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Swagelok Northwest (US)

Your Authorized Swagelok Sales and Service Center

The names that Swagelok uses for caps and plugs may be confusing because they are the opposite of typical industry terminology. To add to the confusion, Swagelok offers patented tube fitting caps and plugs in addition to pipe caps and plugs.


The name comes from the function rather than appearance. If you have a piece of pipe sticking up, you put a cap on it, same with a piece of tubing. If you have a pipe port, you plug it, same as with a tube fitting port.


To remove some of the mystery, we've included a list of terms for you below


  • Pipe plug: A male NPT fitting, meant to "plug" off a female NPT end connection.
  • Pipe cap: A female NPT fitting, meant to "cap" off a male NPT end connection.
  • Tube plug: Looks more like a pipe cap. This piece replaces the nut and ferrule on a tube fitting and "plugs" the end of a tube fitting.
  • Tube cap: This piece is a bit bigger than a tube plug. It has a nut and ferrule end on it that swages onto a piece of tubing, "capping" off the tubing.


We carry all these items in stock in basic sizing, so if you aren't sure what you need, ask us.