Colour Coded Silicone Ball Lock Post O-Rings - Pack of 10

Pack of 10 replacement colour coded ball lock keg post O-rings.

These replacement O-rings are designed for ball lock posts commonly found on Cornelius-style kegs and are one of the simplest upgrades you can make to improve your workflow.

Post O-rings are a frequent source of gas and liquid leaks, and replacing them periodically is good preventative maintenance. In many cases, a slow leak or loss of pressure can be traced back to a worn, flattened, or chemically degraded post O-ring rather than the disconnect itself. It's always handy to have some backup o-rings.

These O-rings are colour coded to match Duotight ball lock disconnects, making post identification immediate and intuitive:

Red: Gas post
Yellow: Liquid post

The colour coding removes guesswork entirely. No more squinting at “IN” and “OUT” markings or lining up notches while you’re mid-clean or mid-keg swap. At a glance, it’s obvious which post is gas and which is liquid.

Includes:

• 5 × Red (Gas) Post O-Rings
  
• 5 × Yellow (Liquid) Post O-Rings

Why Silicone and Not Low₂ O-Rings?

A common question is why Low₂ O-rings aren’t used on keg posts. The answer comes down to seal geometry and material behaviour.

Post O-rings form a radial seal, which relies on elastic recovery (spring-back) to maintain a tight seal after repeated connect and disconnect cycles. Low₂ materials retain more compression memory, meaning that once deformed, especially under cold conditions, they may not fully rebound if the disconnect is reattached at a slightly different orientation. 

Silicone, by contrast, has:

• Lower compression set
  
• Better elastic recovery
  
• Consistent sealing performance after repeated use

Low₂ O-rings are excellent for face seals, such as keg lid (hatch) O-rings, where they can tolerate very high pressures and reseat easily even after compression. However, they are not ideal for radial sealing applications like post O-rings.