Series 225 AUTO-SOFT® Flow-actuated Check Valves – MKS

The HPS® Series 225 Auto-Soft is a flow actuated check valve used for throttling roughing pumps during initial evacuation. Auto-Soft closes very quickly at the start of system evacuation and opens automatically upon reaching a set pressure differential. This leaves the pumping line open for the balance of the pumping process.

In the semiconductor, thin film, and other industries, Auto-Soft replaces pressure controlled bypass valves to provide a soft start. The soft start then reduces turbulence in the vacuum system. Particles resident in the system are not stirred up and the work in progress is not damaged.