Pipe Schedule (SCH) is a standardized system that indicates the wall thickness of a pipe. It is used primarily for steel and galvanized pipes to ensure they meet specific pressure, strength, and durability requirements.
How Pipe Schedule Works
The higher the schedule number, the thicker the pipe wall.
Even if two pipes have the same Nominal Pipe Size (NPS) (outer diameter), their inner diameter (ID) will vary based on the schedule.
Pipe schedule affects pressure rating, strength, and weight.
Common Pipe Schedules
The most commonly used schedules for galvanized pipes include:
|
Schedule (SCH) |
Wall Thickness (Inches) |
Common Applications |
|
SCH 10 |
Thinner walls, lightweight |
Low-pressure systems, ventilation |
|
SCH 20 |
Slightly thicker than SCH 10 |
General plumbing, low-pressure lines |
|
SCH 30 |
Medium thickness |
Water supply, structural applications |
|
SCH 40 |
Standard thickness |
Water pipelines, gas lines, construction |
|
SCH 80 |
Thicker walls |
High-pressure applications, industrial use |
|
SCH 160 |
Very thick walls |
High-pressure and extreme environments |
|
XXS (Double Extra Strong) |
Extremely thick |
Specialized applications |
Example: Pipe Schedule & Wall Thickness
For a 2-inch nominal pipe size (NPS 2):
SCH 40 → 0.154" wall thickness
SCH 80 → 0.218" wall thickness
SCH 160 → 0.344" wall thickness
How to Choose the Right Pipe Schedule?
For water and gas pipelines → SCH 40 is commonly used.
For high-pressure applications → SCH 80 or higher is preferred.
For structural or scaffolding purposes → SCH 20 to SCH 40 is used.
