Sealing Types of Ball Valves
Soft seal—in the inlet and outlet of the floating ball valve, implant the valve seat separately as symmetrical as possible. Seat provides initial preload by its own elasticity. This construction is reliable and easy for sealing. The common sealing material is Nylon, RPTFE, PPL, PTFE, PEEK, etc.
Metallic hard seal—consists of valve seat, sealing ring and gasket in the inlet of ball valve, surfacing hard metal on sealing ring and fixing the sealing ring on the seat by gasket. Seats and bodies are sealed through O-rings to provide the necessary initial seal preload for valves. While in the outlet of the ball valve, usually it's directly surfaced with hard metal to not only prevent valve body from seat damage, but also from the damage of sticky media and solid particles. Satellite is always selected as hard metal.
Installation direction is required in such valves. Metallic hard seal ball valves are applicable for high pressure, high temperature and viscous and unclean slurry.
Composite seal—This is combination of soft seal and metallic hard seal. Hard seal is primary seal, most of the media particulate impurities are cut by the hard metal to stop entry into the secondary seal, which is soft seal, and can completely block the media. There's no installation direction required for such valves.
This type of valve seal owns advantages of both soft seal and hard seal, with better corrosion resistance, easy cooperation and long service life.
Metallic hard seal—consists of valve seat, sealing ring and gasket in the inlet of ball valve, surfacing hard metal on sealing ring and fixing the sealing ring on the seat by gasket. Seats and bodies are sealed through O-rings to provide the necessary initial seal preload for valves. While in the outlet of the ball valve, usually it's directly surfaced with hard metal to not only prevent valve body from seat damage, but also from the damage of sticky media and solid particles. Satellite is always selected as hard metal.
Installation direction is required in such valves. Metallic hard seal ball valves are applicable for high pressure, high temperature and viscous and unclean slurry.
Composite seal—This is combination of soft seal and metallic hard seal. Hard seal is primary seal, most of the media particulate impurities are cut by the hard metal to stop entry into the secondary seal, which is soft seal, and can completely block the media. There's no installation direction required for such valves.
This type of valve seal owns advantages of both soft seal and hard seal, with better corrosion resistance, easy cooperation and long service life.
