What is schedule in pipe

In the industrial piping industry, "pipe schedule" refers to the standardized wall thickness of a pipe. Defined by the American National Standards Institute (ANSI), the pipe schedule is critical in determining a pipe’s pressure capacity, mechanical strength, and suitability for different applications.

Each schedule corresponds to a specific wall thickness that varies depending on the nominal pipe size (NPS). Common schedules include:

Schedule 10: Thin wall for low-pressure applications

Schedule 40: Standard wall, widely used in water, gas, and general industrial systems

Schedule 80: Thick wall for high-pressure pipelines

Schedule 160 / XXS (Double Extra Strong): Extra-thick walls for extreme conditions

For instance, a 2-inch pipe with Schedule 40 has a wall thickness of 3.91 mm, while Schedule 80 increases it to 5.54 mm. Although the outer diameter remains the same, a higher schedule means a smaller inner diameter, greater weight, and higher pressure resistance.

Why Pipe Schedule Matters

Choosing the correct pipe schedule is essential for:

Meeting pressure and temperature requirements

Ensuring structural integrity in demanding environments

Complying with industry standards in sectors such as oil & gas, chemical processing, energy, and water supply

Final Thoughts

Understanding pipe schedules helps engineers, buyers, and project managers select the right pipe for safety, efficiency, and cost-effectiveness. When specifying steel pipes for your project, always consider both the nominal size and the appropriate schedule rating.