Safety devices 

For pressure reactor

Safety Rupture Discs

This is one kinds of one time safty device, which deisng a certain opening pressure value set for pressure autoclave safety. 

Pressure safety valve

The kinds safty valve can be adjust release pressure value in a pressure range. High pressure autoclaves are provided with built in safety rupture disc, however additional safety can be offered by providing pressure safety valve for which release pressure can be set manually by increasing or decreasing the spring tension or by simply changing the spring.  The set pressure should normally be around the design pressure.