The specification requirements of spiral steel pipes should be stated in the import and export trade contract. Generally, it should include the standard brand (model code), nominal diameter, nominal weight (mass), specified length and tolerance value of the above indicators.
China Standard recommends spiral steel pipe series with nominal diameters of 8, 10, 12, 16, 20 and 40mm. Supply length is divided into fixed length and double length. The selection range of rebar length for export in China is 6 ~ 12m, and that for Japanese rebar is 3.5 ~ 10m.
Extended data:
Steel pipes can be divided into:
1, pipe for pipeline. Such as: seamless pipes for water pipes, gas pipes, steam pipes, oil pipelines and oil and gas trunk lines. Water pipes for agricultural irrigation taps and sprinkler irrigation.
2. Pipes for thermal equipment. Such as boiling water pipes and superheated steam pipes of general boilers, superheated pipes, large smoke pipes, small smoke pipes, arched brick pipes and high-temperature and high-pressure boiler tubes of locomotive boilers.
3. Pipes for machinery industry. Such as aviation structural tubes (round tubes, elliptical tubes and flat elliptical tubes), automobile semi-axle tubes, axle tubes, automobile tractor structural tubes, oil cooler tubes for tractors, square tubes, rectangular tubes for agricultural machinery, transformers and bearings.
4. Pipes for petroleum geological drilling. Such as: petroleum drill pipes, petroleum drill pipes (square drill pipes and hexagonal drill pipes), drilling tappets, oil pipes, petroleum casings and various pipe joints, geological drill pipes (core pipes, casings, movable drill pipes, drilling tappets, clamping sleeves and pin joints, etc.). ).
5. Pipe for chemical industry. Such as: petroleum cracking pipes, heat exchanger pipes, chemical equipment pipes, stainless acid-resistant pipes, high-pressure pipes for chemical fertilizers, pipes for conveying chemical media, etc.
6, other departments with tube. Such as: tubes for containers (tubes for high-pressure gas cylinders and general containers), tubes for instruments, tubes for watch cases, injection needles and tubes for medical devices.
Baidu encyclopedia-steel tube