Gate valves are also known as slide valves or knife valves. A gate valve consists of a flat closure piece that slides into place. The inside diameter of the valve body is often very close or identical to attached pipes, so a fully open slide gate valve causes only a negligible pressure drop. Gate valves are very effective shut-off valves.

Since the gate inside an industrial gate valve takes a linear path through the center of the valve it can cut through thick fluids. This makes industrial gate valves ideal for situations that involve slurry or viscous fluids, like oils or grease.

Here are the main types of slide gate valves:

1. In a parallel gate valve, a flat disk divides two parallel seats to achieve shut-off.

2. In a double-parallel gate, two disks with an inclined plane lower between two parallel seats. Once the disks are fully down, the inclined plane presses the disks against the seats.

3. The two seats of a wedged-shape gate valve are inclined and the disc is somewhat mismatched to achieve higher sealing pressure.

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Shop quality gate valve manufacturers and gate valve suppliers

Gate valves are manufactured with a variety of materials. Also, keep in mind that gate valves are not generally built for high pressure applications, so their pressure ratings are not always published. Lastly, there are so many gate valve manufacturers and gate valve suppliers that comparing gate valve prices is a must.

I recommend: Grainger has a wide selection of gate valves from small to medium sizes. For larger industrial knife gate valves, see Tyco Flow Control, which carries much heavier-duty valves.

Be careful when choosing gate valves to throttle flow

Gate valves are not the best device if you need to achieve a full range of flow regulation. The disc can vibrate during flow, which erodes the seats and even the disc itself. However, there are some applications that involve infrequent throttling where knife valves may still be the right choice.

I recommend: Look to suppliers of gate valves that carry the heaviest-duty knife valves. NICO Valves Corp. manufactures some serious gate valves, but their selection is limited and somewhat specialized. Also, take a look at Clarkson valves, like the ones on Tyco's website, which pressure rate up to 300 p.s.i.

Maintain and repair your industrial gate valves

Check your valves regularly for leaks or corrosion. Planned repairs are much cheaper than sudden breakdowns.

I recommend: Davis Valve has an installation and maintenance manual for their products on their website, as do some other suppliers of gate valves. However, you may want to call in some help. That's where a company like Furmanite comes in, which services heavy industrial applications.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Knife or gate valves can be harder to clean than, for instance, ball valves. For that reason, they aren't ideal if sanitation is an issue.

Gate valves are another one of those valves that come in more than one configuration. As might be expected, each configuration is for a specific task. The main gate valve configurations are slide gate valves, rotary gate valves, knife gate valves and wedge gate valves.

In the information about gate valves, the application of the gate valve designs are explored, as well as information about gate valve manufacturers and suppliers of gate valves. This will help your company achieve making the most of gate valves, and finding the best gate valve for your company's application.

1. Use wedge gate valves with potable water, sewage and more.

2. Allow rolling slide gate valves control flow control and shut-off.

3. Use rotary shut off valves for temporary shut-off.

4. Rely on knife gate valves when processing pulp, agriculture, water management and more.

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Rely on wedge gate valves that are resilient and effective

Wedge gate valves can be made of ductile iron, carbon steel or stainless steel, and can be coated with epoxy on the interior and exterior. Some of them can be for use in fire protection systems, as well as for drinking water or sewage. Wedge gate valves can have a psi rating of 250, and can be 2 inches to 66 inches in diameter.

I recommend: American Cast Iron Pipe Company is a wedge gate valve manufacturer, as well as American Energy Services. Both are gate valve suppliers as well.

Use rolling slide gate valves for flow control and shut-off

Rolling slide gates are effective for controlling the flow as well as shutting off the flow completely. These gate valves have channels that are structurally heavy-duty, and are abrasion-resistant. Some of these valves have a bonnet. The blades are easily accessible for cleaning, and the rollers on the rolling slide gate valves can be re-greased.

I recommend: Two manufacturers of the rolling slide industrial gate valves are PEBCO and ShanRod.

Consider rotary gate valves for temporary shut-off

These gate valves work well in conjunction with air locks, because they allow you to remove the rotary air lock for maintenance. Some of the rotary gate valves come with a hand crank or a manually operated gate. These gate valves can be made of aluminum, stainless steel and carbon steel.

I recommend: Two manufacturers of the rotary gate valves are Horizon Systems and Plattco.

Research knife gate valves that are versatile and effective

Knife gate valves work well in the a variety of process industries. These gate valves often have hand wheels, a locking device for the fully-on or fully-locked positions and can have a fluid compatibility that is pH of 0-14.

