Section 3 Types, specifications, characteristics and uses of steel pipes

1. According to the outer diameter of the steel pipe
Capillary: 10 mm or less
Small diameter tube: 10.3('/")-102(3'/")mm
Medium diameter tube: 114(4")-508(20") or 660(20") mm
Large diameter tubes: 508 (or 660) mm or more
2. According to the ratio of pipe diameter and wall thickness
Generally, they can be distinguished by the following scopes:
Category: Diameter/Wall Thickness, Wall Thickness/Diameter
Extra-thick wall pipe <5.5 >0.18
Thick-walled pipes 5.5-0.0 0.18-0.12
Standard tube 9.1-20 0.12-0.05
Thin-walled tubes 20.1-50 0.05-0.02
Extra-thin wall tube >50 <0.02
3. By application
(1) Pipeline pipe, which is used for pipeline transportation of water, gas, oil, natural gas and solids;
(2) Structural pipes, which are used in construction, various steel structures and furniture manufacturing;
(3) Machinery manufacturing tubes, used in automobiles, agricultural machinery and machinery manufacturing, etc.;
(4) Boiler and heat exchanger tubes, which are used for boiler water pipes, smoke pipes, heater and preheater tubes, heat exchanger tubes for chemical and petroleum industries, and low-temperature tubes for refrigeration and condensation;
(5) Oil drilling pipes, used for oil drill pipes, casings, etc.