped sealing rings stacked axially to form a seal set, with preload force adjusted by a packing gland for automatic compression force compensation after wear without requiring machine downtime for replacement. Each set typically consists of 3–5 V-rings, with flexible ring count configurable by pressure rating. Suitable for large hydraulic cylinders, hydraulic presses, and forging machinery in low-speed, heavy-load reciprocating sealing scenarios. Particularly effective at high pressures (>25 MPa) where reliability can be enhanced by increasing the number of V-rings. Flexible assembly — individual rings can be replaced independently for low maintenance cost.
Adjustable Preload · Heavy-Duty · Easy MaintenanceDouble-lip wiper design. The outer scraping lip removes external dust, mud, ice, and other contaminants adhering to the piston rod surface. The inner oil-return lip directs residual oil film back into the system, achieving dual scraping and oil-return functions. PU material provides excellent wear resistance. PTFE+O-ring type covers a wide temperature range of -100~260°C for high-temperature or low-temperature hydraulic cylinders. Effectively protects the rod sealing system from abrasive particle intrusion, extending overall seal life by 30–50%. During installation, ensure the scraper lip faces outward and the oil-return lip faces inward.
Dust & Oil Scraping · Dual Action · System Protection · Extended LifeRectangular cross-section wear tape installed in piston or gland grooves to bear radial loads, preventing metal-to-metal contact that could score the cylinder bore or gland inner wall. PTFE type provides extremely low friction coefficient and self-lubricating properties for high-speed, light-load applications. Phenolic fabric type offers high compressive strength (>400 MPa) for high-pressure, heavy-load conditions. POM type provides an economical load-bearing solution balancing cost and performance. Three material grades cover load ratings and cost requirements from standard to extreme — select the matching type based on radial load and speed.
Load-Bearing Guidance · Anti-Scoring · Three Grades · Tiered SelectionOptimal seal stack configurations recommended for different operating conditions. A proper seal combination maximizes system life and reliability while minimizing unplanned downtime risk.
| Operating Scenario | Recommended Seal Stack | Engineering Notes |
|---|---|---|
| Standard Industrial Cylinder | Step-Cut Piston Seal + Step-Cut Rod Seal + PU Wiper + PTFE Guide Ring | All-PTFE bidirectional sealing configuration, low friction, low leakage. Suitable for excavators, loaders, and general construction machinery hydraulic cylinders, balancing performance, life, and cost with standard groove dimensions compatible with ISO 5597. |
| Long-Stroke High-Frequency Cylinder | PU Piston Seal + PU Rod Seal + PU Wiper + Phenolic Fabric Guide Ring | All-polyurethane configuration with self-lubricating wear properties for high-frequency reciprocating motion. Phenolic fabric guide rings provide high load capacity to prevent metal sliding contact at high frequencies. Suitable for injection molding machine clamp cylinders and other high-frequency applications. |
| Ultra-High-Pressure Cylinder (>40 MPa) | Step-Cut Ring + PTFE Back-up + Step-Cut Rod + PEEK Back-up + PTFE Wiper + Phenolic Guide Ring | PTFE/PEEK anti-extrusion back-up rings added on both sides to prevent seal extrusion failure under high pressure. Phenolic fabric guide rings provide >400 MPa compressive strength for ultra-high-pressure radial forces. Suitable for metallurgical extruders, deep-sea equipment, and other ultra-high-pressure applications. |
| High-Temperature Cylinder (>150°C) | PTFE Piston Seal (FKM O-ring) + PTFE Rod Seal (FFKM O-ring) + PTFE Wiper + PTFE Guide Ring | All-PTFE configuration covering up to 260°C. O-ring energizer elastomer selected as FKM (200°C) or FFKM (260°C) to match the actual temperature zone. Suitable for continuous rolling mills, kiln hydraulic systems, and other high-temperature continuous operation scenarios. |
| Water-Based/Low-Lubricity Media | UHMWPE-Modified PTFE Piston Seal + PU Rod Seal + NBR Wiper + POM Guide Ring | UHMWPE filler-modified PTFE jacket enhances self-lubrication in water-based media. PU rod seal offers good compatibility with water-glycol/emulsions. POM guide rings provide economical load capacity. Suitable for mining roof supports, water hydraulic presses, and other water-based hydraulic systems. |
| Low-Temperature Cylinder (<-40°C) | PTFE Piston Seal (VMQ O-ring) + PTFE Rod Seal (VMQ O-ring) + PTFE Wiper + PTFE Guide Ring | PTFE has no embrittlement issues at low temperatures. VMQ (silicone rubber) O-ring energizer retains elasticity down to -100°C. All-PTFE guide rings ensure no brittle fracture risk at low temperatures. Suitable for polar equipment, cryogenic test benches, and other deep-cold hydraulic systems. |
Correct installation is the prerequisite for achieving the design life of a sealing system. The following key points are based on engineering practice — follow them strictly to ensure sealing system reliability.
