Difference Between A Vented Ball Valve And A Standard Ball Valve

Difference Between A Vented Ball Valve And A Standard Ball Valve

Judging by what makes up the individual functions of these two valves, the difference between a vented ball valve and a standard ball valve is quite simple and obvious. However, the difference between these valves becomes more critical when we consider the aspect of cryogenic processing.

Based on the application of ball valves for cryogenic processing, surface level distinctions between these valves becomes less important. Now, it is important to know beyond the simple differences and focus on understanding why they are different.

Let’s take a look at why a vented ball valve is used for cryogenics and the advantages of using it for this purpose.

Standard Ball Valve Vs. Vented Ball Valve

The most significant way in which the vented ball valve (commonly called a cryogenic valve) differs from a standard ball valves is that a hole is drilled into the upstream side of the vented ball valve. Generally, the standard ball valve consists of a housing, a ball with a bore that allows the flow of materials, a stem that controls the ball position and seals that the ball rests between, but does not have a visible hole in the ball when the valve is in a closed position. Apart from this (looking at the surface level at least), there would be no significant difference between the two valves in how they look and operate. When the ball is turned one way, the bore of the ball allows upstream flow – where the flow of materials from one end (inlet) of the valve to another (outlet) is permitted. When turned the other way, the flow of material is totally halted.

The design of the standard ball valve is quite simple yet ingenious and this makes it suitable for a numerous count of applications involving different materials. When the standard ball valve is closed, the ball forms a snug seal. Hence, it is ideal for water and other similar fluid applications. But when it comes to cryogenic processing, the ball valve is not suitable as it can cause leaking or valve failure. More importantly, in the event that a natural process occurs in which the cryogenic process heats up, turns into a gas and expands inside the valve, the standard ball valve could explode. This unwanted pressure inside the valve is easily eliminated by the vented ball valve as it disperses the pressure through the vent on the ball.

Now that we know how pressure builds up during cryogenic processing,it’ll become easier to understand the major difference between these ball valves. Vented ball valves can eliminate the problem of pressure build during cryogenic processing, while, the standard ball valve cannot.

Conclusion

Without considering the cryogenic processing, the vented ball valve and the standard ball valve both look and function in the same way. However, this single difference between them is a very crucial and significant factor that cannot be overlooked. Knowing this difference make it easier to answer the question “why do you need a vented ball valve?”