OPTI-SEAL® UHMW-PE Piston Seal, Dionex

Description

OPTI-SEAL® UHMW-PE Piston Seal for Dionex ICS-3000 and ICS-5000 analytical pumps is a precision-machined replacement piston seal for Thermo/Dionex OEM part number 064946, also commonly searched as 64946.

This seal is designed for ICS-3000 and ICS-5000 analytical versions only. It is not intended for capillary pump versions.

Optimize Piston Seals are among the longest lasting seals on the market. Machined from proprietary polymer blends, Optimize Seals provide excellent high pressure sealing performance. For mostly aqueous or buffered mobile phases, OPTI-SEAL® UHMW-polyethylene is the recommended choice. Specially designed to be more resistant to abrasion and wear than standard polyethylene seals, they can last up to seven times longer under mostly aqueous conditions.

Despite UHMW-PE's durability, it has a coefficient of friction approaching that of PTFE. The homogenous polymer nature leads to less shedding, and when shedding does occur, the larger, more fibrous particles are more easily captured by a filter frit. For a specific recommendation on seal material for your mobile phase, consult our Solvent/Seal Compatibility Table.

Why Choose OPTI-SEAL® UHMW-PE?

• Direct replacement for Thermo/Dionex OEM part number 064946 / 64946
• Recommended for aqueous or mostly aqueous mobile phases
• Engineered for long seal life and high pressure sealing performance
• More resistant to abrasion and wear than standard polyethylene seals
• Lower shedding characteristics than many conventional seal materials
• Designed for labs where uptime, reliability, and clean operation matter

Features

Key Features

• Precision machined
• Long lifetime
• Harder material for improved wear resistance
• Less shedding, with long/stringy fiber particles that are more easily captured by a filter frit
• More resistant to abrasion and wear than standard polyethylene seals
• Recommended for aqueous or mostly aqueous conditions
• Coefficient of friction approaching that of PTFE
• Excellent choice for buffered mobile phases

Best Used For

• Mostly aqueous mobile phases
• Buffered mobile phases
• Ion chromatography applications using compatible solvents
• Preventive maintenance where longer seal life is desired

Compatibility

Compatibility Summary

Important Compatibility Note

This piston seal is for ICS-3000 and ICS-5000 analytical pump versions only. It is not intended for capillary pump versions. Please confirm your system configuration before ordering.

Technical Specs

Installation

Installation Tips

• Confirm that the seal is being installed in a compatible ICS-3000 or ICS-5000 analytical pump.
• Inspect the piston before installing the new seal.
• Look for scratches, hazing, flat spots, salt buildup, or other wear on the piston.
• Wet or pre-soak the seal before installation to help it seat properly.
• Avoid using sharp tools that could scratch the pump housing or damage the seal.
• If a new seal leaks shortly after installation, inspect the piston and confirm the seal was not damaged during installation.

When to Replace the Piston

A worn or damaged piston can prevent a new seal from seating correctly and may cause premature leakage. If the piston is scratched, hazy, flattened, or visibly worn, replacing the seal alone may not solve the problem.

You May Also Need

• OPTI-SEAL® UHMW-PE Wash Seal for Dionex systems
• Seal insertion or forming tool
• Replacement piston if the existing piston is worn or scratched
• Related preventive maintenance components, depending on your service procedure

FAQ

Is this a direct replacement for Dionex 064946?

Yes. This OPTI-SEAL® UHMW-PE piston seal is designed as a replacement for Thermo/Dionex OEM main piston seal 064946, also commonly searched as 64946, for compatible analytical pump systems.

Will this fit my ICS-5000 capillary pump?

No. This seal is for ICS-3000 and ICS-5000 analytical versions only. It is not intended for capillary pump versions.

When should I choose UHMW-PE instead of PTFE?

UHMW-PE is recommended for mostly aqueous or buffered mobile phases. For mostly organic mobile phases or applications requiring broader solvent compatibility, another seal material may be more appropriate. Please consult the Solvent/Seal Compatibility Table for guidance.

Why did my new piston seal leak right away?

Immediate leakage can be caused by installation damage, a dry seal, improper seating, or a worn or scratched piston. Inspect the piston carefully and confirm that the seal was wetted or pre-soaked before installation.

Should I replace the piston at the same time?

If the piston shows signs of wear, scratches, haziness, flat spots, or salt buildup, it should be replaced. A damaged piston can shorten seal life and cause leaks even when a new seal is installed correctly.

What else should I replace during maintenance?

Depending on your system condition and service procedure, you may also need the piston seal wash seal, seal insertion tool, O-ring, piston, or other preventive maintenance components.

Documents

• Seals and Pistons
• Solvent Compatibility Guide for Seals