Date: 14-MAY-2020   Last Updated: 8-NOVEMBER-2025

How to Achieve Optimal Seals When Crimping Caps on Vials

Proper crimping is essential to ensure a secure, airtight seal on serum finish vials. An improperly crimped cap can lead to compromised sample integrity, contamination, or leakage. Follow the steps below to achieve consistent, high-quality seals every time.

Key Considerations for Effective Crimping

1. Use a Calibrated Crimping Tool

   • Ensure your crimping tool is properly calibrated.
   • The crimper chuck should be adjusted approximately every 50 crimps using the adjustment tool provided by the manufacturer.

2. Inspect the Seal After Each Crimp

   • Check for rotation: The cap should not spin freely on the vial. A spinning cap indicates an inadequate seal.
   • Examine the septa: The septum should remain flat. Avoid dimpling or concave deformation, which may affect sample access and integrity.
   • Verify the crimp edge: The aluminum cap should be evenly bent under the vial’s neck (serum finish) to ensure a uniform seal.

Best Practices

• Perform regular maintenance and cleaning of your crimping tool.
• Practice on test vials when adjusting the crimper to avoid wasting sample containers.
• Document calibration intervals and inspection results as part of your lab’s quality assurance process.