What is a Pressure Operated Valve?
What is a Pressure Operated Valve?
In pressure operated valves, a neutral control medium such as e.g. air, water or nitrogen on the piston drive and thus ensures the required valve position - open or closed.
What are the benefits of Buschjost Pressure Operated Valves?
High closing forces
Short switching times
Can be used with smaller protective measures for hazardous areas
Where are they used?
Grinding/milling machine
Dosing machine
Surface treatment
Processing bulk materials
Packaging
Injection moulding
Foaming machines
Textiles
Compression moulding for chipboard coating
Printing technology
Washing systems
Cooking boiler systems
Where are they used?
These solenoid valves are suitable for applications with a battery or solar power supply
How do they work?
This type of valve is operated by pressure acting on a piston or diaphragm. The fluid is usually neutral e.g. air, water, hydraulic oil. The pressure range varies and is specified accordingly in a data table.
"Normally Closed" (N/C) valves of this type remain closed under spring pressure, when de-activated. "Normally Open" (N/O) valves of this type remain open under spring pressure, when de-activated.
When pressure is connected to port "Z" the valves open or close according to type.
A separate 3/2 pilot valve is used to supply pressure to port "Z", it is mounted either directly on the actuator or remotely.
In some cases, a 4/2 or 5/2 pilot valve will be required. The main valve position can be N/C or N/O. The basic position is determined by connecting the pilot valve output lines accordingly. (The direction of flow is usually indicated by an arrow or shown schematically on the body).
In the basic position the depressurised chamber of the actuator is open to atmosphere via the exhaust port of the "pilot valve". When the solenoid of the "pilot valve" is energised the exhaust port closes and fluid passes through the pilot valve building pressure in the chamber.
The pressure builds up under the main piston/diaphragm and via the valve spindle lifts the valve seal off the valve seat and continues until the valve is fully open.
When the pilot valve is de-energised the supply pressure is shut off and the air pressure within the chamber vents to atmosphere. The piston/diaphragm now returns under spring pressure, the valve seal covers the valve seat and the valve closes and remains closed under spring pressure.
In some versions (closing with the flow) the fluid exerts a pressure on top of the valve seal that assists the closing process.
Visit our Valves section to find out more.