A Guide to Pressure Relief Valves in Industrial Steam Boilers

As experts in a wide variety of boiler systems, our team recognises that industrial steam boilers are only efficient if all their valves are well fitted and perform correctly. That means ensuring the valves are calibrated efficiently and in pristine condition to withstand the boiler’s pressure. It can be easy to miss when an industrial steam boiler needs routine maintenance, so it’s important to pay attention when your pressure relief valve opens and assess if this is a symptom of a greater mechanical issue.

The purpose of the pressure relief valve

Often situated on the top or side of a steam boiler, the pressure relief valve has a nozzle that releases pressure to avoid building up to unsafe levels within the boiler. If the steam boiler reaches a certain pressure or temperature above the desired levels of the pressure relief valve, the valve opens proportionally to discharge steam until the pressure level’s kPa (Kilopascals) returns to safe operating levels. This spring-operated valve ensures that the pressure in the system is always within safe operating levels and avoids rupture of the boiler drum.

It is important to determine why your pressure relief valve is open as there are two main reasons for steam release: the system’s pressure is too high or the valve needs to be repaired.

Situation 1: The boiler pressure gauge reveals the pressure is too high

If you note that the pressure relief valve is discharging pressure, it’s integral to look at the pressure levels of the system. The steam boiler’s pressure gauge is often located on the side of the boiler and can be indicated on HMI, so be sure to check if the pressure is within safe levels of operation. Depending on the age of your steam boiler model this could be within 75 to 100 kPA. If the levels are too high and the pressure relief valve is open, then the valve is performing as required and reducing the pressure within the system to safe levels. If the boiler’s pressure often climbs to higher-than-expected levels, it is important to get the system evaluated by a professional.

However, if the pressure gauge reads that the steam boiler is within or under the maximum pressure levels, then this could be a sign of an issue within the pressure relief valve or the steam boiler system.

Situation 2: The boiler will not reach optimal pressure or the leak is constant

If you notice the pressure within the steam boiler is not increasing or dropping unexpectedly, it’s important to check the pressure relief valve. If the gauge of the pressure relief valve reads little to no pressure, it could be an issue of an ill-fitting valve that requires replacement. Whether it’s a simple misalignment or a broken spring, a malfunctioning pressure relief valve should halt production immediately to protect the safety of the boiler operator.

If the pressure levels are dropping but steam is not escaping from the pressure relief valve or drain, there could be a leak elsewhere within the boiler. When suspected leaks are detected, it’s important to stop operating the steam boiler until it has been repaired and tested following your company’s steam boiler safety protocols.

Still uncertain about the safety of your pressure relief valve?

If the pressure relief valve doesn’t seem to be performing as required, it may be time to organise a replacement from an expert maintenance provider. Over time, sediment from steam can build up within the valve, leading to clogs or warpage that prevents it from sealing or maintaining pressure causing continuous steam leakage. Leaks will prevent the boiler from reaching the desired pressure, so it is important to adhere to a strict maintenance schedule and routinely check for wear and tear in your industrial steam boiler.

Regulations require that all Safety Valves fitted to Steam Boilers have a NATA Certified testing and tagging – Tomlinson Energy Service offer this service through Valve OSR in our South Australian Branch and can arrange this service throughout Australia.

Is your industrial steam boiler in need of maintenance?

Tomlinson Energy Service has provided premium industrial and commercial boilers and repairs to Australia for over 100 years. Our expert team are available for all your boiler service needs with 24/7 boiler and gas burner maintenance and repair. If your steam boiler has not been performing optimally or needs replacement parts, our knowledgeable and friendly specialists are here to help.

If you would like to get in touch with our team today, then please call us on +61 3 8560 0419 or fill out the contact form below.