(1) The importance of the structure of heavy industrial structures, large-span structures, high-rise or super-high-rise civil construction structures or structures and other important structures, should consider the selection of good quality seamless steel tubes, the general industrial and civil architecture, according to the nature of the work can be selected by the ordinary quality of seamless steel tubes.

The standard provisions in piping, mechanical properties, physical properties, the use of performance and process performance indicators, corresponding to the different steel grades. Performance metrics vary greatly. Mechanical properties: Tensile strength, yield intensity, elongation, hardness, impact energy; physical properties mainly refer to the grain size.

Hot dip galvanized square tube is used square tube plate or strip after curl forming in the hot dip galvanized pool through a series of chemical reactions forming the square tube; can also be hot-rolled or cold rolled galvanized steel strip after colda hollow square cross-section bend, then the high-frequency welded steel pipe.

　　This problem about flat welding flanges has always been a topic of concern. It is related to the production costs or economic benefits of companies and enterprises. Therefore, the sealing principle of flat welding flanges is constantly improving and perfecting.

　　The manufacturing process of the high-pressure elbow firstly welds a polygonal ring shell with a polygonal cross section or a multi-edge fan shell closed at both ends. After the internal pressure is filled with the pressure medium, the internal pressure is applied, and the cross section changes gradually from the polygon under the action of the internal pressure.

Because the elbow has good comprehensive performance, it is widely used in chemical engineering, construction, water supply, drainage, petroleum, light and heavy industry, refrigeration, sanitation, plumbing, fire protection, electric power, aerospace, shipbuilding and other basic projects.

WCB (carbon steel), LCB (low temperature carbon steel), LC3 (3.5% nickel steel), WC5 (1.25% chromium 0.5% molybdenum steel), WC9 (2.25% chromium), C5 (5% chromium 0.5% molybdenum), C12 (9% chromium 1% molybdenum), CA6NM (4 (12% chromium steel), CA15 (4) (12% chromium), CF8M (316 stainless steel), CF8C (347 stainless steel), CF8 (304 stainless steel), CF3 (304L Stainless steel), CF3M (316L stainless steel), CN7M (alloy steel), M35-1 (Monel), N7M (Hast nickel alloy B), CW6M (Hasta nickel alloy C), CY40 (Inconel nickel alloy) etc.

There are many types of pipe fittings, which are classified according to their use, connection, materials, and processing methods.

The water supply of the room is important to adopt steel and conical steel pipes to cause “secondary pollution” in pipeline transportation. In daily life, the quality of drinking water and the safety of water pipes are the core of people's lives. Double-sided submerged arc welding straight seam steel pipe

1. Apparent requirements for straight seam steel pipe welds Before the non-destructive testing of straight seam steel pipes, the inspection of the weld appearance should meet the requirements. The general requirements for the appearance of straight seam steel pipe welds and the surface quality of welded joints are as follows: the appearance of the weld should be well formed, and the width should be 2 mm per side over the edge of the groove. The height of the fillet of the fillet weld shall comply with the design regulations and the shape shall be smooth transition.

Acceptance 1.1 The quality inspection and acceptance of straight seam steel pipes shall be carried out by the technical quality supervision department of the supplier.

The high-frequency resistance welded steel pipe is different from the ordinary welded pipe welding process. The weld is made of the base material of the steel strip body, and the mechanical strength is better than that of the general welded pipe.

Two ways of welding high-frequency straight seam welded pipe units: contact welding and induction welding.

Drainage straight seam steel pipes, sewage pipes, and drainage pipes are systems consisting of pipe channels that collect and discharge sewage, wastewater, and rainwater, and their ancillary facilities. Including the main pipe, the branch pipe and the pipe leading to the treatment plant, whether it is built on the street or anywhere else, as long as it is a drainage pipe, it should be counted as a drainage pipe.

Large diameter steel pipe can be used for straight seam pumping sand used, taking widely used in sand mining machinery, dredging, salt extraction, Chati iron, steel can be called pumping sand , sand pumping pipeline , pumping sand with steel.

Purchasing this industry should be relatively rich, but it is also very difficult to do. They also carry a lot of hardships. The materials that come out of the project also have many things that they have never seen before. They also have to study and study. Sewage steel pipe purchase should pay attention to the points.

Technical requirements and quality inspection of straight seam pipe According to the standard of GB3092 "welded steel pipe for low pressure fluid transportation", the nominal diameter of welded pipe is 6~150mm, the nominal wall thickness is 2.0~6.0mm, and the length of welded pipe is usually 4~10m. It can be factory-made according to the length of fixed length or multiple length. The surface quality of steel pipe should be smooth, and there are no defects such as folding, cracking, delamination and lap welding.

Large-diameter straight seam steel pipes can be used as dredging pipes , which are mainly used to clean steel pipes conveying sediment, mud and other mixed debris.

What is a petroleum steel pipe? The petroleum steel pipe is a long steel with a hollow section and no joints around, and the petroleum cracking pipe is an economical section steel.

What are the precautions for using oil casings? The oil casing is used to support the oil and gas well walls to ensure the normal operation of the entire well after the drilling process is completed. Each well is based on different depths of drilling and geology, using several layers of casing. After the casing is down, the cement is to be cemented. It is different from the oil pipe and the drill pipe and cannot be reused. It is a disposable material.

The history of oil casing development. After nearly 20 years of hard work, China's oil casing production has gone from scratch, from low price to high price, from low steel grade to API series products to special demand non-API products, from quantity to quality are close The level of foreign oil casing products. The domestic market share of China's oil well pipes has exceeded 80%, and has been a net export product for many years.