The compressed air filter regulator is a device that combines the functions of a filter and a pressure reducer. Its construction includes a housing with a filter element (cleaning the air of moisture, oil, and dust) and a pressure regulation mechanism with a diaphragm, spring, and valve that maintains a constant, reduced output pressure. It works by centrifuging heavier contaminants and allowing air to pass through the filter element, followed by flow regulation through a valve that responds to varying output pressure.
Construction of the filter regulator
- Filter housing: Often made of aluminum, it protects the interior and is resistant to corrosion.
- Separating guide: It spins the flowing air, centrifugally precipitating heavier particles such as water, oil, and dust.
- Filter element: Removes lighter contaminants and is an integral part of the filtration process.
- Diaphragm: A key element of the reducer; the movements of the diaphragm regulate the opening and closing of the valve.
- Spring: Exerts pressure on the diaphragm and is tensioned by the adjustment knob, allowing for the setting of the desired output pressure.
- Valve (poppet, actuator): Works in conjunction with the diaphragm, opening or closing the flow of compressed air.
- Adjustment knob: An adjustable screw that increases or decreases the pressure of the spring, allowing for precise setting of the output pressure.
Operating principle
- Filtration: Compressed air enters the filter regulator, where the separating guide centrifugally removes heavier contaminants. Lighter particles are then trapped by the filter element.
- Pressure reduction: Air passes into the chamber below the diaphragm. The output pressure is regulated using a knob that tensions the spring.
- Automatic regulation: Increase in output pressure: The diaphragm rises, reducing the opening of the valve, which limits the airflow and lowers the pressure.
- Decrease in output pressure: The spring pushes the diaphragm down, opening the valve and increasing the airflow until the pressure returns to the set value.
- Maintaining stable pressure: Through this continuous process, the filter-regulator maintains a constant, reduced output pressure, regardless of fluctuations in input pressure and system demand.
Which filter regulator to choose for your installation?
To choose a filter regulator for compressed air, you need to determine the input pressure and the required output pressure, match the flow capacity (connection size), consider the operating temperature, select the housing material, and choose the level of filtration needed for the application. It is crucial that all parameters meet the needs of the receiving device and the prevailing working conditions.
Steps to choose a filter regulator:
- Determine the input and output pressure: Input pressure: this is the pressure that the regulator receives from the compressed air installation.
- Output pressure: this is the set pressure that is to be delivered to the device.
- Match the flow size and connection: Flow size: should be adjusted to the demand of the end device.
- Connection size: (e.g., 1/2", 3/4") affects the flow capacity and must match the diameter of the installation.
- Choose the appropriate material:
- Plastics: are economical.
- Brass: is a popular and versatile material.
- Stainless steel: is used in corrosive or extreme conditions.
- Decide on the level of filtration: The filter is designed to remove contaminants from compressed air. Choose a filter with the appropriate level of filtration to meet the requirements of your application and ensure air cleanliness.
- Consider the operating temperature: Check the temperature range in which the device can operate correctly. Typical regulators operate in the range of -10°C to +60°C, but there are specialized versions for extreme temperatures.
Additional tips
- Type of medium: – ensure that the regulator is suitable for compressed air.
- Weight and size: – consider the spatial constraints of the installation.
