3-Way Vacuum Valve, KF NW40 / NW50
Switch one vacuum pump between two chambers, or vent a line, with a quarter turn. Polished 316 three-way body, KF (NW) flanges NW40/NW50 — manual lever (V-3WV) or pneumatic, DA or spring return.
Built to hold, built to last.
This is a pneumatic 3-way vacuum valve: a polished 316 three-way ball body with KF (NW) clamp flanges, driven by a rack-and-pinion air actuator. One quarter turn switches a vacuum pump from one chamber to the other, or opens a line to atmosphere, so a single valve replaces two two-way valves and the tee between them. As a vacuum switching valve it runs from a PLC output like any other air actuated device.
Two sizes: NW40 (1-1/2", Ø38 bore) and NW50 (2", Ø46 bore). Both are 181 mm end to end. Choose an L-port 3 way valve to route flow between two of the three ports, or a T-port 3 way valve when you also need the straight-through position. KF clamp flanges mean no bolts — a clamp and a centring ring, and the valve comes off the line in seconds, which matters on a vacuum ball valve that has to be opened for cleaning.
Bodies are cast A351 CF8M (316) and polished; CF8 (304) is available to order. Seats are PTFE and the valve runs from −20°C to 180°C. Actuators are double acting or spring return on a 4 to 8 bar supply, mounted on the ISO 5211 pad. As a Taiwan vacuum valve manufacturer we size, mount and cycle-test every assembly before it ships.
The same valve also comes as a manual build (V-3WV): the actuator comes off and a quarter-turn lever with a locking plate sits on the same ISO 5211 pad. Body, flanges and seats are identical. Pick the lever when the line is switched a few times a day or there is no air supply at the valve — it does the same diverting work between a pump, a chamber and a vent line, by hand.
Need the pilot valve as well? Our solenoid valve for pneumatic actuators is NAMUR direct mount, bolts straight onto this actuator, and ships assembled and tested with the valve.
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V-3WV · Manual
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Pneumatic · DA / SR
- Body
- A351 CF8M (316), polished
- A351 CF8M (316), polished
- Made to order
- CF8 (304) to order
- CF8 (304) to order
- Size range
- NW40 (1-1/2″) · NW50 (2″)
- NW40 (1-1/2″) · NW50 (2″)
- Thread
- NW (KF) vacuum flange
- NW (KF) vacuum flange
- Seat
- PTFE
- PTFE
- Temperature
- −20°C to 180°C (valve)
- −20°C to 180°C (valve)
- Air supply
- 4–8 bar (60–116 psi)
- 4–8 bar (60–116 psi)
- Port
- 3-way, L-port or T-port
- 3-way, L-port or T-port
- Operation
- Manual quarter-turn lever with locking plate, ISO 5211 pad
- Rack-and-pinion actuator — double acting (DA) or spring return (SR); SR returns to preset position on air loss
Where it gets used
Every valve leak tested.
Each unit is checked for leakage before shipment.
L-port or T-port — which do I need?
An L-port connects two of the three ports at a time, so it switches flow from one branch to the other. A T-port can also connect all three, which gives you a straight-through or mixing position. Tell us which pattern you need when you order — both are made in NW40 and NW50.
What do the KF (NW) flanges connect to?
They are standard NW (ISO-KF) vacuum flanges — NW40 on the 1-1/2" valve and NW50 on the 2". You clamp them to the matching flange with a clamp and a centring ring; there are no bolts, so the valve comes off the line in seconds.
Double acting or spring return — which should I pick?
Double acting uses air for both strokes and holds its last position if air is lost. Spring return uses air one way and the spring drives the valve to a preset position on air failure. If the line has to land in a known state after air loss, pick spring return and tell us the fail direction.
Why is a lever shown on the dimension drawing?
The dimension sheets show the valve body with a lever so the port positions and flange dimensions are clear. On the pneumatic version the actuator mounts on the same ISO 5211 pad in place of the handle; the body dimensions do not change.
Can I add a solenoid valve or limit switch box?
Yes. Solenoid valves, limit switch boxes and positioners are fitted at assembly. State the accessories and your air supply — standard is 4 to 8 bar — when you request a quote.
Manual or pneumatic — which should I pick?
Manual (V-3WV) suits lines switched occasionally by an operator standing at the valve. Pneumatic suits remote operation, frequent cycling, or switching on a signal — double acting or spring return as covered above. Both share the same body, so you can mix operation types across a system.
