External medium-controlled valves


  • externally controlled valves
  • Electro-pneumatic valves
  • Air-controlled valves

The lifting of the sealing element takes place with external compressed air 4 to 10 bar. In single-acting actuators, there is a compression spring for resetting to the rest position by removing the control air.

We distinguish between

  • externally controlled seat valves
  • externally controlled coaxial valves.

Externally controlled valves:

The standard functions are:

  • Closed with spring force and with medium flow
  • Closed with spring force against medium flow

In liquid-carrying pipelines, valves that close ‘against the medium flow’ are preferred for shutting off in order to minimise the notorious water hammer caused by inertia when closing. The valves are controlled via a 3/2-way pilot solenoid valve.

Remote-controlled valves are suitable for controlling gaseous, highly viscous, conditionally contaminated and aggressive media. The actuator (control) chamber is separated from the main medium.

Externally controlled coaxial valves:

The switching process with this type of control takes place almost without friction and without differential pressure. This design allows any flow direction. NO- opened with spring force is just as possible as the standard function NC- closed with spring force. The control air connection is made via a Namur interface.

The following applies to externally controlled valves:

  • Control pressure 4-10 bar is required
  • Control medium preferably air
  • Fast opening and closing time with high repeat accuracy.
  • Any installation position
  • Cost-effective
  • Suitable for position monitoring (sensor)

all externally controlled valves: https://buschjostventile.de/en/products?tagId=1&tagId=2&kindId=31&kindId=13&kindId=30