
Safety valves are important safety accessories for boilers, pressure vessels and other pressurized equipment. The safety valve (also known as the pressure relief valve) is automatically opened and closed according to the working pressure (working temperature) of the pressure system, and is usually installed on the equipment or pipeline of the closed system to protect the safety of the system. When the pressure or temperature in the equipment or pipeline exceeds the set pressure of the safety valve, it will automatically open the pressure relief or reduce the temperature to ensure that the medium pressure (temperature) in the equipment and pipeline is below the set pressure (temperature) and protect the equipment and pipeline to work normally. Prevent accidents and reduce losses.
Safety valves are mainly used in steam boilers, liquefied petroleum gas vehicle tankers or liquefied petroleum gas rail tankers, oil production wells, high-pressure bypass steam power equipment, pressure piping, pressure vessels and so on. Safety valves are generally divided into spring-type safety valves, lever-type safety valves, and pulse-type safety valves according to the structure. Among them, spring-loaded safety valves are most commonly used; they are divided into thread-safety valves and flange-type safety valves. Safety valve diameter is generally not large, commonly used in DN15mm-DN80mm, more than 150mm are generally known as large-diameter safety valve.
Through the interpretation of the safety valve, I believe we have a certain understanding of this special valve. Why did the safety valve sales curve keep rising this year? The author visited the pump valve manufacturing company with the problem. The company is a representative enterprise in the safety valve industry and also occupies domestic and international high-end markets. “This year's sales of safety valve of our company compared to previous years, the first quarter almost completed the amount of tasks in the second quarter of last year. According to this year's purchase orders, it is mainly used in the safety of petroleum, petrochemical, high-temperature heat, power stations. Most of the valves are built up in the country this year, and the number of safety valve purchases has also increased. In addition, the number of safety valves exported this year has also increased compared to previous years, such as oil and natural gas extraction in the Middle East, and imports of China this year. The number of valves has also increased. These are one of the reasons that affect the sales of the safety valve market this year." Zhang Yiru, head of the company, said.
In 2013, the market size of the safety valve industry expanded year-on-year, which is an indisputable fact. According to the author's understanding, the number of companies that can now qualify for the production of safety valves in our country is not much, because safety valves belong to the special equipment industry, and the State Administration of Quality Supervision has stricter requirements for qualification review. This year, there is no doubt that the huge demand for safety valves in the market. This brings more wealth opportunities to these companies that are qualified to produce safety valves.
Co2 Gas Shielding Welding Wires/Mild Steel Welding Wire
Gas-shielded, flux-cored arc welding (FCAW-G) is a very popular and versatile welding process. It is used with mild steel, low-alloy steel and other alloy materials in a variety of applications, such as heavy fabrication, structural, shipbuilding and offshore. The two most common (but not exclusive) shielding gases used with the FCAW-G process are carbon dioxide (CO2) and a binary blend of 75% argon (Ar) / 25% CO2. Other blends, such as 80% Ar / 20% CO2, can also be used.
So which shielding gas, 100% CO2 vs. an Ar/CO2 blend, should you choose for your flux-cored welding? Each type offers some advantages and disadvantages. The factors of cost, quality and productivity should be considered when manufacturing decisions are made. The choice of shielding gas affects each of these factors, sometimes in a conflicting way. The merits of the two basic gas options for FCAW on steel applications will be the focus of this article.
Choosing a Shielding Gas for Flux-Cored Welding
Figure 1: Gas-shielded, Flux-Cored Arc Welding
Before getting into the particular advantages of the gas options, it is appropriate to review some basics. It should also be noted that this article only focuses on a few types of gases. As a more comprehensive reference, ANSI/AWS A5.32/A5.32M [Specification for Welding Shielding Gases," prescribes the requirements for shielding gases, defining requirements for testing, packaging, identification and certification. Additionally, it contains helpful information on ventilation during welding as well as general safety considerations.
How Shielding Gas Works
The primary function of all shielding gases is to protect the molten weld puddle and electrode from the oxygen, nitrogen and moisture in air. Shielding gases flow through the welding gun and exit the nozzle surrounding the electrode, displacing the air and forming a temporary protective pocket of gas over the weld puddle and around the arc. Both CO2 and Ar/CO2 blends shielding gases accomplish this purpose.
Some shielding gases make it easier to create the arc plasma, providing a current path for the welding arc. The choice of shielding gas also affects the transfer of thermal energy in the arc and forces on the puddle. For these issues, CO2 and Ar/CO2 blends will behave differently.
Co2 Gas Shielding Welding Wire,Mild Steel Welding Wire,Mild Steel Co2 Mig Welding Wire,Copper Coated Mild Steel Welding Wire
Changzhou Edaweld Trading Company Limited , https://www.edaweld.com