The structure of the eccentric hemisphere valve adopts the eccentricity-tightening principle to achieve the purpose of brake tightening, adjustment and closing through the transmission mechanism. The sealing pair is a metal surface ring with a hard surface contact seal. The cross section is large and the valve is not flushed. When closed, the valve core is not flushed. The spherical surface of the valve core is opened gradually along the valve seat, which effectively removes the fouling obstacle and achieves a reliable seal. It is particularly effective for mixed-flow conveyance of two-phase mixed-flow solid-scale deposits. The second feature is the use of bimetals in the hemisphere of the valve. The base material is superimposed with different alloys. The valve seat is also superimposed with special treatment. The sealing surface is combined into various types such as anti-corrosion, abrasion resistance and high strength to meet different requirements. Occasionally required, the third feature is that sealing is strictly prohibited, and the transmission of harmful gases can reach zero leakage. The fourth feature is that the valve core of the sealing pair has a compensation amount. When the valve seat is worn (the valve seat hardness is lower than the valve core), it is closed. If you turn it a little more, it can still seal reliably and prolong the service life. In addition, the user can unscrew the compression nut, and the valve seat can still be used after adjustment or replacement, which avoids the disadvantages of many existing valve seal failures and the entire scrap.
Therefore, the option of surfacing welding different alloy (or combination ball) bimetal sealing pairs can be used in different industrial sectors that require wear resistance, corrosion resistance, temperature resistance, etc., and require strict sealing.
The main uses and product features of ball valves:
1. General purpose valve: Specification model PN1.0-4.0Mpa, DN40-1600. It is suitable for places with strict requirements such as sewage treatment, pulp, urban heating and heating.
2. Special valve for oil and chemical industry: Specification DN40-1600, PN1.0-4.0Mpa is suitable for various oil products such as crude oil and heavy oil, weakly corrosive and two-phase mixed flow medium in chemical industry. The temperature can reach 425 ℃.
3. Special gas valve: Specification DN40-1600, PN1.0-4.0Mpa is suitable for gas, natural gas and liquefied gas transportation control. The product structure is characterized by sealing and overlaying different chromium-containing stainless steels, tight sealing and corrosion resistance.
4. Slurry special valve: Specification DN40-1600, suitable for industrial pipeline transportation with crystal precipitation or fouling during chemical reaction in liquid and solid two-phase mixed flow or liquid transportation. Product structure characteristics According to customers' requirements for different media and temperature requirements, chrome-molybdenum-vanadium alloys are used for surfacing of the valve core of the sealing vice, and chrome-molybdenum alloys, chromium alloys, and stainless steel alloy electrodes are used for surfacing to meet the needs of different slurry transportation.
5. Special valve for pulverized coal ash and slag: Specification DN40-1600, suitable for control of power plants, hydraulic slag removal or gaseous pipelines. The product requires wear resistance. The valve core uses a combination ball type bimetal, which has a very high rigidity and is very wear-resistant.
Ball valve product features:
1. Large circulation area and small flow resistance. This is because the valve core is located in the Tibetan ball chamber after opening, and the fluid flows through.
2. The operating torque is small, and the opening and closing can be completed by turning 90 degrees, and the operation is light.
3. Tight seal, double eccentric metal hard seal. Fouling does not affect the opening and closing, which is the most significant advantage of the hemisphere valve
4. Long service life, wear-resistant sealing pair, and compensation amount, valve seat can be adjusted or replaced.
Parts materials and working conditions:
|Valve body||QT450, WCB, ZG20CrMo, ZG1Cr18Ni9Ti|
|Valve shaft||2Cr13, 1Cr13|
|Disc||Alloy nitriding steel, nitriding stainless steel, wear-resistant steel|
|Valve seat||Alloy nitriding steel, nitriding stainless steel, wear-resistant steel|
|Bearing||Aluminum bronze, FZ-1 composite material|
|filler||PTFE, flexible graphite|
Main performance parameters:
|Nominal pressure (Mpa)||0.6||1.0||1.6||2.5||4.0|
|Nominal diameter (mm)||40-1600||40-1600||40-1200||40-600||40-600|
|Sealing test pressure (Mpa)||0.66||1.1||1.76||2.75||4.4|
|Shell test pressure (Mpa)||0.9||1.5||2.4||3.75||6.0|
|Applicable temperature (℃)||-29 to 300, -29 to 425, and -29 to 540|
|Applicable medium||Clear water, sea water, sewage, acid and alkali liquids, slurry, steam, gas, oil|
|Drive way||Manual, electric, pneumatic|
|Connection Type||Flange connection, Wafer connection|
|Installation method||Vertical installation, horizontal installation|
Shape and connection size
|Nominal diameter mm||L||D||D1||D2||N-φ||b||f|