Stainless steel pipe is manufactured in a wide range of sizes, the standard sizes for outside diameter include 1 inch, 2 inch, 3 inch, 4 inch, 5 inch, 6 inch, 8 inch and 10 inch, etc. The outer diameter of a stainless steel pipe is the diameter of the outside of the pipe, usually denoted by the letter D or Φ. The outer diameter is one of the important parameters of pipeline dimensions and is used to determine the size and suitability of the pipeline. The outer diameter can be obtained by measuring with tools such as vernier calipers.
Pipes are designed and manufactured following relevant standards and codes, such as ASME B36.10 and ASME B36.19, which specify pipe sizes and wall thicknesses for different NPS and Schedules.
The materials for stainless steel pipe include 304 stainless steel and 316 stainless steel. 304 stainless steel has good corrosion resistance, heat resistance, low-temperature strength and mechanical properties, and is suitable for use in general environments. While 316 stainless steel has better corrosion resistance and heat resistance, suitable for more harsh environments, such as marine and chemical environments.
Stainless Steel Pipe Sizes
| Nominal Size | OD | Wall Thickness, SCH | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NPS | DN | mm | 5S | 10S | 40S | 80S | |||||||||||||
| 1∕8 | 6 | 10.3 | – | 1.24 | 1.73 | 2.41 | |||||||||||||
| 1∕4 | 8 | 13.7 | – | 1.65 | 2.24 | 3.02 | |||||||||||||
| 3∕8 | 10 | 17.2 | – | 1.65 | 2.31 | 3.2 | |||||||||||||
| 1∕2 | 15 | 21.3 | 1.65 | 2.11 | 2.77 | 3.73 | |||||||||||||
| 3∕4 | 20 | 26.7 | 1.65 | 2.11 | 2.87 | 3.91 | |||||||||||||
| 1 | 25 | 33.4 | 1.65 | 2.77 | 3.38 | 4.55 | |||||||||||||
| 1 1∕4 | 32 | 42.2 | 1.65 | 2.77 | 3.56 | 4.85 | |||||||||||||
| 1 1∕2 | 40 | 48.3 | 1.65 | 2.77 | 3.68 | 5.08 | |||||||||||||
| 2 | 50 | 60.3 | 1.65 | 2.77 | 3.91 | 5.54 | |||||||||||||
| 2 1∕2 | 65 | 73 | 2.11 | 3.05 | 5.16 | 7.01 | |||||||||||||
| 3 | 80 | 88.9 | 2.11 | 3.05 | 5.49 | 7.62 | |||||||||||||
| 3 1∕2 | 90 | 101.6 | 2.11 | 3.05 | 5.74 | 8.08 | |||||||||||||
| 4 | 100 | 114.3 | 2.11 | 3.05 | 6.02 | 8.56 | |||||||||||||
| 5 | 125 | 141.3 | 2.77 | 3.4 | 6.55 | 9.53 | |||||||||||||
| 6 | 150 | 168.3 | 2.77 | 3.4 | 7.11 | 10.97 | |||||||||||||
| 8 | 200 | 219.1 | 2.77 | 3.76 | 8.18 | 12.7 | |||||||||||||
| 10 | 250 | 273.1 | 3.4 | 4.19 | 9.27 | 12.7 | |||||||||||||
NPS
NPS is the standard size of pipe, usually measured in inches. For example, NPS 1/2 indicates that the pipe has a nominal diameter of 1/2 in. NPS sizes range from 1/8 to 48 in. and each size has a corresponding outside diameter (OD) and wall thickness (WT). For example, NPS 1/2 has an OD of 0.84 inches.
Schedule
The schedule represents the wall thickness series of a pipe and is used to specify the wall thickness at a given NPS. The larger the value of the Schedule, the thicker the wall thickness and the greater the pressure-bearing capacity of the pipe. Common Schedule series include Sch 5S, Sch 10S, Sch 40S, Sch 80S, and so on. For example, an NPS 1/2 pipe has a wall thickness of 0.105 inches at Sch 40S and 0.134 inches at Sch 80S.
Nominal Diameter
Nominal diameter (DN) is a standard size specified for the convenience of design, manufacture and maintenance, and is used to indicate the common caliber of pipes and their accessories. Nominal diameter is not equal to the actual outer diameter or inner diameter of the pipe, but close to the inner diameter of the pipe. The use of nominal diameter is conducive to the standardization of parts and components to facilitate the design, manufacture, repair and management, reducing manufacturing costs. For example, the DN15 stainless steel pipe outside diameter is usually 21.3mm
Stainless Steel Grade Available
Stainless Steel Pipe Standard
Metric Stainless Steel Pipes Sizes
- 1/2 inch pipe Sch 40S is 21.33 mm for OD and 2.77 mm for thickness
- 3/4 inch pipe Sch 40S is 26.7 mm for OD and 2.87 mm for thickness
- 1 inch pipe Sch 40S is 33.4 mm for OD and 3.38 mm for thickness
- 1 1/4 inch pipe Sch 40S is 42.2 mm for OD and 3.56 mm for thickness
- 1 1/2 inch pipe Sch 40S is 48.3 mm for OD and 3.68 mm for thickness
- 2 inch pipe Sch 40S is 60.3 mm for OD and 3.91 mm for thickness
- 2 1/2 inch pipe Sch 40S is 73 mm for OD and 5.16 mm for thickness
- 3 inch pipe Sch 40S is 88.9 mm for OD and 5.49 mm for thickness
- 4 inch pipe Sch 40S is 114.3 mm for OD and 6.02 mm for thickness
- 5 inch pipe Sch 40S is 141.3 mm for OD and 6.55 mm for thickness
- 6 inch pipe Sch 40S is 168.3 mm for OD and 7.11 mm for thickness
- 8 inch pipe Sch 40S is 219.1 mm for OD and 8.18 mm for thickness
- 10 inch pipe Sch 40S is 273.1mm for OD and 9.27 mm for thickness
Pipe Size and Tube Size Difference
Tube Size
The dimensions of a Tube can be specified as any two of the three: outside diameter, inside diameter, and wall thickness. For example, the dimensions of a round tube can be expressed as outer diameter and wall thickness, or inner diameter and wall thickness. For example, the dimensions of a round Tube can be expressed as an external diameter of 10 mm and a wall thickness of 2 mm.
Pipe Size
The pipe is sized to more stringent standards, conforming to the nominal sizes listed in ASNI B36.10 and B36.19 (for stainless steel.) Pipe diameters are indicated by the NPS ( Nominal Pipe Size ) number, which does not correspond to the actual outside diameter. For example, the actual outside diameter of NPS 8 is 8.625 inches. For example, the actual outside diameter of the NPS8 is 8.625 inches, and the wall thickness varies according to Schedule No. ( e.g., STD, XS, XXS).