| Installation Step | Key Requirement | Detailed Description |
|---|---|---|
| 1. Clean & Inspect | No burrs/chips/rust in grooves | All seal grooves and mating surfaces must be thoroughly cleaned. Groove edges require radius R0.2–R0.4 mm, removing sharp edges and burrs to prevent sealing element damage during installation. Rod surface roughness Ra 0.1–0.4 μm, cylinder bore inner wall Ra 0.2–0.8 μm. |
| 2. Apply Lubrication | Pre-lubricate with system hydraulic oil | Apply the system working fluid (hydraulic oil) as installation lubricant on seal lips and groove surfaces. Grease is strictly prohibited — it may cause incompatibility between the seal and the working medium. PTFE seals may be soaked in hydraulic oil for 10 minutes to soften before installation. |
| 3. Piston Seal Installation | Preheat & stretch PTFE seals Check U-cup lip orientation |
PTFE seals (step-cut rings, etc.) are recommended to be heated in an oil bath at 80–120°C for 5–10 minutes before installation to soften them for stretching. They recover to original dimensions after cooling, forming an interference fit. For U-cups, ensure the V-shaped opening faces the pressure side — reverse installation will lose the self-energizing function. |
| 4. Rod Seal Installation | Check step direction Avoid tool scratches |
For step-cut rings, the pumping step of the stepped lip must face toward the system interior (oil return direction). Use a dedicated tapered installation sleeve to guide the seal into the groove. Sharp metal tools must never be used to directly push the seal — this avoids scratching the seal lip or PTFE surface. |
| 5. Wiper Installation | Scraper lip outward, oil-return lip inward | Double-lip wiper orientation is strictly required: the outer dust scraper lip faces the atmosphere, and the inner oil-return lip faces the cylinder interior. Before installation, check that the lips are not reversed or creased. For PTFE-type wipers, ensure adequate clearance between the wiper and rod seal to form an oil return cavity. |
| 6. Post-Installation Verification | Low-pressure trial run + full stroke check | After installation, first conduct a low-pressure (≤5 MPa) reciprocating test run through 5–10 full strokes, checking for external leakage. Once no abnormalities are confirmed, gradually increase pressure to rated working pressure. Within the first 48 hours of operation, periodically check for excessive oil film carry-out on the rod. Adjust the seal combination if necessary. |
Wear performance and friction characteristics comparison of common reciprocating seal materials, compiled from Trelleborg TDS datasheets. Covers volumetric wear rate, dynamic friction coefficient, PV limit, applicable speed, and typical application — providing engineering basis for long-life reciprocating seal material selection.
| Material | Vol. Wear Rate mm³/N·m | Dynamic Friction μ | PV Limit MPa·m/s | Speed m/s | Typical Application |
|---|---|---|---|---|---|
| PTFE+Bronze | 2×10⁻⁶ | 0.08-0.12 | 1.8 | ≤15 | High-Speed Piston/Rod Seal |
| PU (93A) | 3×10⁻⁶ | 0.18-0.25 | 0.5 | ≤0.5 | General-Purpose U-Cup |
| NBR (70A) | 8×10⁻⁶ | 0.25-0.35 | 0.3 | ≤0.5 | Low-Speed Reciprocating |
| FKM (75A) | 6×10⁻⁶ | 0.20-0.30 | 0.4 | ≤0.5 | High-Temp Reciprocating |
| UHMWPE | 0.8×10⁻⁶ | 0.10-0.15 | 0.6 | ≤5 | Water-Based Media |
The full reciprocating seal specification datasheet includes groove dimensional tolerances, material cross-reference, compression rate recommendations, and installation process requirements. Supports quick search by bore series, temperature grade, pressure range, and media type.
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