ULVAC Vacuum Valves
Vacuum valves are critical elements of every vacuum system. Gate valves isolate turbomolecular pumps from process chambers, angle valves connect rough pump lines, butterfly valves throttle conductance for pressure control, and solenoid poppet valves provide fast-acting isolation on gas and purge lines. This page covers the full ULVAC valve range including GV, GVB, AV, BFV, EV, and PV series.
Part Numbers
Valve Type Selection
| Type | Application | Key Selection Criteria |
|---|---|---|
| Gate valve (GV/GVB) | High-conductance isolation between TMP and chamber | Flange size (NW40 to ISO320); manual or pneumatic actuator |
| Angle valve (AV/AVB) | Compact isolation with 90 degree flow change; foreline and roughing lines | Flange size; bellows seal or elastomer seal; manual or actuated |
| Butterfly valve (BFV) | Throttle control and isolation; rough vacuum throttling | Flange size; manual, pneumatic, or motorised actuator |
| Solenoid poppet valve (EV) | Fast-acting isolation on purge and vent lines | Orifice size; voltage (AC100V to AC480V, DC24V); fail-open or fail-closed |
| Poppet valve (PV) | Normally-closed gas valves; purge inlets; venting | Orifice size; actuator type; gas compatibility |
Installation Requirements
- Gate valves: mount with bonnet upward or horizontal — do not invert
- Confirm flange standard before ordering — NW/KF, ISO-K, ISO-F, and ConFlat CF are not interchangeable
- Pneumatic valves: supply clean dry compressed air or nitrogen at 0.4 to 0.7 MPa
- Solenoid valves: verify coil voltage matches supply — available voltages: AC100V, AC200V, AC220V, AC380V, AC400V, AC415V, AC440V, AC460V, AC480V
- Bellows-seal valves: protect bellows from mechanical shock or side-loading during installation
- Verify o-ring material (Viton standard) is compatible with process gas
Commissioning Checks
- Verify valve moves fully open and closed with smooth operation
- For pneumatic valves: verify correct fail-safe position on air pressure loss
- Leak test valve body and flange joints with helium sniffer or pressure rise rate monitoring
- For automated valves: test position sensor signals at interlock controller
- For solenoid valves: verify correct current draw and cycling on control signal
Preventive Maintenance
- Manual gate and angle valves: inspect gate o-ring and stem seal at each system open or annually
- Pneumatic actuated valves: check air cylinder seal condition and actuator stem wear annually
- Bellows-seal valves: inspect bellows at each PM — any failure requires immediate valve replacement
- All valves: clean seating surfaces at each system open with lint-free cloth and IPA
- Solenoid poppet valves: check coil resistance at each PM
Fault Diagnosis
| Symptom | Cause | Action |
|---|---|---|
| Valve leaks through when closed | Worn seat o-ring; contamination on seat | Inspect seat; replace o-ring |
| Pneumatic valve does not open | Air supply pressure low; pilot solenoid failed | Check supply pressure min 0.4 MPa; test solenoid coil resistance |
| Valve stiff to operate | Lubricant depleted; debris on slide surfaces | Clean stem; re-lubricate with vacuum-compatible grease |
| Position sensor shows wrong state | Sensor misaligned; dirty; wiring fault | Re-align sensor; clean face; check wiring |
| Bellows valve — external leak at stem | Bellows ruptured | Replace valve immediately |
| Gate valve will not seat | Seat o-ring damaged; debris on seat | Vent system; open valve; inspect seat and o-ring; replace |
Training
Training covers: valve actuation sequences, interlock logic, o-ring replacement, pneumatic actuator service, leak testing, and position sensor adjustment. Contact mail@ulvacheliot.com — provide: valve models in system, number of attendees, site location.
Spare Parts and Service Enquiry
Email mail@ulvacheliot.com — provide: valve model, part number, flange size and standard, o-ring material, actuator type, and fault description.