MKS Sentry 145-0050K-208V/60 Vacuum Safety Valve, ISO-KF Flanges, NW50 Angle Ports, Viton Seals, 208 VAC/60 Hz

• Type
• Safety Valve
• Body Configuration
• Angle
• Port Size
• NW50
• Helium Leak Rate
• <1 X 10-9 std cc/sec He
• Body Materials
• AL 6061-T6
• Seal
• Viton®
• Closing Burst
• 1 X 10-3 T-1
• Power
• 208 VAC
• Piston Material
• AL 2024
• Guide Pin Material
• Viton®
• Closing Time
• 30 ms
• Maximum Operating Temperature
• Valve: 100° C
• Solenoid: 55° C
• Venting Time
• 10 s/l of vented volume

Vacuum Sentry’s solenoid valve is connected in parallel with the mechanical pump’s electrical supply either at its source or at the pump’s switch. When the electrical power is on, the solenoid valve is held closed, allowing the pump to keep Vacuum Sentry’s body and the vacuum system evacuated. Interruption of electrical power to the mechanical pump causes the solenoid valve to open, admitting air into the Vacuum Sentry, causing it to close. This isolates the vacuum system. The pressure differential between the outside atmosphere and the vacuum system provides the force to maintain the valve in its closed position without electrical or pneumatic power. With the vacuum system isolated, a series of small orifices admits air into the inlet port of the mechanical pump until it has risen to atmospheric pressure. When the power comes back on, the solenoid closes the pump. The mechanical pump is then restarted, and evacuates the area above the piston until the pressure is lowered to approximately that of the vacuum system. Vacuum Sentry opens again allowing the vacuum system to be pumped at the full speed of the mechanical pump.