Vacuum Relief Valve
Pressure relief valves are fitted into the adjoining pipework of an exhauster. They are set just beyond the blower's intended maximum vacuum and will open to allow additional air into the system until the correct vacuum level is reached. This protects the blower from overheating and seizing.
Vacuum relief valves are available upto a discharge pressure of -450mbarg
As there are many different vacuum relief valves available, it is always recommended that you know the make, model and settings of the relief valve you are looking to replace.
Alternatively, the connection size, system vacuum and airflow would be required for us to suggest an appropriate valve for your situation.