PEEK Shaft End Composite Seal
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The PEEK Shaft End Composite Seal is a high-performance, dual-structure sealing solution designed to provide reliable shaft-end protection for critical equipment in demanding environments.

Key Features & Advantages:

  • Premium Material: Constructed from high-purity PEEK polymer, independently developed by Dalian Allstar Material.

  • Precision Machining: Engineered with strict dimensional accuracy (±0.03mm) and an optimal surface finish (Ra≤0.4μm).

  • Advanced Dual Design: The combination of a primary seal ring and a backup ring effectively compensates for installation deviations.

  • Extended Lifespan: Delivers a service life 3 to 5 times longer than traditional sealing components.

  • Extreme Applications: Excels in challenging conditions, including high-speed rotation, high-pressure fluctuations, and chemically corrosive environments.

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Technical Datasheet · Rev. 2026-07

PEEK Shaft-End Combination Seal

Standards-compliant performance parameters, verified against ISO 527, ISO 899-2, ISO 14644-1 and ASTM D621. All values below are guaranteed minimums unless otherwise indicated.

Core Performance & Technical Parameters
Property Value Test Standard / Condition
Continuous Operating Temperature −60 °C ~ +260 °C ISO 75 (HDT)
Peak Temperature (short-term, < 5 min) +300 °C Intermittent, non-loaded
Static Pressure Capacity ≤ 40 MPa Radial clearance ≤ 0.05 mm, 23 °C
Dynamic Pressure Capacity ≤ 25 MPa v ≤ 10 m/s, lubricated
Linear Velocity ≤ 15 m/s (standard) · ≤ 20 m/s (CF-reinforced) PV limit calculated per DIN 3761
Friction Coefficient — Pure PEEK 0.34 – 0.40 (dry) · 0.10 – 0.15 (lubricated) ASTM D3702, pin-on-disc
Friction Coefficient — 30 % CF PEEK 0.15 – 0.20 (dry) · 0.08 – 0.12 (lubricated) ASTM D3702, pin-on-disc
Tensile Strength — Pure PEEK ≥ 95 MPa ISO 527-2, 23 °C, 50 mm/min
Tensile Strength — 30 % CF PEEK ≥ 210 MPa ISO 527-2, 23 °C, 5 mm/min
Compressive Creep (24 h @ 150 °C, 10 MPa) ≤ 3 % ISO 899-2 / ASTM D621
Hardness (bulk material) Rockwell M99 · equiv. Shore D 87 – 90 ISO 2039-2 / ASTM D785
Mating Shaft Surface Hardness (required) ≥ HRC 45 Applies to counter-face, not to the seal
Chemical Resistance 98 % H2SO4, dilute bases, hydrocarbons, steam & 200+ industrial media ISO 175, 30 d immersion
Dimensional Range Shaft Ø 10 – 300 mm · Groove depth 1.5 – 8 mm Tolerance grade h8 / h9

Application Fields

Petrochemical

High-temperature/pressure pump & compressor shaft seals; crude-oil erosion resistant. Verified service life > 12,000 h at 180 °C / 20 MPa.

Semiconductor

Ultrapure water & CVD equipment. Complies with ISO 14644-1 Class 4 cleanliness; extractable ionic content < 1 ppb.

Food & Pharma

Compliant with FDA 21 CFR 177.2415 & EU 10/2011. Suitable for aseptic filling machines and bioreactor shaft ends.

Aerospace

Hydraulic actuators and fuel-pump shaft seals; qualified through −60 °C ~ +260 °C thermal-cycle tests per RTCA DO-160G.

New Energy

Critical sealing component for lithium-battery electrolyte transfer pumps and hydrogen fuel-cell circulation loops.

Common Failure Modes & Remedies

Leakage

Causes: Stretch > 15 %, roughness > Ra 0.8 µm, particulates > 50 µm.

Remedies: Verify h8/h9 tolerance, polish to Ra 0.4 – 0.6 µm, install ≤ 25 µm filter upstream.

Thermal Overload

Causes: Dry-run > 280 °C, compression > 25 %, cooling loss.

Remedies: Adjust compression to 15 – 20 %, inspect lubricant, restore cooling flow.

Extrusion Damage

Causes: Radial clearance > 0.5 mm combined with frequent pressure surges.

Remedies: Reduce clearance to < 0.2 mm, add anti-extrusion back-up ring.

Essential Procurement Parameters

  1. Shaft diameter & tolerance grade (e.g. Ø 50 h8)
  2. Seal groove dimensions (ID × OD × depth)
  3. Working media, temperature range and pressure
  4. Operating linear velocity & motion type (reciprocating / rotational)
  5. Certification requirements (FDA / ATEX / USP Class VI)

Selection Prerequisites: Counter-face roughness ≤ Ra 0.8 µm · Mating shaft hardness ≥ HRC 45 · Chamfer 0.3 × 45°. Engineering response within 24 hours.

Frequently Asked Questions

Q1 · PEEK vs. traditional rubber seals?

PEEK operates continuously from −60 °C to +260 °C, retains structural strength under aggressive chemistry (e.g. 98 % H2SO4, 200+ media), and exhibits roughly one-tenth the compressive creep of fluoroelastomers, delivering 3 – 5× the mechanical strength.

Q2 · Pure PEEK vs. 30 % Carbon-Fiber reinforced?

Pure PEEK suits low-speed service (< 10 m/s) where toughness is critical. 30 % CF-PEEK offers ~40 % higher rigidity, ~3× wear resistance and higher tensile strength (≥ 210 MPa), ideal for high-speed rotation and elevated PV loads.

Q3 · Can the seal withstand pressure shocks?

Yes. Instantaneous surges up to 3× working pressure (< 100 ms) are tolerated. For repeated shocks (> 10 events/min), a hydraulic accumulator is recommended to protect the seal lip.

Q4 · Cost-effectiveness versus imported brands?

Dalian Allstar Material delivers Victrex-/Solvay-grade performance at 60 – 70 % of imported cost, with ~50 % shorter lead time and localised 24-hour engineering support.