Ball valve uses the ball with a circular passage as a hoist part,
the ball is rotated with the stem to achieve open and close action.
Its hoist part is a hole ball, rotated around the axis that is
perpendicular to the channel, so as to achieve open and close
channel purpose. According to structural forms, it can be divided
into: floating, fixed, flexible type and grease seal-type;
according to channel, it can be divided into: straight-through,
corner type and three-way type, etc.
Three-way type can also be divided into T-shaped and L-shaped;
according to connections, it can be divided into: screw-type
connection, flange connection and welding connection.