Wuxi Huatong lists high-vacuum shutoff valves and ported directional valves for compressed-air circuits. The vacuum families are energized to open and have configuration-specific leak and pressure data. The K22J, K23J and K25J families differ by the number of ports and the flow paths they switch.
Models and selection data
| Model or series | Published configuration or function | Selection details |
|---|---|---|
| GZK512 | Energized-open high-vacuum valve | Listed bores include 4.5 and 6 mm. Typical connections include 1/4-inch and 3/8-inch JXR male fittings. |
| GZK712 | Energized-open high-vacuum valve | 12 or 15 mm bore. The published example is GZK712-15F-12H-DC24V. |
| K22JK-W / K22JD-WF | Two-position, two-port shutoff valves | Match the control method, de-energized state, port size and connector. |
| K23JD-W / K23JK-W | Two-position, three-port directional valves | Identify pressure, outlet and exhaust paths in the valve symbol. |
| K25J-W / K25JD-W / K25JK-W | Two-position, five-port directional valves | Select electrical or pneumatic actuation and match the valve symbol to the cylinder circuit. |
Published operating data
| Configuration | Absolute pressure or working differential | Additional published data |
|---|---|---|
| GZK512, 4.5 mm example | 1.0 × 10⁻⁶ to 0.8 × 10⁶ Pa absolute. Maximum differential 0.8 MPa. | Cv 0.60. |
| GZK512, 6 mm example | 1.0 × 10⁻⁶ to 0.3 × 10⁶ Pa absolute. Maximum differential 0.3 MPa. | Cv 1.05. |
| GZK712 | Configuration-specific differential of 0.1–0.3 MPa. | Fluid 5–55 °C. Ambient 0–55 °C. |
| GZK512 and GZK712 helium leak ratings | Catalog specifies seat and external leak rates at or below 1.0 × 10⁻⁹ Pa·m³/s He. | Confirm the applicable test conditions with the selected valve. |
Vacuum and pressure selection
Select using absolute pressure and the maximum working differential for the precise connection and bore. Record expected pressure on both sides during startup, normal operation and venting. The proof pressure, where listed, is a separate test value. For GZK712, the published allowable working differential varies from 0.1 to 0.3 MPa by configuration.
Flow and coil selection
For GZK712, the catalog lists Cv up to 4.3 in the straight direction and 4.7 in the L direction. Published coil choices are 100 or 200 V AC at 50/60 Hz and 24 V DC. Confirm the coil code and termination with the selected valve. A compressed-air directional valve also requires a check of switching state on loss of power or pilot pressure.