The Pressure Control Valve: Function & Structure
All hydraulic systems are marked with an operating pressure. This must be "regulated"! There are a wide variety of products and categories in the field of pressure control valves. On our website you will get a suitable offer and all the details about pressure control valves.
What is a pressure control valve?
When it comes to hydraulic pressure control, there is no getting around the pressure control valve. In hydraulics as well as in pneumatics, the pressure control valve stands for, as the name suggests, a component that regulates pressure fluctuations and keeps them constant. Here, the inlet pressure is regulated to an outlet pressure predefined in the pressure control valve.
A directional control valve / pressure control valve from Busch Hydraulik
Principles of pressure regulation
Pressure control valves work on different principles to control the pressure in a system. Key principles include:
- Pressure reduction: Reduces the inlet pressure to a desired outlet pressure.
- Pressure limit: Limits the system pressure to a maximum value.
- Pressure compensation: Keeps pressure constant, regardless of changes in flow or load.
Function of a pressure regulating valve
Pressure control valves are mainly used to counteract pressure spikes. The set pressure remains constant, regardless of whether the incoming pressure is above or below the target pressure.
Applications of Pressure Control Valves
Hydraulic applications
Pressure control valves are indispensable in many hydraulic systems:
- Mobile hydraulics: They are used in construction machinery, agricultural equipment and commercial vehicles.
- Industrial hydraulics: Here they are used to control industrial plants, presses and hoists.
- Machine tools: They provide precise pressure control in CNC machines, milling machines and lathes.
Pneumatic applications
Pressure control valves also play an important role in pneumatic systems:
- Compressed air supply: They regulate the pressure in compressed air networks and provide uniform, stable pressure for tools and machines.
- Pneumatic controls: In automated processes and production lines, they enable precise control of actuators, cylinders and valves.
Which pressure is the right one?
There are 2 types of marking for hydraulic and pneumatic systems. In physics, the pressure (bar) is given as a formula symbol in "p" and "l/min" as the flow. You can find content regarding the appropriate print in the enclosed article of our products.
Hydraulic components such as valves provide information about the pressure to be applied to them. The manufacturer prescribes which is the optimal resolution for the respective devices. In order to protect the corresponding components or to be able to guarantee their function completely, pressure control valves are used.
Assembly
During installation, care must be taken to switch off the system and all associated consumers. For your own safety, installation is completely pressureless. The supply lines must be clean and wear-free!
First, bring the pressure control valve into the installation position – the flow direction must be observed! Arrows or numbers are used as orientation here, which indicate the entrance and exit. The enclosed seals are then used in accordance with the regulations.
After all screw connections have been tightened and the lines can be opened again, the next step is to check the valve for leaks and leaks, as these can affect the inlet and outlet pressure.
Attitude
An arrow indicates the direction in which the pressure should be adjusted. The pressure gauge indicates how high the output pressure should be regulated. It can either be operated by hand (turned) or with a tool – in hydraulics, an external hexagon wrench is usually used.
The pressure gauge shows the pressure
Commissioning – Pressure Control Valves
Pressure valves are always supplied with a relaxed spring. This means that no defined presets have been made at the factory. First, loosen the safety nut of the adjusting screw. Then turn the adjusting screw clockwise – a look at the pressure gauge reveals the pressure in the rear chamber.
Once the pressure has been set, the safety nut must be screwed tightly – this prevents the adjusting screw from loosening itself due to vibration and movement.
Maintenance
The service is not to be sneezed at with such complex components! In order to be able to maintain properly, it is best to follow the manufacturer's instructions. In principle, the maintenance of valves can be defined in intervals.
Once a week: should you check the general function – does the valve maintain the set outlet pressure?
Once a month: do you carry out a visual inspection – are the pipe connections and the valve housing tight?
2 times a year: should you check the movement of the spindle – does the adjusting screw rise by itself without a lock nut?
Once a year: carry out preventive maintenance – this includes dismantling the valve to check for contamination or damage to the diaphragm
Beware of the risk of crushing! Take the valve out of operation for cleaning!
The main types of pressure control valves
Simple pressure control valves are screwed to hydraulic pipelines – ring lines or fittings. If you want to regulate fluctuating volume flow or provide a valve in a control block, proportional or seated control valves are used.
Proportional pressure control technology
In some cases, a simple pressure control technology is not enough to guarantee functions perfectly. For example, if you equip a piston with a throttle, the volume flow also changes!
If the load increases at a constant extension speed or speed of a hydraulic motor, flow control valves must be used. A flow control valve can keep the volume flow constant even with different pressure drops.
Here you control by voltage supply, which brings the pressure control valve into the appropriate position by means of the magnetic current.
Pressure control valve as seat valve
Pressure control valves can not only be used on ring lines! There are also usually designated connections for internal components. A screw-in valve is used for this purpose.