Relieve excess pressure in your boiler system with a high-quality safety valve. These valves are a fail-safe that are designed to keep the system stable and help to prevent pressure excess across a range of manufacturing and industrial applications.

If you're searching for a pressure safety valve for your system or you need a new hydraulic safety valve, you'll find what you need here at RS. We stock products designed to suit different systems. These are made by trusted and established manufacturers and can be shipped to you today.

Read on to find out more about how safety valves can help prevent hazards by controlling pressure in systems where maximum pressure is likely to be exceeded.

What are safety valves?

The term 'safety valve' is used to describe a range of pressure relief devices. There are different types that are used for specific applications and it is crucial that the type of safety valve used matches the system. For instance, a hydraulic system will require a hydraulic safety valve and a pneumatic safety valve will be needed for any applications that use pneumatic systems.

The reason it is so important to match the valve to the job is that the main purpose of a safety valve is to protect both property and life. They are installed wherever it is probable that the maximum allowable working pressure (MAWP) of a system will be exceeded. This is sometimes referred to as 'overpressure'. Should overpressure occur, it can lead to system malfunctions, fire hazards or even explosions.

Safety valves just have mechanical parts, so they are activated when electronic or pneumatic safety devices fail. Therefore, as it is often the last device to prevent catastrophic failure when the MAWP is exceeded, it is essential that the safety valve works at all times. It must be a reliable device that can continue to operate if there is a power failure.

How do safety valves work?

Typically, a safety valve opens when an excess of pressure is reached. The valve first opens a little to relieve the pressure before opening fully so that the unwanted pressure is removed from the system as quickly as possible.

There are different safety valve types that operate slightly differently to each other. There are valves with a spring-loaded mechanism, ones with balanced bellows, and pilot-operated pressure safety valves.

The spring mechanism version is the most common. The spring holds the valve closed. When the pressure is greater than the force acting on the spring, it opens completely.

Balanced bellows are a special version of a standard safety valve. They include metal bellows that balance out the back pressure across the top and bottom of the poppet valve. This means the back pressure doesn't influence how the valve operates.

Pilot-operated safety valves have the poppet valve held in place on the nozzle by the pressure itself. Where the pressure increases, the main poppet valve presses in on the nozzle.

The type of valve you opt for will depend on the application you're using it for and the pressure levels that the system operates at.

Where can pressure excess occur?

Pressure safety valves are installed wherever there is a risk that the MAWP in a system or pressure-containing vessel could be exceeded. They are particularly required under fault conditions as a final tool should other pieces of equipment fail.

Therefore, they are most often used in industrial applications to protect against overpressure. Safety valves are often found in the oil, gas and petroleum industries. Here, there is a lethal element should equipment failure occur.

They are also found in the energy sector. In these situations, they discharge overpressure in boilers or gas, steam, air or liquid pipelines.

Some examples of where overpressure can occur include:

Plant fires
Compressed air or electrical power failure to control instrumentation
A cooling system failure, where fluid or vapor expands

H2: Where to buy safety valves

Whether you need a new hydraulic safety valve or you're searching for a replacement pneumatic pressure safety valve, choose RS.

We are a North America-based authorized distributor of safety valves, supplying the whole country. We stock well-known manufacturers, including Bimba MFD, Crouzet and Norgen. We're proud to bring you a range of safety valves that meet the highest industry standards of performance.

If you have any questions, we are happy to offer advice and tips. Get in touch with the team today. You can also find advice in our expert content hub.