Types of Copper Pipe

Copper pipe and tube comes in a variety of types, with different wall thicknesses, ductility and intended used. The difference between copper pipe and copper tube is the the way the diameter of the pipe is measured. Copper tube is measured by outside diameter (OD) whereas copper pipe is measured by inside diameter (ID). Depending on the plumbing job you are doing, local and national plumbing codes will dictate which type of copper pipe is acceptable.

Type L copper pipe

Type L copper pipe and tube has a thicker wall than type M and DWV pipes making it the preferred choice for longevity. There are two kinds of type L; Hard, and soft temper. Type L will be marked with blue along the pipe or tubing.

Hard temper type L plumbing applications include:

  • Above ground water distribution
  • Above and below ground drainage and venting systems
  • Building sewer

Soft temper type L plumbing applications include:

  • Water service pipe
  • Water distribution above and below ground

Type M copper pipe

Type M copper pipe and tubing is commonly used in residential plumbing because it has thin walls and can be produced and sold at a much lower cost. For water distribution longevity type M is not recommended. Type M copper is also better for heating applications because of the thin wall thickness. Type M is identified with RED markings along the pipe.

Hard temper type M plumbing applications include:

  • Above ground water distribution
  • Above ground drainage systems

Soft temper type M shall not be used in plumbing systems.

Type K copper pipe

Type K copper pipe and tube is the most robust of the four types because it has the largest wall thickness. Type K comes in hard and soft temper and will be identified by green markings. Type K copper can be used for many other applications such as: Fuel, gasses, HVAC, fire protection systems and vacuum systems to name a few.

Hard temper type K plumbing applications include:

  • Above ground water distribution
  • Above and below ground drainage and venting systems
  • Building sewer

Soft temper type K plumbing applications include:

  • Water service pipe
  • Water distribution above and below ground

DWV copper pipe

DWV copper pipe is used for drainage waste and vent (DWV), above ground only and is identified by yellow markings.