Coaxial high-pressure valves are valves with two or three connections and two switching positions. The pressure range extends from vacuum up to 400 bar. The design of these valves is similar to that of directly and externally controlled coaxial valves for up to 100 bar and also share their technical advantages, e.g. the low weight and the short, compact design; the high-pressure valves are more stable, however. The wall thicknesses for the valve housing and head tube as well as the selection of the seals and the retaining screws are specially designed for high pressure applications.
Depending on the type, the high-pressure valves are available either with a magnetic drive or with a pneumatic/hydraulic drive. The nominal width ranges from 2 to 50 mm. The bandwidth of the flow factor (KV value) extends from a few liters up to 43 m³/h. Depending on the nominal size, the valves are available in sleeves, flanges, or with special designs.
The pneumatically operated valves of the VK series in particular have an extraordinarily positive relationship between high pressure range and high flow rate due to their high switching force. Thanks to their unique coaxial design, most VK series valves already respond from a control air pressure of 3 bar, whereby the air consumption per stroke is sometimes only 1/10 of the value of products from well-known competitors. By using the coax valves, the consumption of expensive compressor air is significantly minimized. This makes these valves particularly energy-efficient. Due to the high switching force, the externally controlled valves can optionally be equipped with dirt wipers. They are also ideally suited for use with abrasive media in the high-pressure area.
The user can set the switching times as desired using the fine throttles on the pilot valves. Switching delays of up to three seconds when opening and closing are possible. This allows hydraulic pressure surges in piping systems to be prevented.
This series is typically used in gas filling stations and test benches, in compressor and hydraulic systems and in washing machines up to a maximum pressure of 400 bar. The KB 15 and KB 20 valve types have a special feature: They do not require dynamic plastic seals and can therefore also be used in cryogenic technology without concerns (low temperature down to -196 °C).
The valves can be optionally equipped e.g. with alternative pilot valves, limit switches, mounting brackets, with various plug connections such as M12x1 DESINA/VDMA, or with special PWM plugs for current reduction.
| co-ax type | orifice | connection | max. pressure range | Kv value |
|---|---|---|---|---|
A 45 |
2 - 6 mm | thread | 0 - 130 bar | 0,078 - 0,588 m³/h |
KB 15 |
2 - 8 mm | thread | 0 - 400 bar | 0,102 - 1,44 m³/h |
KB 20 |
8 - 14 mm | thread | 0 - 50 bar | 1,8 - 3,2 m³/h |
MCF-H 08 |
8 mm | thread | 0 - 160 bar | 1,2 m³/h |
VMK-H 10 |
10 mm | thread | 0 - 200 bar | 3,5 m³/h |
VMK-H / VFK-H 15 |
15 mm |
thread flange |
0 - 200 bar | 5,6 m³/h |
VMK-H / VFK-H 20 |
20 mm |
thread flange |
0 - 200 bar | 7,7 m³/h |
VMK-H / VFK-H 25 |
25 mm |
thread flange |
0 - 200 bar | 12,6 m³/h |
VMK-H / VFK-H 40 |
40 mm |
thread flange |
0 - 200 bar | 31 m³/h |
VMK-H / VFK-H 50 |
50 mm |
thread flange |
0 - 200 bar | 43 m³/h |
VMK-H / VFK-H 15 DR |
15 mm |
thread flange |
0 - 200 bar | 4,4 m³/h |
VMK-H / VFK-H 20 DR |
20 mm |
thread flange |
0 - 200 bar | 7,6 m³/h |
VMK-H / VFK-H 25 DR |
25 mm |
thread flange |
0 - 200 bar | 10,8 m³/h |
VMK-H / VFK-H 40 DR |
40 mm |
thread flange |
0 - 200 bar | 31 m³/h |
VMK-H / VFK-H 50 DR |
50 mm |
thread flange |
0 - 200 bar | 43 m³/h |
