What are the differences between valves in different media?

The material of the valve must meet the requirements of the operating conditions, such as pressure rating and the corrosiveness of the medium. In factories, there is not much difference between gases and liquids (with the exception of oxygen pipelines). Just check the valve manual; the applicable conditions are listed there.

It’s mainly because the sealing materials are different. Those components come into contact with the medium, so they certainly vary. Gases and liquids require valves that are suitable for their respective uses

There are many differences; even when the material and pressure drop are the same, the methods of multi-stage pressure reduction for liquids and gases also vary.

Check the corresponding valve manual to see if the material and pressure drop are the same, and whether the methods for reducing pressure in liquids and gases are identical

This depends on the medium and the characteristics of the process. Just assign this task to a valve company, and it will be solved!

Selection of materials for control valves: (1) The pressure rating, operating temperature, and corrosion resistance of the valve body should meet or exceed the requirements of the process connection pipes, and preferrably, products that are standardized by the manufacturer should be chosen. (2) Cast iron valves are not suitable for water vapor or wet gases with high moisture content, as well as flammable and explosive substances. (3) When the ambient temperature is below –20°C (especially in the north), cast iron valves are not suitable. (4) In the rectangular coordinate system defined by medium temperature and pressure difference, where cavitation and erosion are severe, areas outside the line connecting the points of 300°C temperature and 1.5 MPa pressure difference require the use of wear-resistant materials for the throttle sealing surfaces, such as cobalt-based alloys or Stellite alloys deposited on the surface. (5) For highly corrosive media, the selection of corrosion-resistant alloys requires choosing appropriate materials based on factors such as the type, concentration, temperature, and pressure of the medium. (6) The valve body and the throttling element are treated separately; the inner wall of the valve body experiences a low throttling velocity and can tolerate a certain degree of corrosion, with an erosion rate of around 1 mm per year ； The throttle element is subject to high-speed erosion and corrosion, which can lead to increased leakage; its corrosion rate should be less than 0.1 mm per year. (7) When selecting the lining material (rubber, plastic), the temperature, pressure, and concentration of the working medium must all fall within the range suitable for that material; At the same time, consideration must be given to the physical and mechanical damage that may occur to it during valve operation (such as shear failure). (8) Vacuum valves should not employ a valve body lining with rubber or plastic structures. (9) Rubber-lined materials should not be used for the two-position shut-off valves in water treatment systems. (10) Selection of typical corrosion-resistant alloy materials for typical media: a. Sulfuric acid: 316L, Hastelloy, Alloy 20. c. Hydrochloric acid: Hasselblad B. d. Hydrofluoric acid: Monel. b. Nitric acid: aluminum, C4 steel, C6 steel. e. Acetic acid, formic acid: 316L, Hastelloy. f. Phosphoric acid: for nickel alloys and Hastelloy. g. Urea: 316L. h. Caustic soda: Monel. i. Chlorine: Hastelloy C. j. Seawater: Inconel, 316L. (11) To date, the most versatile corrosion-resistant material is tetrafluoro, known as the \"king of corrosion resistance\". Therefore, fully fluorinated corrosion-resistant valves (patented products from Hualin Institute) should be chosen first; alloys should only be used as a last resort (e.g., when the temperature is >180°C and PN > 1.6).

There are many factors to consider when selecting valves; it’s clear enough that this applies whether the medium is a gas or a liquid, but many other operating conditions also need to be taken into account, such as temperature/pressure/whether particles are present/use location, and so on. . . .