It is hard to imagine any setting of a plant that has no valve, especially those handling gas, oil, and petrochemical industries. Choosing between a ball valve, and a gate valve might be confusing, since they seem to perform the same function.
If you want to make a choice between the two, you should first start by understanding how they function:
Ball valve
It is known as a ball valve because it has a stem and a ball that has a hole. The ball turns horizontally allowing the product to follow, and once it turns to be perpendicular, the product is closed from flowing.
Gate valves
The gate valves have a rectangular/round gate which can be lifted up to allow the product to flow in the application. The raising, and lowering of the gate is done by the operators using a knob.
Now that you know how they function you should get to know their attributes, and some of the attributes that sets them apart include:
Shut off capabilities
The ball valves allow instant shut off, since they only move to a maximum of 90 degrees, so they are ideal for operations that require immediate cut off of flow, and instant opening.
With the gate valve you cannot shut off immediately, but is ideal in applications where the operator needs to control the amount of product flowing. For applications that require immediate shut off you should use the ball valve, but if you require a high degree of control use the gate valve.
Longevity
Ball valves stay for long, and in applications that require frequent operations, it is crucial that you have a rising stem ball valve, because it can stay long. It can function even when it has not been used for a long time.
On the other hand, the gate valves tend to be prone to corrosion, and once you stay for a long time without opening it, it becomes worthless, and you will have to change it.
Sealing properties
The other special property of the ball valve is that it can guarantee that there is no leakage. It seals the product, and prevents it from flowing completely.
If there is high pressure, the gate valve will allow some of the product to leak, and in most cases the product can escape via the handle.
Prices
Due to the numerous wonderful features of the ball valve, it is more expensive than the gate valve.
Choosing the right valve
When you now choose the valve to use for the particular application, you should look at what you need, and also consider whether you can afford to buy the valve. The two valves are valves you can use, and I would recommend that you buy the ball valve unless it is somewhere you need high control of the product, since it lasts long, and way more durable.
Bottom Line
Choosing between a gate valve, and a ball valve might be confusing, but once you understand how they operate it is easier. Choose a valve that will help you operate efficiently.