There are four types of gas commonly used in China: natural gas, liquefied gas, artificial gas and the mixture of liquefied gas and air. Natural gas is the least corrosive, followed by liquefied gas, and artificial gas is the most corrosive. The harmful substances in artificial gas are mainly sulfur dioxide, naphthalene, coal tar, etc.

The materials of valves for natural gas can have no special requirements. If ordinary carbon steel is used, surface treatment must be done to prevent corrosion. However, it is better not to use ordinary copper material on the valve for artificial gas. It will become copper sulfate after meeting with sulfur dioxide in water, which will cause great corrosion to the parts. To be clear; The artificial gas is very easy to form naphthalene on the valve and pipeline, which is a white crystal, very hard and difficult to remove, affecting the closing and opening of the valve. Coal tar is sticky everywhere in valves and pipes, which is very difficult to clean. At present, there is no good solution.