A safety valve’s set pressure is the pressure at which it audibly opens for the first time. If you want to change the set pressure of your valve, it may be necessary to replace the installed spring.

Under normal conditions, the set pressure is equal to the Cold Differential Test Pressure. At temperatures above 100 °C or when compensating for back pressure on the outlet face, the Cold Differential Test Pressure may deviate from the set pressure.

With the Pressure Change web service you can find the right spring to change your valve to a new Cold Differential Test Pressure.

Follow these steps

Enter the article number of a valve and the set pressure in bar or psig to find the suitable springs. E.g.: 5262.0012 and 29 barg.
If necessary, several different spring materials will be issued. 

Please observe the application limits of your safety valve, as any springs displayed may be outside the permissible pressure range.

Please note that unauthorised persons are prohibited from changing the Cold Differential Test Pressure of a safety valve. In addition, after a pressure change, the safety valve must be sealed and re-stamped in accordance with the regulations.