Features and applications of titanium valves
Titanium is an important structural metal. Compared with other metal materials, titanium has two significant characteristics: high specific strength and good corrosion resistance. The main consideration for valve materials is not the mechanical properties of the material, but the corrosion resistance, so titanium and titanium alloys have become one of the indispensable valve materials.
The reason why titanium has excellent corrosion resistance is that its chemical properties are very active and easily react with oxygen in the air to form a dense oxide film on the surface. This layer of oxide film is very stable and difficult to dissolve. Even if it is damaged, as long as there is enough oxygen, it can repair itself and regenerate the oxide film. It can resist the corrosion of various corrosive media, and solve the corrosion problem of stainless steel, copper or aluminum valves.
Titanium valves mainly use titanium metal materials to have good stability and self-passivation ability in the oxide film in a strong corrosive environment. This feature can resist a variety of harsh working conditions and strong corrosion.
Whether the titanium valve can resist the corrosion of the working environment, the key lies in the chemical stability of the “passive oxide film” on the surface in the corrosive medium. For neutral, oxidizing, and weakly reducing media environment, the “passive oxide film” itself has good stability. For reducing corrosive media with high temperature or low PH value, in order to improve the stability of its “passive oxide film”, corrosion inhibitors (such as air, water, heavy metal ions and anions, etc.) can be added, such as titanium surface ion modification To improve the corrosion resistance and surface hardness of “titanium” in reducing media to meet the requirements of use.
Titanium and titanium alloy valves (hereinafter referred to as titanium valves) mainly have the following characteristics:
- Titanium valve not only has good corrosion resistance, but also has light weight and high mechanical strength.
- The titanium valve hardly corrodes in the atmosphere, fresh water, sea water and high temperature water vapor.
- Titanium valves have good corrosion resistance in aqua regia, chlorine water, hypochlorous acid, wet chlorine and other media.
- Titanium valves are also very resistant to corrosion in alkaline media.
- The titanium valve has a very strong anti-chloride ion (CI) ability and has excellent anti-chloride ion corrosion resistance.
- The corrosion resistance of titanium valves in organic acids depends on the reduction or oxidation of the acid.
- The corrosion resistance of titanium valves in reducing acids depends on whether the medium has corrosion inhibitors.
Application of titanium valve
The high specific strength and corrosion resistance of titanium and titanium alloys provide a vast space for its application in the aerospace field. Only in terms of valve types, titanium valves are widely used in various pipelines on aircraft. Involving regulating valves, globe valves, check valves, needle valves, plug valves, ball valves, butterfly valves, etc., pure titanium and titanium alloy Ti-6Al-4V are more common for the titanium used in valves.
2. Chemical industry
In chlor-alkali projects, salt industry, synthetic ammonia projects, ethylene projects, nitric acid projects, acetic acid projects and other projects involving strong corrosive media and environments, the corrosion resistance of common metals such as stainless steel, copper, aluminum, etc. is difficult to meet the requirements for use, and must be used For titanium alloys with better corrosion resistance, a large number of titanium valves must be used in the control and adjustment parts of the medium conveying pipeline.
3. Ship field
Russia is one of the first countries in the world to develop titanium alloys for ships and has the most in-depth research. In the 1960s and 1980s, Russia produced a series of attack submarines, including the “Alpha” class with a titanium alloy usage of 3000t A large number of titanium alloy pipelines and titanium alloy valves are used in the seawater system of submarines and “Typhoon” class submarines that use 9,000 tons of titanium.
4. Nuclear power field
As nuclear power plants are built along the coast, titanium valves are used in nuclear power projects due to their excellent seawater corrosion resistance. The types include safety valves, pressure reducing valves, globe valves, diaphragm valves, ball valves, etc.
In addition, as a fluid control necessity under special media and environments, titanium valves are also widely used in the paper industry, food and pharmaceutical manufacturing and other fields, and the future market is very broad.
Source: China Titanium Valve Provider: www.titaniuminfogroup.com