Relief valves come in many different types and are used on all sorts of equipment, from refrigeration machines to water heaters. Whether you're using a pressure relief valve, an air relief valve, a safety relief valve or a water pressure relief valve for your particular equipment, it's best to know at least some basics about installation and maintenance for relief valves.

Information about installing and maintaining relief valves can be found in manuals and instructional videos from relief valve manufacturers, or from literature through relief valve distributors or relief valve suppliers. If you're dealing with larger, industrial relief valves, you'll benefit from using professionals for installation and maintenance.

1. Check out safety valves manufacturers for links to installation manuals and other materials.
2. Look for companies that offer installation and maintenance for relief valves.
3. Perform any needed maintenance on your relief valves to keep them operating correctly.
   

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Get installation instructions for relief valves from those who know best

Perhaps no one would know better how to install relief valves than those who manufacture the valves themselves. If you're a do-it-yourselfer, or have an employee handle relief valve installation, you can find out all about the installation of relief valves through manufacturer manuals and videos offered by relief valve manufacturers or suppliers.

I recommend: Tyco provides links to a long list of installation and maintenance manuals for Anderson Greenwood and Cosby pressure relief valves and safety valves. Aquatrol gives some basic instructions concerning the installation of their relief valves on their website. Primary Fluid Systems provides installation instructions for high temperature and high pressure relief valves.

Seek the services of professionals when it comes to larger relief valves

You may work with equipment that requires use of larger, industrial-sized relief valves. These can be more difficult when it comes to installation and maintenance. If you're working with heavy-duty relief valves, it might be best to let a professional service handle installation and maintenance of relief valves.

I recommend: Industrial Valve uses state-of-the-art diagnostic tools to troubleshoot, repair and maintain your industrial safety and relief valves. The professionals at F.H. Gaskins Co. set and test your relief valves on-site. Flotech specializes in the repair, refurbishment and testing of relief valves.

Create a maintenance schedule to keep your relief valves working smoothly

Though many relief valves are advertised as being 'maintenance-free', most relief valves need to be checked periodically. At the least, relief valves may need to be cleaned or reset. Since relief valves work as safety mechanisms, it's a good idea to maintain them as frequently as possible.

I recommend: Maintenance World lists many troubleshooting tips you can use when checking relief valves during proper maintenance. Plast-O-Matic Valves offers links to maintenance guides for many types of relief valves.

Whether your pipe or tube system runs air, steam, gas or liquid, pressure relief valves significantly increase safety for your system and workers. Most pressure relief valves do not restrict flow. When pressures exceed safe levels within a system, the relief valve opens and lets steam, gas or liquid escape. This prevents the system from rupturing or, in some cases, exploding.

The pressure level at which a relief valve will open is often built in, but the alternative is an adjustable relief valve. A coil or hydraulic spring holds a relief valve closed. When pressure levels rise too high, the pressure compresses the spring to open the relief valve. Once pressure falls down to a normal range, the relief valve closes again.

Relief valves are different from other valves, but they are available in several common forms, including:

1. Diaphragm relief valves

2. Globe relief valves

3. Swing check relief valves

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Find quality relief valve suppliers and relief valve manufacturers

Relief valve applications cover a wide range. Look for sites that have a versatile selection of relief valves so that you can get a good match for your specific application.

I recommend: Grainger does a nice job of categorizing their products On their site you can quickly locate and buy a low pressure relief valve, liquid or water pressure relief valve, safety relief valve, tank relief valve or one of many other relief valves. You can also find an air relief valve among their pneumatic modular FRL accessories. If you're dealing with liquids, especially corrosive liquids, then also check out Plast-O-Matic Valves, Inc..

Buy large industrial relief valves from leading pressure and safety valves manufacturers

Some applications require very large or specialized relief valves. If these are the kinds of valves you're looking for, you will need to find a manufacturer that produces equipment at that level.

I recommend: Tyco Flow Control carries serious pressure relief valves from Anderson Greenwood, Crosby and Varec. Industrial Valve sells basically the same list of brands, but is a good place to do a price comparison or check for alternate availability.

Maintain and repair your relief valves

A faulty relief valve is a serious safety hazard. Maintain, repair and replace your relief valves as needed, without delay.

I recommend: Besides selling relief valves, Industrial Valve also repairs safety relief valves of all brand and sizes. Superior Industrial Valve Repair specializes in maintenance and reconditioning. Furmanite is another excellent choice for valve repair services, and an added benefit is that valve repair is only one of many repair services they perform.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  A relief valve can also refer to a device that pumps air into a low pressure system to prevent a vacuum from forming inside the equipment.

