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 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 titanium has very active chemical properties and easily reacts with oxygen in the air to form a dense oxide film on the surface. This oxide film is very stable and difficult to dissolve. Even if it is damaged, it can repair itself and regenerate an oxide film as long as there is sufficient oxygen. It can resist the erosion of various corrosive media and solve the corrosion problems that are difficult to solve for stainless steel, copper or aluminum valves.
Titanium and titanium alloy valves (hereinafter referred to as titanium valves) have the following main characteristics:
• Titanium valves are not only corrosion-resistant, but also light in weight and have high mechanical strength.
• Titanium valves are almost not corroded in the atmosphere, fresh water, sea water, and high-temperature water vapor.
• Titanium valves have good corrosion resistance in media such as aqua regia, chlorine water, hypochlorous acid, and wet chlorine gas.
• Titanium valves are also very corrosion-resistant in alkaline media.
• Titanium valves are very resistant to chloride ions (CI) and have excellent chloride ion corrosion resistance.
• The corrosion resistance of titanium valves in organic acids depends on the reducing or oxidizing properties of the acid.
• The corrosion resistance of titanium valves in reducing acids depends on whether the medium has a corrosion inhibitor.
