Relief valve
A blow-off valve is a valve of closed containers or pipes , with the lower pressure related media (mostly gases are) discharged (blown off). A distinction is made between automatically acting and manually operated relief valves.
An automatically acting relief valve acts as a safety valve and prevents the pressure in a pressure vessel from rising beyond the permissible level. These valves can usually also be operated manually; However, this is only used to check whether the valve is smooth and free.
A relief valve is used for the controlled release of substances from the pressure vessel during operation. For example, it is installed after the superheater to start up a steam boiler and is opened when the valve in the turbine line is closed. In steam boilers, the blow-down valve is located at the lowest point of the boiler and is used to regularly drain the sludge and solids that form in the boiler .
The mouth of the blow-off line is always attached in such a way that no one can be endangered by the escaping medium . In the case of hazardous substances , the medium is collected in a specially designed container.