It’s important to choose a pressure relief valve that operates efficiently and effectively protects plant systems from handling too much pressure. Overall, relief valves control, maintain, record or meter air, gas and steam through pipes, tubes and hoses. Applying too much pressure to relief valves results in equipment failure or even fires. Pick equipment such as a water pressure relief valve, an air relief valve, a multiport relief valve or an adjustable relief valve depending on the relevancy to your business. These devices have applications in the HVAC, food processing, plumbing, and agriculture and irrigation industries.

Find relief valve manufacturers that offer a wide variety of safety relief valves that fit within the scope of your projects. Relief valves pricing and costs range from $50 to approximately $700, depending on the size, type, material and application. Some safety valves manufacturers require you to call or send online inquiries to determine price quotes.

1. Pick relief valves based on capabilities and energy efficiency.

2. Explore new versus used options for devices like safety relief valves, air relief valves, pressure or water relief valves.

3. Set aside a budget for maintenance and repair costs of an air relief valve or pressure relief valve.

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Choose relief valves based on quality and production capabilities

Buy reasonably priced equipment from relief valve manufacturers without compromising quality or energy use. The overall goal of the air relief valve, water relief valves and others is to protect fluid control devices from overpressurization and buildup.

I recommend: Watts Water Technologies stocks relief valves that are intended for fire protection applications. Relief valve manufacturers such as Valve Check manufacture devices that are self-cleaning and quick opening for proper ventilation. Safety valve manufacturers like Aquatrol supply relief valves that fit in with gas, air, liquid and steam applications.

Consider a used safety or adjustable relief valve over new

Safety valves manufacturers often provide used equipment for sale, as well as renting and leasing options to help your bottom line and to stay within budget.

I recommend: Find new and used pressure relief valve products at SmartProducts. Stra-Val also maintains a large inventory of relief valves and parts. For safety valve rentals, turn to Gulf Valve Service Company. Choose from weekly, monthly or extended rental services.

Remember to include maintenance fees when studying relief valves pricing and costs

Include the average costs of repairs and maintenance services, whether you're considering a water heater relief valve, a miniature relief valve or an air relief valve.

I recommend: Thorco Holdings offers repair and emergency response services for pressure relief valves and other types. Certified Safety Valve Repair specializes in maintenance and consulting services. Ware also features preventative maintenance options as well as tips.

A relief valve is a valve used to limit pressure in a specific tank or pipe system. This valve is used in systems where pressure is built up through fire or equipment failure. The pressure is relieved when the valve is adjusted or released, letting the pressurized gas or liquid flow out of the system into a separate tank. Most relief valves are made to open automatically when a specific level of pressure is reached. Once the pressure level returns to normal in the main system, the relief valve will close again.

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Flare header, relief header

The relief header, also known as a flare header, is the piping system used to relieve pressure from the main system. When a relief valve is opened, the excess liquid or gas is released into the relief header and eventually out into the atmosphere.

I recommend: John M. Campbell provides information about the common problems associated with relief headers in pressure relief systems.

Balanced pressure relief valve

A balanced pressure relief valve is a spring loaded valve that works to minimize the impact on the valve's performance due to back pressure.

I recommend: Integrated Publishing provides information on the poppet-type selector valve, which is made in unbalanced and balanced versions.

Conventional pressure relief valve

A conventional pressure relief valve is a spring loaded valve. It releases automatically when changes to the back pressure on the valve occur.

I recommend: Chemical & Process Technology provides information on the impact of back pressure on the conventional types of pressure relief valves.

Maximum allowable working pressure

The maximum allowable working pressure is the highest level of pressure allowed inside the system at a set temperature. This is the level of pressure that determines the need for relief devices for protection.

I recommend: The Engineering Toolbox provides a chart that determine the maximum allowable working pressure for carbon steel piping systems.

Pilot operated pressure relief valve

A pilot operated pressure relief valve is a system where a main and auxiliary valve work together to relieve pressure. The auxiliary valve controls to main valve.

I recommend: Tyco Valves and Controls provides information on a number of pilot operated pressure relief valve models for flowing and no-flow tank systems.

Required discharge area

The required discharge area for a pressure relief valve is the calculated area of pressure that determines the size of the valve used.

I recommend: Rockwood Swendeman provides calculations to perform in order to determine the flow area and the size of the relief valve needed for a particular system.