Direct acting valves switch the sealing element directly via the solenoid system. As a rule, the seal must lift off from the seat against the effective operating pressure solely by the drive. Supported by the medium pressure, a closing spring keeps the valve closed.
The function depends on the seat size, the effective operating pressure and the magnetic force.
Please note: With regard to valve designs with PTFE on the valve seat, we can only certify a leakage rate according to DIN 3230 T3, since PTFE is a hard plastic and can lead to slight leaks in the low-pressure range.
Force pilot operated valves switch on from 0 bar and can also be used where direct acting valves are used. However, they are supplied with smaller solenoids for higher pressures and larger nominal widths beyond their range of application. The drive opens a pilot hole and then lifts the sealing element from the main position directly or supported by the delta-p of the operating pressure.
The special feature of this control is that the actuator can open and close the valve without assistance from the operating pressure. In the event of a pressure difference – usually when the valve is opened – the available energy is also used.
Please note: No differential pressure is necessary for switching.
Force pilot operated valves open and close even without differential pressure and have a sealing function only in the direction of the arrow. Unless otherwise specified by us, force pilot operated valves are preferably to be installed with a stationary solenoid. For installation in a riser, we ask for prior consultation.
In order to avoid closing strokes, a closing damping is provided as a standard design from the size G5/4 or DN32.
Pilot operated valves require a pressure difference of the operating pressure for opening and closing. The minimum pressure required for this is specified as the minimum pressure in the technical data sheet. The drive here only performs a pilot control function, by means of which the main sealing element – the diaphragm or the piston – is relieved of its load. The medium pressure or the existing pressure difference raises the main seal.
With this type of control, high pressures with large nominal widths can be controlled with small solenoids.
Please note: We specify a minimum pre-pressure for our valves. The pressure difference is required in order to reliably lift or close the sealing element from the sealing surface. If the pressure difference falls below the prescribed minimum value, the proper functioning of the valves is no longer guaranteed.
All information on this page is non-binding and serves as an orientation guide. Warranty claims cannot be derived from this.