Maintenance of a Boiler’s Pressure Relief Valve

The key to keeping your boiler performing better for longer is to carry out routine basic maintenance, often boiler pressure relief valves can stay in service for up to 30 years when maintained correctly. Here at Fluid Controls we advise carrying out maintenance on your water heater every six months particularly to protect against leakage caused by mineral and corrosion build-up or greater internal system problems.

Your boiler may seem like a big bit of kit – but it’s quite simple to test your boiler’s pressure relief valve, we will help you explore the hows, why, and where’s when tackling the job.

What is a boiler pressure relief valve?

A boiler pressure relief valve can also be known as a safety relief valve – they are used as a safety feature to prevent the build up of pressure and come in many different valve types. The valve works by releasing pressure when levels ever exceed the normal and closes again when the pressure returns to a safer range. 

Why pressure relief valve testing is important

One of the main components to relief valves becoming non operational is the build up of minerals, salt, rust, and corrosion. By testing your valve every six months, you can prevent or find problems sooner which will make issues easier to combat and ensure your boiler performs optimally for the foreseeable future.

Before you test your boiler’s pressure relief valve

There are a number of factors to look out for when testing your boilers pressure relief valve, aspects you may want to consider are:

• Pipe length – The pipe leaving the valve should be the same diameter as the exhaust port of the valve.
• Pipe material – The pipe should be made from a material that is resistant to heat, such as copper. Most boilers will already utilise this material, but if not, it is important to get it updated.
• Drainpipe direction- The drainpipe should travel slightly downhill, from where the valve starts to where it terminates, finishing between 6-24 inches above the ground.

How to test a boiler’s pressure relief valve

Testing a boiler’s pressure relief valve is extremely simple:

1. Raise and lower the test lever several times and by doing so, it will lift the brass stem that it’s fastened to. 
2. Once the lever has come away from the stem, hot water will rush out of the end of the drainpipe. 
3. If the water flows through the pipe like it should be doing, turn down the water pressure to stop the leak.
4. Replace the lever and increase the pressure. 

Keep an eye out for – If no water flows through the pipe, or there is just a trickle of water, you will have to take action.

One of the reasons why the valve may not be operating the way it should be is, if debris has been lodged. This may mean that debris is preventing the valve from seating properly. 

The fix – simply operate the test lever several times. If this doesn’t work, you may need to replace the valve.

Pressure relief valves are an important aspect of any machinery where media is being used at high temperatures or pressures. When you routinely check your pressure relief valve you can notice ​​symptoms of other internal problems, quite often a malfunctioning pressure relief valve may indicate a greater problem. Checking allows you to look at the “why” behind possible failure, rather than just replacing the valve in question. Although valves have a good longevity they do sometimes need replacing and we can help! 

Fluid Controls are leading suppliers of pressure relief valves from Parker, suited to industrial applications. Learn more about the work we do or get further information, please contact (0)118 970 2060 or email fluid@fluidcontrols.co.uk.