What are the differences between Gate valves & Ball valves?

When it comes to piping valves, there are many options available with different size and shape for you to choose. But in term of popularity, Gate valve and Ball valve are among the most commonly used valve type due to their excellent performance. Nonetheless, these valves have unique characteristics so you should not use them without proper consideration and planning before hand.

Gate valves vs. Ball valves, it’s not easy to tell which one is the better choice, especially if you know little about them. In the case you wish to learn more about the valves and the way they work, you come to right place. Here is a comprehensive analysis of these valves along with their advantages and disadvantages in different applications.

Gate valves：What is a gate valve?

The gate valve earns its name from its internal mechanism which includes a round or rectangular wedge that serves as a stream gate. By moving the wedge up and down through an external handle, you would be able to control the liquid stream.

In the usual case, the gate valve is used to start/stop the liquid flow, it’s rarely used for stream regulating. A gate valve tends to have two ports, an outlet and an inlet. Many gate valves utilize threaded ports but flanged and soldered designs are also available.

The valve application:

Due to its ability to slice through the liquid with ease, the gate valve is widely employed in the petroleum business. Household arrangements also utilize gate valves as well and the valve popularity in the area is increasing steadily. Typical gate valves are designed to be closed or opened completely so as to reduce potential friction loss.

The valve style:

• Brass Gate Valves: If corrosion is a serious problem, this is the valve you should use. It’s also able to endure high temperature so the valve is often used in manufacturing applications.

• Stainless Steel Gate Valves: Thanks to its rust free and corrosion resistant material, the valve is a good choice when corrosion reaches an epidemic level. Since stainless steel would not leach into the water, you don’t have to worry too much about metal contamination and alike. As a result, it’s could withstand weather element, human error as well as tree roots.

Advantages and disadvantages:

One notable strong point of the gate valve is that it would not cause a water hammer due to the valve slow mechanism. If you don’t know, water hammer is a pressure surge caused when the liquid stream is suddenly forced to stop. Water hammer could lead to major problems such as excessive vibration and noise or even a total pipe collapse.

However, gate valves also have a couple of drawbacks relate to its screw handle mechanism. When the valve mechanism is corroded, the valve would no longer work properly. On several valve models, the wedge could get stuck in the partially closed or partially open position which could accelerate the wearing rate.

Compare with other valves:

Butterfly valve vs. Gate valve

Butterfly valves are lighter and more compact than gate valves which make them are a good choice for cramped applications. However, butterfly valves are unable to handle corrosion, inflammable and hazardous materials. They mostly used for low temperature and low-pressure arrangement.

Plug valve vs. Gate valve

Plug valves are ideal choices when it comes to quick shutoff and generally economical to operate. Nonetheless, because of the high friction, it’s only employed for precise throttling/modulating.

Globe valve vs. Gate valve

In contrast with gate valves, globe valves are usually designed to regulate the flow rate of the stream. Due to its construction, the glove valve is less vulnerable to seat leakage compared to other valves. You cannot set the valve in any directional flow through.

Stop valve vs. Gate valve

For most of the time, stop valves are often used for household fixtures such as toilets and sinks. They utilize a rubber gasket to shut off the water flow which is not as reliable and efficient as the gate valve wedge.

Ball valves：What is a ball valve?

As the name suggests, ball valves utilize a compact sphere to shutoff the flow of liquid. The sphere itself has a hole, aligning the hole with the pipe would allow the stream to move freely through it. On the other hand, when the hole is perpendicular to the pipe, the flow is stopped entirely.

You could control the ball position through a lever on top. Usually, moving the lever at 90-degree angle would permit stream to pass through or cut it off. The lever is designed in a way that you cannot rotate it more than 90 degrees. In the usual case, the ball is placed on a valve seat with the stern inserted on top of it.

The valve application:

Thanks to its robustness and simplicity, the ball valve is used in many applications such as petroleum, household, marine, pharmaceuticals as well as heavy industry. Since it could be designed so the lever rotation is approximately proportional to the flow rate, the valve is able to prove active stream regulation. That is why it’s widely used in a variety of application.

The valve style:

• Brass Ball Valves: This valve type handles heat pretty well so it’s commonly used for high-temperature applications.

• Bronze Ball Valves: Mainly found on ships because the valve is able to endure constant exposure to seawater.

• Stainless Steel Ball Valves: Well appreciated for their strength and overall resistances, these valves are what you need when it comes to chemical and water applications.

Advantages and disadvantages:

Ball valves are simple to activate and deactivate so they could be operated by someone who could not manipulate a wheel type valve.  Moreover, you are able to tell the valve position at a glance. In most of the case, ball valves possess high endurance, excellent versatility and long lifespan. They would work reliably for years to come without running into any troubles.

However, the ball valve does have some shortcomings such its requirement for space. Several applications may not have enough room for you to rotate the handle which somewhat limits the use of ball valve. The ball valve could occasionally cause a water hammer situation as well.

Compare with other valves:

Globe valve vs. Ball valve

For shutoff applications, people prefer to use ball valves but globe valves are superior at regulating the flow rate. If you want to have excellent throttling control, you should consider using globe valves.

Plug valve vs. Ball valve

In general, the ball valve could offer you a certain degree of throttling control which is much better than the plug valves. In addition, ball valves could function well for years while plug valves may get stuck eventually and therefore become difficult to operate. Beyond that, these valves are quite similar and even interchangeable in some cases.

Butterfly valve vs. Ball valve

When it comes to endurance, ball valves are capable of handling moderate pressure and temperature floatation. In contrast, butterfly valves could only be used in low pressure and low-temperature applications.

Conclusion:

And that is most of what you should know about these valves, not too hard to absorb, right? Gate valves vs. Ball valves, it’s not easy to decide the winner without taking into account your needs and requirements. But with the help of this article, you should be able to decide the right valve type to use for your piping system.