Safety Relief Valves

Safety Valve Technical Information
Bailey Safety / Relief Valves Technical Information
Safety Relief Valves
By John Valves
These valves work as safety devices, protecting pressurised equipment or systems during an overpressure event. If the pressure increases beyond what the equipment or piping system is designed to handle, catastrophic damage can occur to the system itself, as well as plant and personnel.
The primary purpose of safety and relief valves is to automatically discharge gas, vapour or liquid from any pressure containing system, to prevent a predetermined safe pressure being exceeded.
We locally manufacture and supply a range of certified safety and relief valves including:
- Bronze safety and relief valves
- Stainless steel safety and relief valves
- Cast steel safety and relief valves
John Valves is also the Australian Agent for Bailey Valves.
Relief Valves
Our relief valves are ideal for relieving excessive pressure within a pressurised system. Once a predetermined upstream pressure is exceeded, the relief valve opens automatically, discharging the fluid. A relief valve has a closed cap and tamper-proof tag.
These valves are designed to safeguard your system from becoming over pressurised and prevent system failure. They are typically used on liquid service applications.
Safety Valves
Our safety valves are designed to protect people, property and processes. They provide a failsafe, last resort pressure release to avoid a catastrophe. A safety valve automatically discharges gases and vapours to prevent a predetermined safe pressure from being exceeded. It is characterised by a rapid full opening action and is used for steam, gases or vapour service.
Safety valves are normally supplied with an easing lever so that the valve can be manually operated to ensure that binding or sticking of the valve disc is not occuring.
Frequently Asked Questions About Safety Valves
Got questions? Below are some of the questions we get asked often about safety relief valves.
Both safety and relief valves let off pressure in cases of system overpressurisation. However, whilst their objective is ultimately the same, they function slightly differently. Relief valves control pressure by opening in proportion to the increase in system pressure. Safety valves stop pressure build up altogether by opening immediately and fully to avoid disaster.
Sizing a safety or relief valve correctly is vital. It’s also a complex process. However, there are many methods and tools available for correct sizing. There are several equations depending on flow conditions such as liquid, gas and steam, for example.
Our team of experts at John Valves are more than happy to assist you in choosing and sizing the right valves for your application.