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What does the pressure relief valve do on a boiler and why is it important to test it?

When it comes to the safe function of a boiler, a pressure relief valve is hugely important. For a boiler to function effectively and to the best of its ability, it is important that the pressure relief valve is maintained on a regular basis. But what does the pressure relief valve do on a boiler that makes it so crucially important? Leading pressure control equipment suppliers, Fluid Controls Ltd answer this and explore how to test pressure relief valves on boilers.

What does the pressure relief valve do?

On a boiler, the pressure relief valve is one of the most important safety aspects. It is used to ensure that the build-up of intensive pressure within the boiler can be relieved in order to avoid catastrophic accidents. It works as an open-close feature: opening when the pressure has built up to dangerous levels and closing once normal pressure levels have been reached.

It is because of this reason, the maintenance of the pressure relief valve is so important. Should the pressure relief in your boiler fail, it can lead to catastrophic accidents within industrial settings.

What causes a pressure relief valve to fail?

The recommended timescale for carrying out maintenance and testing on a pressure relief valve is 6 months. Leakage is usually one of the main things to look for when understanding what causes a pressure relief valve to fail in a boiler. This is usually caused by a build-up of substances such as mineral salt, rust, or corrosion.

This build-up of debris can prevent the pressure relief valve from seating properly. This can stop the water flowing through the boiler pipe as it should do so. This issue should be fixed or replaced as soon as the issue is identified to avoid a disastrous incident.

How to test pressure relief valve on boilers

So, the importance of regularly testing the pressure relief valve in a boiler has been defined. It is now important to understand how to test pressure relief valves on boilers. It is actually relatively simple and can be broken down into three simple steps.

  1. Raise and lower the test lever – performing this several times will lift the brass stem it is fastened to.
  2. Look for water flowing through the pipe. If the water passes through as it should, then turn down the water pressure.
  3. If no water flows through or very little flows through, then there is an issue with the pressure relief valve that will either need fixing or replacing as soon as possible.

As well as the above steps, there are also other components to look out for when testing a boiler’s pressure relief valve. They include:

  • Pipe length – should be the same diameter as the exhaust valve port.
  • Pipe material – needs to be heat resistant.
  • Drainpipe direction – should travel slightly downhill and finish between 6 - 24 inches from the ground.

Testing all of these components is extremely important for the correct function of your boiler.  Identifying these issues before they have the opportunity to escalate into a bigger problem makes it easier to find a solution, and maintain the high performance of your boiler moving forward.

For more information about the pressure relief valves that Fluid Controls distribute or any of their other products, visit www.fluidcontrols.co.uk

Company Profile

Fluid Controls
Fluid Controls Ltd

Fluid Controls Ltd is one of the UK’s leading distributors for pressure control for a wide range of industries.

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