The purpose of a relief valve
A pressure relief valve is a safety device fitted to the boiler or system and must be able to discharge externally to a drain where the discharge can be seen but cannot cause any injury or damage. No other valves should be positioned between the relief valve and discharge termination.
The pressure relief valve should be manually activated periodically in order to asses valve opening, normally as part of servicing.
This valve is for 3 Bar pressure.