MKS Series 225 Auto-Soft Start Check Valve Flow Actuated, Spring Loaded, No Voltage
NW40 KF40 Viton Centering Ring - STAINLESS STEEL
The MKS 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.
This is a simple NW KF Valve fitting for automatic soft starts. The Auto-Soft valve has a vane that pivots about an off-center axis. A pair of coil springs hold the vane open
when the pressure differential is low enough. When the roughing system goes into operation, the
initial flow closes the vane assembly, automatically throttling the roughing pump. Initial pumpdown occurs through small openings around the vane. This reduces the effective
pumping speed, which minimizes turbulence and extends pumpdown time. When the pressure
differential reaches the level determined by the springs, the springs open the vane and full
pumping speed is restored.
When installing the Auto-Soft, adequate space is needed, the amounts are listed in the
specifications table. The user can adjust the closed conductance of the valve over a limited range
by bending tabs adjacent to the vane.
The Auto-Soft should be installed between the vacuum system and the roughing valve. Trapping
of contamination before the Auto-Soft will help to ensure a long life.
FEATURES & BENEFITS:
- Reduces particulate contamination by
reducing system turbulence during venting
- Prevents displacement or breakage of substrates
- Replaces expensive pressure controlled bypass systems
- No electric - flow actuated
- Operates up to 10,000 cycles
For a complete explanation of this MKS Auto-Soft Check Valve see .pdf to the side.
