The Advantages and Disadvantages of Floating Ball Valve

Why the ball valve is called floating ball valve? Because it has a floating ball. Except for the two sealing rings used for sealing, the ball is not supported by any other components and the ball seems to be in suspension.

What is the principle of floating ball valve? Because the floating ball is not restricted by any components, when the valve is closed, the medium presses on one end of valve(upstream), and the ball is displaced to the outlet of the valve ( On the sealing surface of the downstream).

The floating ball valve has many advantages , like small flow resistance, simple structure, good sealing performance, and being cost-effective for certain size and pressure. But it also has some disadvantages. The medium load on ball will be completely on the downstream sealing ring. At the same time, the gravity of ball itself will also be directly absorbed by the sealing ring. Therefore, for valve with too high pressure , or too big size, some problems will be caused.

1. When the valve diameter is the same, the higher the nominal pressure is, the greater the load of medium on ball is. When the nominal pressure of valve is the same, the larger the valve s, the greater the load of medium on ball is. Therefore, for valve of same diameter, when the nominal pressure is high enough,floating ball structure will be not suitable. For ball valve of same pressure, when the valve is too big size, it is also not applicable.

2. Because the gravity of ball itself will be directly on the seal ring, when the ball is too heavy, the weights will be severely uneven on different positions of  seal ring, which will result in irregular deformation of seal ring, and thus affects its service. Therefore, when valve is large enough, no matter how low the pressure is, the floating ball shouldn't be used.

3. the torque of ball valve is mainly deccided by the friction between ball and its seal ring.
There is a concept in the mechanical foundation: the friction between two objects (M) = positive pressure (F) * friction coefficient (f)
The coefficient of friction (f) is determined by the nature of the material itself, the material is selected, and the coefficient of friction is constant.The positive pressure (F) is proportional to the load (F1) of the working medium that the ball is subjected to.

From above, we can learn that when the load (F1) of  medium on ball is large, the friction between the ball and the sealing ring will be large, and the torque will also increase. Therefore, when valve diameter or nominal pressure is of the same, the high pressure or big size will greatly increase the torque of ball valve.

Pls refer to the following when choosing floating ball valve or trunnion mounted ball valve.

You can find more information on our web, so please take a look.

PN ≤ 2.5MPA (or 150lb), DN ≤ 200mm (or 8")
(DN≤200mm (or 8") is a defective product, preferably trunnion mounted ball valve)
PN=4.0MPA (or 300lb), DN≤150mm (or 6”)
DN ≤ 150mm (or 6") is a defective product, preferably trunnion mounted ball valve)
PN=10.0MPA (or 600lb), DN≤100mm (or 4”)
PN=16.0MPA (or 900lb), DN≤50mm (or 2”)
PN=25.0MPA (or 1500lb), DN≤40mm (or 1.5”)
PN=42.0MPA (or 2500lb), DN≤25mm (or 1”)

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3. How do Floating Ball Valves Work?

Floating ball valve uses a ball as the formation to prevent the flow of liquid and to shut the cross-section of the pipe.The main characteristic of a floating ball valve is, the ball has no definite structure to support it and it remains dangled in the fluid while the valve seats are static.

There are different standards available in floating ball valves some are, Design standard API 608, Test standard API 598, Fire Standard API 607, etc.

CATEGORIZATION:

Floating ball valve is categorized by,

One-piece floating ball valve:
One-piece floating ball valve and flange gate valve are the same type of valve but the difference exists in the closing part only. A sphere is used in one piece ball valve facilitating its rotation around the centerline of the body. The ball valve is mainly used to shut off, dispense and change the direction of the medium in the pipeline.

Two-piece floating ball valve:
Two-piece floating ball valve has two parts one is on the left and another is on the right, these two parts are connected by threads and bolts. This type of valve can withstand both high temperature and high-pressure conditions.

Link to Xiangyu

Three-piece floating ball valve:
In three-piece floating ball valve, the body is composed of three segments from left to right, one is the main body and the other two segments are bonnets; the ends are connected through threads and bolts like two-piece floating ball valve.

WORKING OF FLOATING BALL VALVE:

Floating ball valve has the ball inside the valve that is kept in the particular position by compressing two elastomeric supports towards the ball so that the ball can float inside the valve. To control the fluid, the ball is drooped in the flowing liquid by directing elastomeric seats.

At the top of the ball, the shaft is connected and allows the switch from open to closed position with a quarter-turn movement. When the shaft is moved, a load is applied to the ball which gets pressed against its seats. The ball floats and the seats are stable. This design is highly feasible and it suits bore sizes up to 10 inches. Floating ball valves allow a bi-directional shut-off to the flow. Valvualsfevisa being the ball valve supplier deliver reliable products, and they are known for being the best valve suppliers all over.

ADVANTAGES:

• Floating ball valve is simple in design, small in size and weigh less,
• Plastic is used for sealing purposes, which has a good sealing performance and is safe to use,
• It is easy to operate, fully open and closed position, at ease by remote control.

DISADVANTAGES:

• The sealing surface may suffer damage when roughly used,
• If the medium contains particles, then it is not suitable for those applications,
• Heavy sealing is needed for hard sealed valves.

CONCLUSION:

We, Fevisa being one of the leading Valve Manufacturers, ball valve suppliers, gate valve supplier, and more. We are popularly known as Valve Stockist and our valves with strict adherence to the International Standards like WRAS approved valves and UL FM approved valves. Our team of experts ensures that the essential mechanisms are of superior standards in order to work under the required extreme conditions. For more information on the related products visit our website and consult our team of experts at Fevisa, one of the leading suppliers of Stock valves and valve manufacturers worldwide.

If you are looking for more details, kindly visit Floating Ball Valve supplier.