0102030405
Threaded welded pipe spiral welded pipe
01
Welded Steel Pipe
Welded steel pipes' specifications are usually expressed in terms of outer diameter and wall thickness, and it is necessary to ensure that the hydrostatic test, tensile strength of the weld and cold bending properties comply with the regulations.
Spiral welded pipes can be produced in larger diameters from narrower strips and are generally stronger than straight seam welded pipes, making them suitable for use in large diameter piping systems. The production process for this type of welded pipe consists of welding steel plates or strips after they have been rolled and shaped, and the weld seam can be either straight or spiral, depending on the production process.
Adaptable
Cost-effectiveness
Higher strength
High efficiency
Spiral welded pipes are able to produce large diameter pipes using narrower strip steel, which is very effective in producing large size pipes using limited raw materials.
Compared with the same length of straight seam welded pipe, the weld length of round steel pipe increases by 30-100%. Although the production speed is lower, most of the large diameter welded pipes are spiral welded, which reduces the cost to some extent and improves the cost-effectiveness.
The strength of threaded welded pipe is generally higher than that of straight seam welded pipe, and it can produce welded pipe with larger diameter from narrower billet, and the internal and external welded spiral weld seam increases the steeliness, which makes the pipe more robust.
The production process of spiral welded pipe mainly includes the following steps:
Preparation of raw materials: strip coils are used as the main raw materials, and welding wire and flux are also required. These raw materials are subject to strict physical and chemical tests before being put into use.
Strip treatment: Strips are levelled, trimmed and shaved before forming, as well as surface cleaned and pre-bent edges to ensure the quality and flatness of the strip.
Forming: Strips are formed into the required billet shape by externally or internally controlled roll forming.
Welding: single wire or double wire submerged arc welding technology is used to weld the billet.
Quality Inspection: Ensure 100% non-destructive testing coverage of spiral welds. If there are defects, the system will automatically alarm and spray marking, production workers will adjust the process parameters according to this information to eliminate the defects in time.
Cutting and first inspection: The carbon steel pipe is cut into single pieces using an air plasma cutting machine and a strict first inspection system is carried out. The first inspection includes checking the mechanical properties of the weld, chemical composition, fusion condition, surface quality of the steel pipe and passing non-destructive testing. Only after ensuring that the pipe making process is qualified, can it be formally put into production.
Follow-up: Manual ultrasonic and X-ray review of the weld where there is a continuous acoustic flaw detection marking on the weld. If defects were found, NDT was carried out again by repair until it was confirmed that the defects had been eliminated.
Pipe end machining: The round welded pipe ends are mechanically machined to ensure that end perpendicularity, bevel angle and blunt edges are accurately controlled.
APPLICATIONwelcome
The use of spiral welded pipe is not only limited to oil and natural gas transmission pipelines, but also includes waterworks, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction and many other fields. Specific applications include: water works: for water supply, drainage and other liquid transport. Petrochemical industry: used for the transport of various chemical media. Chemical industry: as the piping of reactor, heat exchanger, tower and tank. Electric power industry: used for high-pressure steam conduit, water-cooled wall pipe and so on. Agricultural irrigation: used for water pipes of irrigation system. Urban construction: used for sewerage, gas, natural gas and other pipelines.
01
Tianjin Lishengda Steel Group
We mainly export to South America (35%), Africa (25%), the Middle East (20%), Southeast Asia (20%). A good corporate reputation won the trust of our customers. In these areas, we have established stable and long-lasting relationships with many customers based on our honesty, high-quality products, reasonable prices, and sincere service.
Tianjin Lishengda Steel Group has always followed international trade practices, adhering to the business philosophy of abiding by contracts, keeping promises, quality service, and mutual benefit. We are willing to sincerely cooperate with friends at home and abroad to develop together.
Contact us
