HIGH VACUUM ENGINEERING
Two-Step High-Vacuum Poppet Valves
Miro DAC/DLC two-step high-vacuum poppet valves support closed, partially open and fully open states, with an adjustable 0.7–3.7 mm partial opening and control documentation.
Two-step vacuum valve (DAC, DLC)
Note: For external dimensions and 3D models, please refer to the All-in-one vacuum valve.
Control method:
By controlling the voltage signals of Input1 and Input2, the valve can be in three states: closed, fully open, or partially open. The valve is normally closed, i.e., it is in a closed state when powered off.
| Input 1 | Input 2 | Valve states | Signal output | Signal indication |
| 0V | 0V | Closed | SW2 closed | LED2 on |
| 0V or 24V | 24V | Fully open | SW1 closed | LED1 on |
| 24V | 0V | Partially open | LED3 on |
Adjusting the height of the valve plate when partially open:
1.The valve enters a partially open state (i.e., Input 1 is connected to a 24V power signal, Input 2 has no input).
2.The controllable height range of the valve plate is 0.7~3.7mm, with a factory default initial height of 0.7mm (the minimum opening height can be customized to 0.4mm for the customer).
3.Holding down the up button without releasing it, LED3 flashes once every 0.5 seconds, and the valve plate rises by 0.04mm every 0.5 seconds, up to a maximum height of 3.7mm. Releasing the up button, the position information of the valve plate is stored in the valve, and can be retained after power off.
4.Holding down the down button without releasing, LED3 flashes once every 0.5 seconds, and the valve plate decreases by 0.04mm every 0.5 seconds, down to a minimum height of 0.7mm. Releasing the down button, the position information of the valve plate is stored in the valve, and can be retained after power off.
5.When the valve is connected to a driving gas source, holding down the up/down button without releasing, the valve plate will actually rise/fall by 0.04mm every 0.5 seconds; when not connected to a driving gas source, holding down the up/down button, the position information of the valve plate is stored in the valve. For example, in the first operation, the factory-set valve plate height is 0.7mm, holding down the up button for 15 seconds, the indicator light flashes a total of 30 times, then the height of the valve plate when the valve is partially open is 0.7+0.04*(15/0.5)=1.9mm.
Parameters
| Model | ISO-K DN63，KF50，KF40 |
| Body material | Aluminum A6061, Stainless steel SUS316L (weld-free integral processing, mirror polished） |
| Dynamic seal | SUS316L metal corrugated bellow |
| Driving gas | Clean compressed air or inert gas (filter precision grade ISO8573-15.4.4), 6mm inlet pipe |
| Driving gas pressure | 3.0±0.2 bar |
| External Leakage* | <1×10-11 m3•Pa/sec(1×10-10 mbar•L/sec ) |
| Internal Leakage* | <1×10-10 m3•Pa/sec(1×10-9 mbar•L/sec ) |
| Operating pressure | 1×10-9 mbar to 2000 mbar |
| Maximum forward operating pressure | 2000mbar |
| Maximum reverse operating pressure | 1200mbar |
| Sealing material | FKM |
| Air flow temperature | <250°C (with the valve body in a room temperature) |
| Solenoid voltage | 24V(±%5) |
| Magnetic switch parameters | Voltage 5~28V, leakage current 6μA, operating voltage drop about 2.5V, maximum operating current 0.5A (with short circuit protection function at 0.35A) |
*Note 1: The external leakage rate is defined as the rate at which external air permeates into the interior of the valve, mainly influenced by the quality of the sealing surface and the material of the O-rings. External leakage can be detected through external helium testing (poor quality sealing surfaces may rely on vacuum grease for temporary sealing, but vacuum grease will fail over time, leading to increased external leakage. Additionally, vacuum grease can also increase the internal leakage).
*Note 2: The internal leakage rate is influenced by the cleanliness inside the valve and the degassing performance of the internal materials. Oil and water stains can significantly increase the internal leakage rate (manifested as extremely high background levels in leak detectors). Dust, O-ring materials, and the internal surface quality of metal materials are also influencing factors, such as porous anodic oxide layers that can severely affect the internal leakage rate.