The floating ball is floating. Under the action of medium pressure, the ball can produce a certain displacement. The pressure on the outlet end of the seal ring to ensure that the outlet end. The seal is a single-side forced seal.
The fixed ball valve ball is fixed. After the compression does not move, therefore, the design of the two sealing rings should be sufficient preload to ensure that the seal is a double-sided forced seal. Thrust or sliding bearings are usually provided on the upper and lower stems connected with the ball.
The design of floating ball valves should be focused on considering whether the sealing ring material can withstand the ball of the medium load. Because the ball bears the load of the working medium all to the outlet seal ring. Therefore, the floating ball structure is widely used in low and medium-pressure ball valves. In addition, the floating ball valve ball is floating. Under the action of medium pressure, the ball can produce a certain displacement and pressure on the outlet end of the seal ring. The outlet end of the seal is a one-way forced seal.
The main characteristics of the ball valve
The valve has a compact structure, reliable sealing, a simple structure, and convenient maintenance. The sealing surface and spherical surface are always in a closed state. It is not easy to be washed with the medium. It is easy to operate and maintain. It is suitable for water, solvent, acid and natural gas and other general working media. It is also suitable for bad working conditions of the medium, such as oxygen, hydrogen peroxide, methane and ethylene, etc. It has been widely used in various industries. The ball valve body can be integral or combined.
The product features of fixed ball valves
1. Reliable sealing performance: PTFE simple material sealing ring is embedded in the stainless steel seat. The metal seat end is provided with a spring to ensure sufficient pre-tightening of the seal ring. The sealing surface wear in the use of valves, the valve continues to ensure good sealing performance under the action of the spring valve.
2. Operation labor-saving: the ball is supported by upper and lower bearings. It can reduce friction and eliminate the huge sealing load in excessive torque caused by the ball driven by the inlet pressure and the sealing seat.
3. Fireproof structure: the occurrence of sudden heat or fire can make the PTFE sealing ring burn to produce large leakage, and fuel the fire, therefore, the fire sealing ring is set between the ball and the seat. When the sealing ring is burned, the seat sealing ring quickly pushes to the ball under the action of the spring force. The metal and metal seal form. It plays a certain degree of sealing effect. The fire resistance test meets the requirements of APl 6FA and APl 607 standards.
4. Automatic pressure relief function: when the stagnant medium pressure in the valve cavity rises abnormally and exceeds the pre-force of the spring, the valve seat recedes from the ball to achieve the effect of automatic pressure relief. The valve seat automatically recovers after pressure relief.
5. Discharge pipeline: the valve body is set up above and below the discharge hole. It can check whether the valve seat is leakage. In the work, the valve is fully open or fully closed. Remove the pressure of the cavity and it can directly replace the packing. It can discharge the cavity retention and reduce the medium to the valve pollution. The fixed ball valve is widely used in food, medicine, petroleum, chemical, natural gas, steel, environmental protection, paper and other cut-off or flow of transmission pipeline mediums. The device can also be injected with the corresponding cleaning agent or lubricant to clean the sealing surface.
The design of the floating ball valve should be focused on considering whether the sealing ring material can withstand the ball of the medium load. Because the ball bears the load of the working medium all to the outlet seal ring. Therefore, the floating ball structure is widely used in low and medium-pressure ball valves. In addition, the design should also consider that the large-diameter ball valve operation needs large torque.