I recommend: Velan and Automated Valve and Equipment are two of the many manufacturers of knife gate valves. As with many of the manufacturers listed above, these manufacturers make other styles of gate valves as well.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Contact the manufacturer and gate valve supplier for gate valve prices, as the gate valve price will vary. Ask about bulk discounts as well.

Gate valves are used in so many areas, but they all have the same general purpose - to control liquid flow. Training your employees to properly install and use valves is essential in keeping operations running smoothly. Training can include anything from a simple instruction sheet to a more complex training session, depending on the level of education needed.

Identifying the types of gate valves and knowing their proper uses is also important. Gate valves come in rising or non-rising stem valves, but within these categories, there are many other differences in types and uses. Making sure your entire organization is properly trained in the varying uses, gate valve prices and maintenance will save your company money in the long run. Start by:

1. Talking to your current or potential manufacturers and suppliers of gate valves.

2. Joining associations to find gate valves education and training opportunities.

3. Asking a professional organization to train your employees.

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Find educational materials through gate valve suppliers and manufacturers

Some of your fastest and most reliable gate valve training can come directly from the source. Ask gate valve manufacturers if they offer any training materials. Some even provide on-site training and refresher courses.

I recommend: Gate valve manufacturer American Flow Control has a library of videos that show gate valve operations and compare gate valves to other types of valves. Use the valve diagnostics tool from Velan to train employees about proper maintenance and problem solving gate valve issues.

Join an engineering or manufacturing association to get information about gate valves

Network with others who use gate valves to gain valuable insight into their workings and flaws. Get tips from organizations that have good valve retention and find out about the latest gate valve news and trends.

I recommend: Find current trends and prices of gate valves with help from the Society of Manufacturing Engineers, or join the American Society For Engineering Education for additional gate valve resources. Joining the National Society of Professional Engineers allows you access to federal, state and local groups that share your interests and involvements.

Use online gate valve training tools to educate your workforce

Training all employees who'll be working with gate valves is very important for their safety and your bottom line. Keep your equipment running smoothly, and make sure your employees stay safe by finding on-line training tools designed specifically for gate valve training.

I recommend: Get a printable gate valve overview at Integrated Publishing Engine Mechanics, or find a listing of valuable engineering resources including gate valve training information at EngNet.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Industrial gate valves are prone to corrosion, which makes proper maintenance and operation training very important. Make sure your maintenance crew is properly inspecting and caring for the valves by keeping your workforce trained.

A gate valve can be commonly seen in households as a water main shut off, but in a more complex function the valve is used in many industrial settings. The concept of the gate valve is simple: the valve is turned either to allow flow or to stop it.

Gate valves are often used at shut-off valves, or in more complex double block and bleed systems. Learn a few basic functions and terms associated with gate valves before choosing a valve for your job.

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Shut-off valves

A shut-off valve is defined as a valve that works to stop the flow of a liquid or gas. They can be manual or power. A gate valve is a type of shut off valve because it controls the flow by either completely opening and allowing liquid through, or closing to stop the flow.

I recommend: Read the definition of shut-off valve at ChemiCool.

Pressure reducing valve

A pressure reducing valve is one that eliminates excessive pressure in a tube or pipe. The valve usually is usually set up to release pressure automatically when it is needed. While the valve works similarly to a shut-off valve or gate valve, it is not the same thing because it is designed to release excess, not stop flow.

I recommend: The term pressure reducing valve is more fully explained at Valve World.

Double block and bleed

A double block and bleed is a system used to stop flow and drain the area of the pipe. The block and bleed uses a shut off at two ends with a release valve to allow the drain of liquid from the section.

I recommend: GMI Valves explains the double block and bleed concept in its glossary of terms. The glossary also includes many other valve terms that can be helpful in finding the right gate valves.

Stamped capacity

Most valves have a rating based on how much pressure or fluid they can handle at one time. The rating is normally 'stamped' on the valve, which gives it the name stamped capacity.

I recommend: ControlAndInstrumentaion.com explains the stamped capacity.

Pressure temperature rating

The pressure temperature rating is a similar term to stamped capacity, but with a more advanced configuration. This rating is based on the amount of pressure a valve can handle at any given temperature.

I recommend: The Valve Shop defines the pressure temperature rating and explains how it is determined for valves made of different materials.

Actuator

The actuator is the means of opening and closing a valve. The actuator can be pneumatic, electrical or hydraulic. These devices are commonly used when the actual valve can not be reached by hand or is too big to be operated manually.

I recommend: The actuator is defined in the GlobalSpec.com glossary.