Instructions for use and maintenance of straight seam steel pipes

Instructions for use and maintenance of straight seam steel pipes

What is a straight seam steel pipe?

Longitudinal seam steel pipe does not refer to a certain type of steel pipe, but a large type of welded pipe. It is made of steel strip. The steel pipe made by using the straight seam high-frequency welding equipment can be called the straight seam steel pipe. In fact, in simple terms, When welding steel plates, the steel pipes whose welds are on the same straight line can be called straight seam steel pipes.

Classification of straight seam steel pipes:

According to different uses and subsequent production processes, it can be roughly divided into scaffolding pipes, fluid pipes, wire sleeves, support pipes, and guardrail pipes. Low-pressure fluid welded pipes are a type of longitudinally welded pipes. After welding, water and gas are transported separately. A water pressure test, so the price of low-pressure fluid pipe is usually higher than the ordinary longitudinal welded pipe, such as 1 inch (DN25) (ie 33.5 * 3.25) welded pipe fluid, welded steel pipe is also called welded pipe, after bending, use steel plate or Steel strip welding can be divided into straight seam welded pipe and spiral welded pipe according to the weld form. According to the application, it can be divided into ordinary welded pipe, galvanized welded pipe and oxygen-blowing welded pipe, wire casing, transformer pipe, thin-walled pipe welding, special-shaped pipe Fusion, and spiral welded pipes.

General-purpose welded pipe: This kind of welded pipe is mainly used to transport low-pressure liquids or fluids. Of course, in addition to these types of steel, there are also some easy-to-weld and weldable steels that can be used to make general-purpose welded pipes. There are some requirements for surface quality. Water pressure, bending, flattening, and other tests.

The double-sided submerged arc longitudinal seam steel pipe is also a straight seam steel pipe. The submerged arc welded steel pipe adopts the JCOE cold forming process, the welding seam adopts welding wire, and the submerged arc welding adopts granular flux. It can produce any specifications with a wall thickness of 325~1420 mm, which can meet the requirements of customers for the size of steel pipes. The domestic standard production usually uses high-frequency straight-seam steel pipes. High-frequency straight-seam steel pipes are usually called original steel pipes. The name of this industry is different from the submerged arc. Welded straight seam steel pipe or thermal expansion high-frequency straight seam steel pipe, their names are often confused.

Precautions in the use of straight seam steel pipes

The installation and use of straight seam steel pipes have strict technological requirements, which need to be carried out according to the actual situation and operating procedures to ensure quality. The construction preparation before the use of straight seam steel pipes, in order to excavate the pipe trench and complete the tube well masonry, it is necessary to install the straight seam Steel pipes, including electric welders, cutting machines, electric hammers, and polishing machines, can be installed only after the equipment is ready.

For the installation of straight seam steel pipes, the pipeline is designed and positioned according to the drawings, the pipe rack is prefabricated according to the site conditions, and the materials are cut according to the design and on-site, and the grooves are polished with a polishing machine and then welded.

Quality requirements for use: branch pipes should not be welded at the weld, and welds should be avoided in the elbow. The deviation per meter for vertical installation should be less than 3 mm, the deviation per meter for horizontal installation should be less than 1 mm, and the weld should be straight and full. There are no burn-through and cracks on the weld surface.