Air break in a drainage connection

An air break is used to indirectly connect a drainage pipe to another drainage pipe. This is commonly used to protect fixtures that are used to prepare food, drinking fountains, ice makers and many other devices that cannot be contaminated.

An air break is created by leaving an unobstructed vertical gap from the discharge of a fixture and the receptacle that receives it. This distance must be at least 25mm (1") or the size of the pipe.

For example:

  • if the drain from an ice machine was 3/4" the minimum air break would be 1" (25mm)
  • if the drain from a steam cooker was 2" the minimum air break distance would be 2" (50mm)

air break for plumbing drains