A pipe schedule (SCH) is not an actual measurement – it is a number based on a wall thickness formula. You can have several pipes with the same outside diameter, but with different schedule numbers – meaning that each schedule represents a different wall thickness. The best way to find these dimensions is to use a Pipe Schedule Chart for nominal pipe size and schedule number.
Combining the pipe schedule and nominal pipe size allows for easy identification and selection of pipes suitable for specific applications, considering factors like pressure requirements, flow rates, and structural integrity.
What is the Difference Between Schedule 40 vs. Schedule 80 Pipes?
The most significant difference between schedule 40 and schedule 80 pipe is the wall thickness, inside diameter, and weight. Of course, all these numbers will vary based on the nominal pipe size. There are also many other pipe schedule numbers as well. For these reasons, it is important to reference a pipe schedule table to ensure that the proper pipe size is selected.
Wall Thickness – Schedule 80 pipes have a thicker wall than Schedule 40 pipes for the same NPS. The increased wall thickness makes Schedule 80 pipes more robust and able to handle higher pressure and heavier loads.
Weight – Schedule 40 pipe weight depends on its length and material composition but is less than Schedule 80 pipe weight due to the thinner wall.
Pressure Rating – Due to its comparatively thinner wall, Schedule 40 pipe has a lower pressure rating than Schedule 80 pipe. Schedule 80 pipes can withstand higher pressure and are commonly used in heavy-duty applications.
Strength and Durability – While suitable for many general-purpose applications, Schedule 40 pipes may not handle extreme pressure or stress as effectively as Schedule 80 pipes. The increased wall thickness of Schedule 80 pipes provides greater strength and durability.