What Are Pressure Relief Valves and How to Properly Install Them?

A pressure relief valve as the name indicates provides relief or protection against overpressure in a pressurized system. When the pressure in a vessel or system goes beyond its limits or exceeds the maximum allowable working pressure it is known as an overpressure event. This is where the pressure relief valve like 3 bar pressure relief valve comes into play. Fluid system variables such as pressure, temperature, and flow are controlled by electronic pneumatic and hydraulic systems. Each of these systems require a source from which it can draw its power to operate like electricity or compressed air. A pressure relief valve is expected to perform its function normally even at the times of power control failures in systems when they become uncontrollable. The process fluid is thus considered the only source of power for the pressure relief valve. 

Installation of Pressure Relief Valves

Proper installation of pressure relief valves is a very critical factor in ensuring safe operating pressures. If they are not installed in the correct manner it can lead to some dangerous outcomes.


The following steps should be taken into account to ensure that the 3-bar pressure relief valve is installed properly. If not installed correctly then it can lead to leakages and post safety problems. 

Remove Dirt and Debris

When a lot of dirt and debris go into the system it can cause damage to the seat of the valve, therefore you must flush the system to remove any kind of dirt and debris also preventing them from getting into the valve like 3-bar pressure relief valve Screwfix prior to installation. Additionally, you should make sure not to install the valve in a place where any sort of dirt and debris can be collected. Hence taking precautions is better then later on dealing with the consequences. 


  • Firstly, you need to mount the safety valves in a vertical position because it performs effectively in an upright position. Whereas, installing it in a horizontal positional can lead to problems and improper functioning. 
  • When you are using flanged versions all the bolts need to be tightened fairly and equally. If they are not tightened equally that can effect the tightening of other bolts. Valves that are made from cast iron may even crack due to the uneven pressure loads exerted.
  • Tightening it to enough amount is important but preventing over tightening of the valve is even more important. Both inlet and outlet threads can be damaged due to too much pressure which can lead to leakages.
  • To prevent contamination of your system, apply sealant to the male thread and not to the female thread. If the valve is too tall, as much as 10 feet above a vessel then support is required. If there is no support then the valves and other parts of the systems will be damaged due to the reaction forces in a 3-bar pressure relief valve Toolstation. 

Inlet Piping

  • The inlet piping system must be short and direct. The diameter of the inlet piping should always be bigger than or equal to the valve inlet diameter like 3-bar pressure relief valve 15mm. This will compress the flow. 
  • Make sure that the inlet is not installed in a vessel near areas that have high turbulence.
  • Make sure that the process lines are not connected to the relief valve inlet piping.
  • Make sure that you install the valve with a diameter of at least 8 to 10 compared to the Y bending fittings.

Valve Operation

For the valves like 3-bar pressure relief valves to properly operate it is necessary that their set pressure is at least 10% higher than operating pressure to make sure any leakages do not occur. When the valve pressure approaches 80% or 90% then it will result in relief valve leakages.


If you do not have much time to test out the valves more frequently at least make sure to test them once a year. Sometimes testing often poses risks of dirt and debris getting into the system and leading to leakages. 

Installation for Steam Systems

In steam systems relief valves are commonly used for safety purposes. It is important to avoid collecting condensate on the upright part of the valveā€™s disc by making sure to install them properly. This can be achieved by the installation of the valve above the steam pipe. But if you install it below the pipe then this can lead to the collection of 3-bar pressure relief valve compression in the connection to the valve. This can cause enormous amounts of damage to the valve seat and its operations.