In pressure piping, "schedule numbers" are used to designate the wall thickness of pipes. The schedule number (often abbreviated as "SCH") gives an indication of the pipe's ability to handle pressure and its dimensions. A higher schedule number indicates a thicker wall and hence a stronger pipe.
For example, common schedule numbers include:
- Schedule 40: Standard thickness for many applications (often used in residential plumbing).
- Schedule 80: Thicker than Schedule 40 and used for higher pressure applications.
- Schedule 160: Even thicker and used where very high pressures are expected.
The actual dimensions (outside diameter and wall thickness) of the pipes can be found in standards set by organizations such as ASTM (American Society for Testing and Materials) or ASME (American Society of Mechanical Engineers).
Keep in mind that schedule numbers vary based on the nominal pipe size (NPS), so the same schedule number can represent different wall thicknesses for different pipe diameters. Understanding these specifications is crucial for ensuring the integrity and safety of pressure systems in various industrial applications.