What is seamless steel pipe?
Seamless steel pipe (SMLS Pipe) is a kind of steel pipe made by heating steel billet, perforating,
rolling and cooling. Compared with
welded steel pipe, seamless steel pipe has significant advantages in appearance and performance. First, the inner and outer walls of seamless steel pipe are smooth, without welds and scales, which can reduce the resistance of fluid flow, prevent fluid contamination, and ensure higher conveying quality. Secondly, seamless steel pipe has excellent strength and pressure resistance, simpler structure, stronger durability, can withstand higher pressure and temperature, suitable for high pressure and high precision working environment, and longer service life.
Definition of SCH 80
SCH 80 (Schedule 80 Pipe) represents a wall thickness grade, usually refers to seamless steel pipe with thicker wall thickness, especially suitable for occasions with high temperature, high pressure and strong corrosion conditions. SCH 80 piping system is often used in the manufacture of chemical equipment, high pressure pipelines, high temperature heaters and other special piping systems. When designing and installing steel pipe systems, it is crucial to choose the right pipe number to ensure the stability and safety of the pipeline system.
How to determine the actual diameter of SCH 80 seamless steel pipe
To determine the actual diameter of SCH 80 seamless steel pipe, you usually need to refer to the specific product specification sheet, standard documents or consult the manufacturer. Here are a few steps:
1. Understand the meaning of SCH 80
SCH 80 is a representation of the wall thickness grade, which reflects the pressure bearing capacity of the steel pipe. Different wall thickness grades correspond to different wall thickness ranges, so it is necessary to choose according to the actual use scenario of the pipeline.
2. Find relevant standards or specification sheets
You can refer to standard documents such as ASME, ASTM, GB, etc. These documents usually list parameters such as nominal diameter, outer diameter and wall thickness of steel pipes of different specifications. In addition, if SCH 80 is the naming method of a specific manufacturer, you need to find the product specification sheet provided by the manufacturer.
3. Determine the actual diameter
There is a relationship between the nominal diameter (DN) and the outer diameter. By referring to the relevant standards or specification sheets, combined with the known nominal diameter and the wall thickness range of SCH 80, the actual outer diameter can be inferred using a formula (such as "nominal diameter = outer diameter - 2 × wall thickness").
Notes
The naming and representation methods under different standards may be different, so when consulting the documents, you need to pay attention to the matching of the selected standard with the required steel pipe. If you cannot determine it, it is recommended to consult the manufacturer or supplier directly for professional support.
Wall thickness standard of seamless steel pipe
Seamless steel pipes are divided into two categories: hot-rolled and cold-rolled (drawn). Hot-rolled seamless steel pipes include general steel pipes, low-pressure boiler steel pipes, high-pressure boiler steel pipes, alloy steel pipes, etc. In addition to the above types, cold-rolled seamless steel pipes also include thin-walled steel pipes and special-shaped steel pipes. The outer diameter of hot-rolled seamless steel pipes is generally greater than 32mm, and the wall thickness can reach 2.5-75mm, while the outer diameter of cold-rolled seamless steel pipes can be as small as 6mm, and the wall thickness can be as low as 0.25mm. The outer diameter of thin-walled pipes can reach 5mm, and the wall thickness is less than 0.25mm, and the dimensional accuracy of cold rolling is usually higher than that of hot rolling.
