21700 Series Stainless Steel 3-Position Gate Valves


The 3-Position Gate Valves are designed for use in etching, CVD and any other process that requires pressure control. When used in conjunction with upstream mass flow controllers, this series valve will contribute to an exceptional pressure control capability. These valves may also be utilized to smooth the transition from rough to high vacuum. The valves employ two pneumatic solenoids and an air pressure regulator to achieve the three positions of fully open, fully closed, and an adjustable third position. One solenoid controls the fully open and fully closed positions while a second solenoid controls the third position.

Standard Technical Specifications


Valve body and gate: 304 stainless steel

Welded bellows shaft seal: AM-350

Drive shaft and pin: Hardened stainless steel


Pressure Range: 1×10-9 mbar

Helium leak rate: <2×10-9 mbar l/s

Differential pressure closed: 1 bar in either direction

Maximum Δ pressure before opening: < 30 mbar


Pneumatic air service: 80 psig

Solenoid: 4.0 Watts

- supplied voltage: 120V AC, 50/60 Hz

- optional voltages: 24, 200, 240 VAC, 50/60 Hz

Position indicator, max

- Reed switch for open & closed: 115 VAC or 28 VDC, 20 mA

- Microswitch for third position: 115 VAC, 5 A

- optional voltages: 250 VA, 5 A or 28 VDC, 5 A resistive load 28 VDC, 3 A inductive load


1,000,000 cycles

Cycles until service: dependent on process

Bonnet/gate seals

HV: Viton® elastomer

Helium leak rate: <2×10-9 mbar l/s

Differential pressure closed: 1 bar


Body: 150°C

Actuator: 60°C

Mounting Position


Use the table below to obtain 2D drawings (PDF) and 3D drawings (STP), or to request a quote.

If you need help finding a model number use the following link: 21700 Series Model Key Guide

3-Position (includes elastomer seals with 120V AC solenoid and position indicators)

DNModel NumberKF/ISO-F
3 (Bolted)
6 (Clamped)
0 or 4 (Conflat)

Flange Types

  • 0 = CF-F Port with UNF Thread (21712-0400R)
  • 3 = KF/ISO-F Bolted (21712-0403R)
  • 4 = CF-F Port with Metric Thread (21712-0404R)
  • 6 = ISO-K Clamped (21712-0406R)


  • JIS, ASA and Custom flanges
  • Alternate o-ring material
  • Alternate solenoid voltages
  • UHV copper bonnet version
  • Roughing ports