Talking about the selection of the valve body material of the gas gate valve

Selection of valve body material for gas gate valve

According to the use pressure of the gas pipeline, the material of the valve shell is reasonably selected, which not only satisfies the safe operation of the pipeline, but also achieves the purpose of reducing the cost and making the best use of the material.

1. It is recommended to use gray cast iron valves for transmission and distribution pipelines below medium pressure level B (0.2MPa), which have the advantages of good corrosion resistance and low price, which is very suitable for underground pipelines;

Gas gate valve selection must meet these requirements

2. It is recommended to use nodular cast iron or cast steel for medium pressure class A (0.4MPa) or less, even high pressure class B (0.8MPa) or less, and nodular cast iron is recommended. For example: Comparing ductile iron grade QT400-18 with cast steel grade WCB, the former’s mechanical properties are no less than the latter, while the corrosion resistance and casting process are better than those of cast steel, and the price is also lower than that of cast steel (generally cast steel). About 70% of steel) Therefore, the overall performance and price of ductile iron valves are better than those of cast steel valves. Within the above-mentioned pressure range, ductile iron valves can be used, but special attention should be paid to the quality of ductile iron materials;

Z41H forged steel flange gate valve

     3. In places with high pressure class A (1.6MPa) or higher pressure levels, it is recommended to use cast steel valves. For valves with a pressure level below 4MPa, WCB grades are generally used;

     4. In recent years, gas companies in various places have begun to use PE pipes, and PE pipes are currently used under 0.4MPa pressure level.

     PE ball valves have also come out. This series of ball valves can be buried directly and has better sealing performance. However, the price of PE ball valves is relatively high, especially for ball valves with a diameter greater than 100mm. PE ball valves are currently in the promotion and trial stage.