Sealing grade of valves in Class A area

1, main seal. It is suitable for occasions with strict leakage requirements, such as flammable and explosive media such as gas and natural gas. The primary seal usually adopts double seal structure to ensure the reliability of the seal.

2. Secondary sealing. Suitable for occasions with high leakage requirements, such as liquefied petroleum gas and chemical media. Secondary sealing usually adopts a single sealing structure, such as sealing ring and gasket.

3. Three-level seal. Suitable for general leakage requirements, such as water, steam and other media. Three-stage sealing usually adopts simple sealing structure, such as sealing surface and sealing line.