What are the types of copper tubing ordered by wall thickness from light to heavy?

The correct ordering of copper tubing by wall thickness from light to heavy is M, L, K. Copper tubing is categorized into different types, with K being the heaviest and thickest wall tubing, primarily used for underground applications and various industrial settings. L tubing has a medium wall thickness and is commonly used for regular plumbing applications, while M tubing has the thinnest walls and is often used for less demanding applications such as heating and air conditioning systems, where lower pressure is acceptable.

Understanding the distinctions in wall thickness and applications helps ensure that the correct type of tubing is selected for specific use cases, which is essential for maintaining safety standards and performance in plumbing and HVAC systems.