Compare Model Drawings, CAD & Specs Port Size Solenoid Voltage Availability Price
Vacuum Safety Valve, ISO-KF Flanges, NW25 Angle Ports, Viton Seals, 120 VAC/60 Hz
$465
3 Weeks
NW25 120 VAC/60 Hz
3 Weeks
145 vacuum sentry vacuum safety valve
Vacuum Safety Valve, ISO-KF Flanges, NW25 Angle Ports, Viton Seals, 220 VAC/50-60 Hz
$465
3 Weeks
NW25 220 VAC/50-60 Hz
3 Weeks
Vacuum Safety Valve, ISO-KF Flanges, NW25 Angle Ports, Viton Seals, 24VDC
$465
3 Weeks
NW25 24 VDC
3 Weeks
Vacuum Safety Valve, ISO-KF Flanges, NW40 Angle Ports, Viton Seals, 120 VAC/60 Hz
$490
3 Weeks
NW40 120 VAC/60 Hz
3 Weeks
Vacuum Safety Valve, ISO-KF Flanges, NW40 Angle Ports, Viton Seals, 208 VAC/60 Hz
$490
3 Weeks
NW40 208 VAC/60 Hz
3 Weeks
145 vacuum sentry vacuum safety valve
Vacuum Safety Valve, ISO-KF Flanges, NW40 Angle Ports Viton Seals, 220 VAC/50-60 Hz
$490
3 Weeks
NW40 220 VAC/50-60 Hz
3 Weeks
Vacuum Safety Valve, ISO-KF Flanges, NW50 Angle Ports, Viton Seals, 120 VAC/60 Hz
$510
3 Weeks
NW50 120 VAC/60 Hz
3 Weeks
Vacuum Safety Valve, ISO-KF Flanges, NW50 Angle Ports, Viton Seals, 208 VAC/60 Hz
$510
3 Weeks
NW50 208 VAC/60 Hz
3 Weeks
145 vacuum sentry vacuum safety valve
Vacuum Safety Valve, ISO-KF Flanges, NW50 Angle Ports, Viton Seals, 220 VAC/50-60 Hz
$510
3 Weeks
NW50 220 VAC/50-60 Hz
3 Weeks

Configuration Options

Description
  145 vacuum sentry vacuum safety valve 145 Safety Valve, Vacuum Sentry, Pump Failure Protection

Specifications

  • Type
    Safety Valve
  • Body Configuration
    Angle
  • Port Size
    NW25, NW40, 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
    7 W @115 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

Features

Vacuum Sentry Operation

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.

Maximizes Pumping Conductance

Vacuum Sentry is constructed of vacuum compatible materials and maximizes pumping conductance. Lifetimes in excess of 100,000 cycles are typical, which translates into years of trouble free use in suitable environments. The opening burst is less than the critical backing pressure for turbomolecular and diffusion pumps when appropriately sized mechanical pumps are used. The closing burst is minimized by the buffer volume design. Vacuum Sentry consumes little power. Installation is simple, because the standard ISO-KF dimensions are used for the NW 40 and NW 50 sizes. This allows the valve to replace elbows, tees, and crosses of the same size. Even when the mechanical pump is equipped with an anti-suckback valve, Vacuum Sentry should be used, because the pump’s integral valve will not vent it.

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