What are the material of trunnion ball valve?

Trunnion mounted ball valve body material: WCB, WC6, WC9, CF8, CF8M, CF3, CF3M, etc. The trunnion mounted American standard ball valve usually uses rubber, nylon and Teflon as the seat seal material, so its use temperature is affected by the valve seat.

Because of limitation of seal material. In selecting the structure and performance of the industrial ball valve, it is necessary to consider the fire resistance and fire prevention of the ball valve, especially in the petroleum, chemical, metallurgical and other departments, the use of ball valves in flammable, explosive medium equipment and piping systems, more attention should be paid to fire resistance and fire prevention.

Here are the content list:

1. The following are the specifications for trunnion type ball valve material

2. The anti-corrosion of the trunnion mounted ball valve is mainly the correct selection of materials

3. Common materials 
   

A. The following are the specifications for trunnion type ball valve material

B. The anti-corrosion of the trunnion mounted ball valve is mainly the correct selection of materials. 

Although the anti-corrosion information is very rich, it is still not easy to choose the right one because the problem of corrosion is very complicated. For example, sulfuric acid is very corrosive to steel when the concentration is low, and steel is produced when the concentration is high. Passivation film can prevent corrosion; hydrogen only shows high corrosiveness to steel under high temperature and high pressure. 

Corrosion performance is not great when chlorine gas is in dry state, and corrosion performance is strong when there is certain humidity. Many materials cannot be used. The difficulty in choosing the industrial valve body material is that it can not only consider the corrosion problem, but also must consider the pressure and temperature resistance.

Metal hard seal ball valves can be used in a variety of media such as water, steam, oil, nitric acid, acetic acid and urea. At present, it has been widely used in chemical, petroleum, metallurgical and urban construction. Through the structurally optimized design, the metal hard seal ball valve can achieve frictionless and low torque opening and closing. The main failure mode of a metal hard seal ball valve in use is erosion wear. 

Although the service life and scratch resistance of metal hard seal ball valves can be improved by surface heat treatment or hardfacing of cemented carbide, it still cannot meet the requirements of special media such as steel ash, coal powder, silicon powder and alumina powder. . If the supersonic flame spraying technology is applied to the sphere, a carbide cermet coating can be formed on the surface of the sphere, and the coating can bond with the substrate up to 70 MPa, the porosity is less than 2%, and has a uniform and dense structure, which is relatively intact. Hard phase WC characteristics, hardness >1000HV wear and corrosion resistance, good mechanical properties, can significantly improve the performance of the ball valve.

Supersonic spraying this technology has obvious quality advantages over the traditional "plasma spraying". Its coating hardness and density are much higher than "plasma spraying"; "supersonic spraying" is different from the material used in "plasma spraying". Powder coating, the coating is granular, the density (G/CC- means water permeability) is high, easy to fall off, while the former uses expensive special materials, "the coating is block-like, the surface is extremely Fine, not easy to penetrate, shedding. 

C. Common materials 

such as: Ni-based alloy, CO-based alloy, tungsten carbide, various ceramics, high temperature oxidation resistant materials, high temperature insulation materials, various special functional materials, etc. 

High temperature resistance (450 degrees - 1200 degrees, special materials can withstand high temperature up to 1400 degrees), erosion resistance, corrosion resistance (salt corrosion, acid corrosion, alkali corrosion, hydrogen sulfide corrosion, etc.), high pressure resistance (70Mpa- 140Mpa). Bonding strength: 10000PSi pounds or more, finish: can be mirrored (within Ra0.2), porosity less than 1%, coating Vickers hardness up to HV1200 (Rockwell HRC70 Right), ceramic (bar) Vickers hardness about HV1900 (about Rockwell HRC80).