Distinguish from the structure of piece ball valve：
One-piece ball valve is a one-piece inside by the ball, teflon ring, lock nut composition, the ball diameter is slightly smaller than the pipe diameter, similar to the wide ball valve.
Two-piece ball valve is composed of two parts, the sealing effect is better than one-piece ball valve, the ball diameter and pipeline diameter of the same, easier to remove than one-piece ball valve.
Three-piece ball valve is composed of three parts, on both sides of the valve cover and the middle valve body, three-piece ball valve is different from the two-piece ball valve and one-piece ball valve is easy to remove maintenance.
Distinguish from the pressure of ball valve：
Three - piece pressure is much higher than one - piece and two - piece ball valve.The main three - piece ball valve outside by four bolts fixed, a good tightening effect.The pressure of the precision cast body can reach 1000psi 6.9MPa. Forged body for higher pressure.
Distinguish from the structure of ball valve：
1. Floating ball ball valve: the ball of the ball valve is floating. Under the action of medium pressure, the ball can produce certain displacement and be pressed tightly on the sealing surface of the outlet end to ensure the sealing of the outlet end. The structure of the floating ball ball valve is simple, good sealing, but the ball bears the load of the working medium all passed to the outlet sealing ring, so it should be considered whether the sealing ring material can withstand the working load of the ball medium. This design is widely used in low and medium pressure ball valves.
2. Trunnion ball valve: ball valve ball is fixed, the pressure does not produce movement. Trunnion ball valve with floating seat, by the medium pressure, the seat seat to produce a movement, so that the sealing ring pressed on the ball, to ensure that the seal. Bearings are usually mounted on the upper and lower shafts of the ball, with small operating torque, suitable for high pressure and large diameter valves. In order to reduce the operating torque of the ball valve and increase the reliability of the seal, the appearance of the oil seal ball valve, the sealing surface between the pressure injection of special lubricating oil, in order to form a layer of oil film, that is to enhance the sealing, and reduce the operating torque, more suitable for high pressure large diameter ball valve.