Spiral steel pipe is a kind of steel pipe made by rolling a steel strip into a pipe shape at a certain spiral angle (forming angle) and then welding it. It is widely used in pipeline systems for oil, natural gas and water transmission.
Nominal diameter is the nominal diameter of a pipe, a nominal value of the pipe size. For spiral steel pipe, the nominal diameter is usually close to, but not equal to, the actual inside or outside diameter.
It is usually expressed by DN plus a number, such as DN200, which indicates a steel pipe with a nominal diameter of 200 mm.
Common nominal diameter (DN) range:
1. Small diameter range (DN100 - DN300):
DN100 (4 inches)
DN150 (6 inches)
DN200 (8 inches)
DN250 (10 inches)
DN300 (12 inches)
2. Medium diameter range (DN350 - DN700):
DN350 (14 inches)
DN400 (16 inches)
DN450 (18 inches)
DN500 (20 inches)
DN600 (24 inches)
DN700 (28 inches)
3. Large Diameter Range (DN750 - DN1200)
DN750 (30 inches)
DN800 (32 inches)
DN900 (36 inches)
DN1000 (40 inches)
DN1100 (44 inches)
DN1200 (48 inches)
4. Extra large diameter range (DN1300 and above)
DN1300 (52 inches)
DN1400 (56 inches)
DN1500 (60 inches)
DN1600 (64 inches)
DN1800 (72 inches)
DN2000 (80 inches)
DN2200 (88 inches)
DN2400 (96 inches)
DN2600 (104 inches)
DN2800 (112 inches)
DN3000 (120 inches)
Outer diameter (OD): OD is the diameter of the outer surface of the spiral steel pipe. The OD of a spiral steel pipe is the actual size of the outside of the pipe. The OD can be obtained by actual measurement, usually in millimeters (mm).
Internal Diameter (ID): ID is the diameter of the inner surface of the spiral steel pipe. The ID is the actual size of the inside of the pipe. ID is usually calculated by subtracting twice the wall thickness from the OD in millimeters (mm) ID = OD-2 x Wall Thickness
Application field
Spiral steel pipes with different nominal diameters have different applications in various fields:
1. small diameter Ssaw Steel Pipe (DN100 - DN300): commonly used in municipal engineering for water supply pipes, drainage pipes, gas pipes, etc..
2. medium diameter Ssaw Pipe (DN350 - DN700): widely used in oil, natural gas pipeline and industrial water pipeline. 3. large diameter spiral steel pipe (DN100 - DN300): commonly used in municipal engineering water supply pipeline, drainage pipeline, gas pipeline, etc.
3. Large Diameter Ssaw Pipe (DN750 - DN1200): used in long-distance water transmission projects, oil pipelines, large-scale industrial projects, such as medium transportation.
4. ultra-large diameter Ssaw Carbon Steel Pipe (DN1300 and above): mainly used for cross-regional long-distance water, oil and gas pipeline projects, submarine pipelines and other large-scale infrastructure projects.
The nominal diameter and other specifications of spiral steel pipe are usually produced in accordance with relevant standards and specifications:
1. international standards: API 5L: applicable to pipeline transportation steel pipe, specifies the size and material requirements of spiral steel pipe ASTM A252: applicable to structural steel pipe, specifies the size and manufacturing requirements of spiral steel pipe.
2. national standard: GB/T 9711: applicable to steel pipe for oil and gas industry transportation, specifies the technical requirements of spiral steel pipe. gb/t 3091: applicable to welded steel pipe for low-pressure fluid transportation, specifies the dimensions and technical requirements of spiral steel pipe.
Post time: Sep-02-2024