Schedule 80 steel pipe dimensions in mm
Nominal size [inches]
|
Outside diameter [inches]
|
Outside diameter [mm]
|
Wall thickness [inches]
|
Wall thickness [mm]
|
Weight [lb/ft]
|
Weight [kg/m]
|
1/8 inches
|
0.405 inches
|
10.3 MM
|
0.068 inches
|
1.73 MM
|
0.24 lb/ft
|
0.37 kg/m
|
1/4 inches
|
0.540 inches
|
13.7 MM
|
0.088 inches
|
2.24 MM
|
0.42 lb/ft
|
0.84 kg/m
|
1/2 inches
|
0.840 inches
|
21.3 MM
|
0.109 inches
|
2.77 MM
|
0.85 lb/ft
|
1.27 kg/m
|
3/4 inches
|
1.050 inches
|
26.7 MM
|
0.113 inches
|
2.87 MM
|
1.13 lb/ft
|
1.69 kg/m
|
1 inches
|
1.315 inches
|
33.4 MM
|
0.133 inches
|
3.38 MM
|
1.68 lb/ft
|
2.50 kg/m
|
1 1/4 inches
|
1.660 inches
|
42.2 MM
|
0.140 inches
|
3.56 MM
|
2.27 lb/ft
|
3.39 kg/m
|
1 1/2 inches
|
1.900 inches
|
48.3 MM
|
0.145 inches
|
3.68 MM
|
2.72 lb/ft
|
4.05 kg/m
|
2 inches
|
2.375 inches
|
60.3 MM
|
0.154 inches
|
3.91 MM
|
3.65 lb/ft
|
5.44 kg/m
|
2 1/2 inches
|
2.875 inches
|
73.0 MM
|
0.203 inches
|
5.16 MM
|
5.79 lb/ft
|
8.63 kg/m
|
3 inches
|
3.500 inches
|
88.9 MM
|
0.216 inches
|
5.49 MM
|
7.58 lb/ft
|
11.29 kg/m
|
3 1/2 inches
|
4.000 inches
|
101.6 MM
|
0.226 inches
|
5.74 MM
|
9.11 lb/ft
|
13.57 kg/m
|
4 inches
|
4.500 inches
|
114.3 MM
|
0.237 inches
|
6.02 MM
|
10.79 lb/ft
|
16.07 kg/m
|
5 inches
|
5.563 inches
|
141.3 MM
|
0.258 inches
|
6.55 MM
|
14.62 lb/ft
|
21.77 kg/m
|
6 inches
|
6.625 inches
|
168.3 MM
|
0.280 inches
|
7.11 MM
|
18.97 lb/ft
|
28.26 kg/m
|
8 inches
|
8.625 inches
|
219.1 MM
|
0.322 inches
|
8.18 MM
|
28.55 lb/ft
|
42.55 kg/m
|
10 inches
|
10.750 inches
|
273.0 MM
|
0.365 inches
|
9.27 MM
|
40.48 lb/ft
|
60.31 kg/m
|
12 inches
|
12.750 inches
|
323.8 MM
|
0.406 inches
|
10.31 MM
|
53.52 lb/ft
|
79.73 kg/m
|
14 inches
|
14 inches
|
355.6 MM
|
0.375 inches
|
11.13 MM
|
54.57 lb/ft
|
94.55 kg/m
|
16 inches
|
16 inches
|
406.4 MM
|
0.500 inches
|
12.70 MM
|
82.77 lb/ft
|
123.30 kg/m
|
18 inches
|
18 inches
|
457.0 MM
|
0.562 inches
|
14.27 MM
|
104.67 lb/ft
|
155.80 kg/m
|
20 inch
|
20 inch
|
508.0 MM
|
0.594 inch
|
15.09 MM
|
123.11 lb/ft
|
183.42 kg/m
|
24 inch
|
24 inch
|
610.0 MM
|
0.688 inch
|
17.48 MM
|
171.29 lb/ft
|
255.41 kg/m
|
32 inch
|
32 inch
|
813.0 MM
|
0.688 inch
|
17.48 MM
|
230.08 lb/ft
|
342.91 kg/m
|
Application of SCH 80 seamless steel pipes
SCH 80 seamless steel pipes are usually used in places that need to withstand high pressure, such as petrochemicals, pipeline transportation, etc. Its thick wall design enables it to work reliably under extreme temperature and pressure conditions, and is widely used in many fields such as chemical, pharmaceutical, aerospace and construction.
Summary
SCH 80 seamless steel pipe has become the preferred material in high-pressure and highly corrosive environments due to its excellent performance and wide application. By understanding its wall thickness standards and related applications, this steel pipe can be better selected and used in actual projects. Seamless steel pipe not only provides higher fluid delivery quality, but also ensures the safety and reliability of the pipeline system due to its high pressure and high temperature resistance. When selecting seamless steel pipes, be sure to pay attention to important parameters such as wall thickness and diameter to ensure its stability and durability in specific environments.