The difference between futures trading and spot trading Spot transaction refers to a transaction method in which the buyer and seller perform the obligation of delivery and payment immediately after t...
7 Pipeline inspection, inspection and testing 7.1 General requirements 7.1.1 The construction unit shall inspect the construction quality through its quality inspectors. 7.1.2 The construction unit or...
3.1.20 The location of the expansion joint should be close to the water confluence pipe fittings (Figure 3.1.20), and should meet the following requirements: 1 When the riser passes through the floor ...
Straight seam welded pipe is a general term. It is produced by steel strips. The pipes that are welded by high frequency welding equipment are called straight seam welded pipes. (The name is given bec...
The provisions of the relevant standards for the calibration of power station safety valves are based on the “Steam Boiler Safety Technical Supervision Regulations issued by the Boiler and Press...
1. Classification of steel plates (including strip steel): 1. Classification by thickness: (1) Thin plate (2) Medium plate (3) Thick plate (4) Extra-thick plate 2. Classification by production method:...
The characteristics of SUS304L and SUS304 and the steel pipe material|chemical composition|performance carbon content are different. SUS304L has all the characteristics of SUS304; excellent corrosion ...
1. Preparation for construction 1. The design drawings and other technical documents are complete and approved by the meeting. 2. The construction personnel are trained and familiar with the general p...
l Foreword Pipe fittings are often used when changing the direction, elevation, or diameter of the pipe system, as well as the branch pipe from the main pipe. Pipe fittings refer to the parts used for...
Both 60Si2Mn and 51CrV4 are spring steels with similar mechanical properties. Mechanical properties of 60Si2Mn: σs≥1176Mpa, σb≥1274Mpa, δs≥5%, ψ≥25% 51CrV4 Mechanical properties: σs≥1175Mpa, σb≥1500Mp...
Abstract of the paper: Taking the MK moving coil type fully electric feedback servo valve produced by Japan KYB Industry Co., Ltd. as an example, the characteristics of the moving coil type fully elec...
Preface This standard is based on the European Community Standard EN IO57: 1996 (Copper and copper alloys-Seamless round copper water pipes and copper gas pipes for sanitary and heating installations&...
To put it simply, you first distinguish between iron and steel. Both steel and iron are alloys based on iron and carbon as the main additive element, collectively referred to as iron-carbon alloys. Sm...
At present, with the implementation of the West-East Gas Pipeline in my country, urban gas pipelines have become more popular. Natural gas, liquefied gas, coal gas, and other gas pipeline networks hav...
Abstract: In addition to environmental protection features, geothermal heat pumps also have obvious energy-saving advantages. This article mainly introduces the geothermal heat pump operating cost ana...
Material factors affecting bearing life The early failure modes of rolling bearings mainly include cracks, plastic deformation, wear, corrosion, and fatigue. Under normal conditions, they are mainly c...
1. Copper production (1) International market The main source of copper From the perspective of regional distribution, there are five regions with the richest copper reserves in the world: 1) the west...
Grinding burns and common inspections, Many important maintenance such as products, fruits, crankshafts, consumption methods, printing methods, sales and universal use, etc., need to be grinded after ...
1 Introduction In the chemical control system with a high degree of automation, the regulating valve is used as the terminal execution device of the automatic regulating system, and accepts the contro...
The water supply pipe network distributes the tap water sent from the water plant to thousands of households. Therefore, the water supply pipe network is distributed in every corner of the city, and i...
The rapid development of my country’s economy has led to a huge demand for steel products. Iron ore is used as a material for iron smelting, and the development of its sorting skills is directly...
London Metal Exchange is the largest non-ferrous metal exchange in the world. The price and inventory of London Metal Exchange have an important impact on the production and sales of non-ferrous metal...
front It is said that hematite accounts for a considerable proportion in China’s iron ore resources. Compared with magnetite, most hematite has fine embedded particle size, large mud content and...
Economic analysis summary of split water source heat pump unit By introducing the split water source heat pump air conditioning unit, and comparing it with other central air conditioning systems in te...
2.1 general provisions 2.1.1 the selection of ABS plastic steel pipes for building water supply shall be determined according to the continuous working water temperature and working pressure. Pipes wi...
The technology of replacing pipeline with burst pipe is not a new technology, but it is more and more popular because of the high cost and large interference of other replacement technologies. By digg...
Setting of water supply system 1. Water meter settings In recent years, in order to protect the privacy rights of residents and facilitate property management, outdoor water meters are generally a...
1. Adaptability of concrete admixture to cement (1) The stability of cement ore leads to the stability of mineral components and affects the adaptability of concrete admixture to cement. (2) Cement ma...
With the development of urbanization, the pace of infrastructure construction is accelerating, and with the increasing requirements for environmental protection, drainage pipeline engineering accounts...
Q390C steel plate cutting method Preheating cutting: The most effective way to prevent steel plate from cutting cracks is to preheat before cutting. Before flame cutting, the steel plate is usually pr...
Q390B steel plate welding: The minimum ambient temperature allowed during welding is as follows: 1) Carbon steel and ordinary low alloy steel (Class A-Ⅰ): -10℃ 2) Carbon steel and ordinary low-alloy s...
Q550D steel plate four precautions, how many do you know? The following is a brief introduction to the precautions for the application of the relevant characteristics of the Q550D steel plate. Custome...
How does q345qd steel plate resist wear? 1. The wear-resistant layer resists the wear of the wear medium, and the substrate receives the load of the medium, so it has good impact resistance and can ac...
Q345qd steel plate is a type with relatively high corrosion resistance and rust resistance, and it is at a relatively high level among various steel plates. Because the production is more exquisite, t...