Plugs and caps

The difference between plugs and caps

• Plugs: Have an external (male) thread and are screwed directly into a port (such as that of a valve, column or union) to seal it.
• Caps: Have an internal (female) thread and are screwed onto the end of a fitting or tubing connection to seal the opening.

Installation & material advice

First, it is important to match the material to your system. Choose PEEK or ETFE for biocompatible applications, while stainless steel is preferred for permanent industrial seals.

• Fingertip convenience: Most polymer plugs have a knurled head so they can be tightened by hand.
• Tools: For stainless steel or high-pressure plugs, versions with a hex head are available for use with a wrench.