Description

What is floating ball valve

The ball of the floating ball valve is floating. Under the action of the medium pressure, the ball can produce a certain displacement and press tightly on the sealing surface of the outlet end to ensure the sealing of the outlet end.
The floating ball valve has a simple structure and good sealing performance, but the load of the ball bearing the working medium is all transferred to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium, the sphere may be offset. This structure is generally used for medium and low pressure ball valves.
The main features of the ball valve are its compact structure, reliable sealing, simple structure and convenient maintenance. It is also suitable for medium with harsh working conditions, such as oxygen, hydrogen peroxide, methane and ethylene, etc., and is widely used in various industries. The ball valve body can be integral or combined.

What is the difference between floating and trunnion ball valve?

1. The floating ball valve and the trunnion ball valve are still easy to distinguish in appearance. The floating ball valve is a ball valve without a trunnion, and the trunnion ball valve is a ball valve with a trunnion.
2. Floating ball valve is suitable for low and medium pressure, and the diameter is small, trunnion ball valve can withstand up to 2500 LB, and the size can reach 60 inches
3. The trunnion ball valve can realize the function of double resistance and double row, while the floating ball valve is mostly one-way seal. The trunnion ball valve can block the medium at both ends of the upstream and downstream at the same time. When the pressure in the cavity of the valve body is greater than the tightening force of the spring of the valve seat, the valve seat will be pushed open to release the pressure in the cavity to ensure safety.
4. The working life of trunnion ball valves usually are longer than floating ball valves
5. Trunnion ball valves have less torque than floating ball valves, so it’s more easy to operation.
6. Trunnion ball valves above 4 inches are equipped with seat grease injection valves, floating ball valves without it
7. The sealing performance of the trunnion ball valve is more reliable than floating ball valve

How does a casting floating ball valve work?

Casting floating ball valves are operated by a shaft or stem attached to the top of the ball, which rotates the ball 90 degrees (a quarter of a turn). As the ball rotates, the ports are covered or exposed by the walls of the valve body, releasing or stopping the flow of media. The connection between the stem and ball is loose enough that when the ball rotates around its axis, fluid pressure pushes the ball against the downstream seat, creating a tight seal. For this reason, floating ball valves may not seal effectively in very low pressure applications after a certain amount of seat wear. This is because there may not be enough media pressure to force the ball against the downstream seat to form a tight seal. In most applications, however, the downstream pressure is sufficient to maintain a tight seal long after the seat begins to wear.