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Features of Stainless Steel Valves

Generally speaking, stainless steel valves are valves made of stainless steel. They are classified according to the stainless steel material grade of the valve body. They are mainly 301, 304, 316, 304L, 316L, etc. According to international standards, they can be divided into CF8, CF3, CF8M, CF3M, the quality of the material

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

CF8<CF3<CF8M<CF3M. Because stainless steel has strong corrosion resistance, is easy to form, has high compatibility, and can remain strong in a wide temperature range, many advantages make stainless steel valves widely used in heavy industry, light industry, daily necessities industry and architectural decoration industry. middle.
Stainless steel refers to steel that is resistant to corrosion by weak corrosive media such as air, steam, water and chemical corrosive media such as acids, alkalis, and salts. It is also called stainless acid-resistant steel. Stainless steel valves are also stainless acid-resistant steel valves. , And resistant to acid and alkali corrosion. Research tests have shown that the corrosion resistance of steel in weak media such as the atmosphere and water and oxidizing media such as nitric acid will increase with the increase of the chromium water content in the steel. When the chromium content reaches a certain percentage, the corrosion resistance of steel The sex changes, that is, from easy to rust to not easy to rust, from no corrosion resistance to corrosion resistance.
Common stainless steel valves mainly include stainless steel butterfly valves and stainless steel ball valves. The gate valve is rarely made of stainless steel, because the gate valve is usually used for low corrosive media such as water.
Stainless steel butterfly valve, also known as stainless steel flap valve, usually adopts three-eccentric metal hard sealing structure. The valve body, valve seat and butterfly plate sealing surface are all made of stainless steel with different hardness, which has strong corrosion resistance and long service life. It is widely used in metallurgical, electric power, petrochemical, water supply and drainage, municipal construction and other industrial pipelines with fluid pipeline medium temperature ≤ 425°C.
Stainless steel ball valves usually require horizontal installation in the pipeline. Stainless steel ball valves can be divided into stainless steel pneumatic ball valves, stainless steel electric ball valves, and stainless steel manual ball valves according to the driving mode. According to different stainless steel materials, it is divided into 304, 316, 321 stainless steel ball valves. The stainless steel ball valve switch is light and can also be made into a large diameter. It has reliable sealing, simple structure and convenient maintenance. The sealing surface and spherical surface are often in a closed state and are not easily eroded by the medium. It has applications in various industries.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:
Prevention and treatment of valve corrosion
The main classification and use conditions of valve sealing materials
How to achieve internal and external anti-corrosion of pneumatic valves
The difference and application of stainless steel 430, 304, 316

Problems Existing in the Use of Triple Eccentric Butterfly Valves

The triple eccentric metal seated butterfly valve is a high-quality valve category with high reliability and a wide range of applications. The triple eccentric butterfly valve is composed of main components such as valve body, butterfly

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

plate, valve stem, multi-layer metal sealing ring, shaft seal and drive mechanism. Its advantages are solid structure, good sealing performance, small torque, easy automatic control, etc. The triple eccentric butterfly valve is suitable for a variety of demanding working conditions, and has a wide range of applications in petroleum refining, natural gas extraction, chemical industry, power stations, metallurgy, and urban heating. However, things have two sides, and there are many problems in the use of the three-eccentric metal seated butterfly valve.
1. The butterfly plate of the triple eccentric butterfly valve is fixed with multiple layers of soft and hard stacked sealing rings. When the butterfly plate is in the open state, the circulating medium will directly wash the sealing surface. The soft sealing material in the metal sheet sandwich is in the long-term wash of the medium. It will directly affect the sealing performance of the valve.
2. The triple eccentric butterfly valve is not suitable for valves with a diameter smaller than DN200 because of its own structural constraints, the entire butterfly plate is very heavy and the flow resistance is very large.
3. The sealing between the butterfly plate sealing surface and the valve seat of the triple eccentric butterfly valve is to press the butterfly plate against the valve seat by the torque of the transmission device. When the medium in the pipeline is in a state of positive flow, the higher the pressure of the medium, the tighter the sealing and squeezing. But when the medium in the pipeline flows back, the pressure of the medium may cause seal leakage.
In order to solve the problems existing in the use of the triple eccentric butterfly valve, a high-performance triple eccentric two-way metal seated butterfly valve was developed. For the two-way sealing triple eccentric butterfly valve, the seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of the soft T-shaped sealing ring. The sealing surface of the butterfly plate and the valve seat is an oblique cone structure, and then a high temperature and corrosion resistant alloy material is surfacing on the sealing surface of the oblique cone structure, and the spring fixed between the pressure plate of the adjusting ring and the adjusting bolt of the pressure plate are assembled together .
This special structure effectively compensates for the elastic deformation between the shaft sleeve of the triple eccentric butterfly valve and the valve body, and perfectly solves the problem that the triple eccentric butterfly valve is prone to leakage during the two-way interchangeable medium delivery process. The soft T-shaped sealing ring composed of multilayer stainless steel sheets on both sides not only has the advantages of a metal seated material, but also has the characteristics of a soft sealing material. Therefore, the three-eccentric butterfly valve with two-way sealing is suitable for both low temperature and high temperature conditions. Under the conditions, it can maintain excellent sealing performance.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:
Selection and application of eccentric butterfly valve
The sealing characteristics and principle of eccentric butterfly valve
Electric ball valve-metal seated vs soft-seated type