| Nominal Size | Galvanized Pipe | Stainless Steel Pipe | Copper Tube | |
|---|---|---|---|---|
| Nominal Size | Nominal Size(SCH) | Nominal Size(SU) | Nominal Size | |
| C10 | 10A | 10A | 13 | 13 |
| C15 | 15A | 15A | 20 | 20 |
| C20 | 20A | 20A | 25 | 25 |
| C25 | 25A | 25A | 30 | 32 |
| C32 | 32A | 32A | 40 | 40 |
| Standard | KS D 3507 | KS D 3576 | KS D 3595 | KS D 5301 |