Putting the pressure control panel into a safe condition

In the event of interruptions in operation for more than 5 days or pending maintenance or servicing, the pressure control panel must be put into a safe condition. First carry out the steps "Interruptions to operation for more than 48 hours".

The process gas source must be connected during flushing (see "Connecting the process gas source"). Also observe the "Preparations for commissioning" chapter.

To ensure high gas purity, pressure purging is to be performed as described below.

1. Close all valves and fully depressurise the pressure regulator by turning the of the handwheel anticlockwise as far as it will go.
2. Open slowly valves PGI and HPI to build up pressure in the system.
3. Slowly open the pressure regulator and build up pressure.
4. Close valve PGI.
5. Open valve PLI to reduce the pressure in the process gas line, then close it again.
   Repeat steps 2 to 5 depending on the gas type at least 3 times to remove impurities or foreign substances without leaving a residue. The pressure regulator remains pressurised.
6. Close all valves.
7. Fully depressurise the pressure regulator by turning the of the handwheel anti-clockwise as far as it will go.