Ball Valves         

General:

Ball Valves are the most common Valve within the Oil & Gas business.

Function:

The main function of a Ball Valve is sealing of the flow. A Ball Valve should not be used for throttling (semi open / closed position). This will cause damage the ball due to erosion on the ball it selves.

Operation:

  • Ball Valves are probably the type of Valve with the highest failure rate of all Valves. Some Ball Valves might be destroyed after only one single operation, while others might last for many years, it’s all dependent on how the Ball Valve is treated, and the amount and quality of maintenance carried out.

Design:

  • A Ball Valve body could be assembled from typical two or three main parts sealed and bolted together, or alternatively welded together to increase the safety of the Ball Valve, especially used in the pipeline industry. There are a lot of different ball valve designs; however the basic principle is the same for all of them.
    The Ball Valve consists of a highly polished ball place within the body of the valve. The ball is either floating or trunnion mounted. A floating ball has only one support from the top of the ball, and it is free to move against the downstream seat while the pressure is rising.
    The higher pressure the tighter valve is the basic principle of a Ball Valve with floating ball. A new Floating Ball Valve will seal off both on the upstream and downstream seat.
    On a trunnion Ball Valve the ball has support on both top and bottom, and the ball will not move under pressure. A trunnion Ball Valve has springs pushing the seats against the ball both up and downstream