Understanding Your Pneumatic System Components

Industry relies upon pneumatic systems to power tools, automated equipment and machines throughout the plant. Having a basic understanding of pneumatic system components goes a long way toward maintaining efficient operation of these essential systems.

As your compressed air partner, JHFOSTER has experts ready to help you design a pneumatic system that provides reliable, safe and effective performance.

What is a Pneumatic System?

Pneumatic systems use compressed air to create a force that moves a load. Depending on the application, typical motions might include pushing, pulling, lifting or holding.

Simple, economical and reliable pneumatic systems move cylinders, grippers, motors or other parts on all types of automated machinery, including:

• Fabrication equipment
• Packing machinery
• Paint spraying equipment
• Filling equipment
• Material handling machines
• Presses
• Air-powered tools

The Advantages of Pneumatic Systems

There’s a reason that pneumatic systems are widely used throughout industry – they provide significant advantages, including:

Cost efficiency: Ambient air is free, components are inexpensive and maintenance requirements are low.

Simple design: Few components and simple operating principle reduce complexities.

Reliability: The simple design and durable components make pneumatics a reliable choice for challenging industrial environments.

Safety: Pneumatics can be used safely in explosive environments.

Environmentally friendly: There are no hydraulic fluid leaks to contain or clean up.

Flexibility: Air pressure and flow can be adjusted to suit the application.

Pneumatic System Components

The consistency and quality of your compressed air are critical to the performance of air-powered equipment. To ensure efficiency, systems should be designed with these essential components.

Air Filter: When air is drawn into the compressor during intake, it likely carries contaminants, such as dust, dirt and pollen. Filters remove these impurities from the air before it enters the compressor and pneumatic system.

Air Compressor: The air compressor is the device that pressurizes the air. It draws air into a chamber and compresses it into a much smaller space, creating enough force to generate motion. Compressed air is stored for use until needed.

Air Cooler/Dryer: Cool, dry air is the key to high-performing pneumatic systems. As it leaves the compressor, warm compressed air is cooled by an air cooler. An air dryer will remove any residual moisture from the compressed air.

Air Storage Tank: The air storage tank stores the produced, cooled and dried air that leaves the air compressor, ensuring a steady supply of compressed air.

FRL (filter, regulator, lubricator) Unit: While the filters, air regulators and lubricator can be separate components, they are often considered one unit in pneumatic systems. The point-of-use FRL offers several functions. First, it filters remaining moisture or contaminants from the air as it leaves the distribution system. The regulator regulates the pressure so that it does not exceed limits and reduces inefficiencies caused by excess pressure. When required, the last stage of the FRL provides light lubrication to pneumatic control valves and actuators, increasing efficiency and equipment lifespan.

Control Valve: Control valves control the direction and amount of air entering the actuators.

Actuators: Actuators convert the energy of the pressurized air into mechanical movement. Linear actuators provide straight-line or linear motion, while rotatory actuators provide rotary or circular motion.

Pneumatic System Operating Principle

Pneumatic systems operate in seven steps:

Step 1: Before air is drawn into the compressor, it passes through the air filter where contaminants are removed.

Step 2: The air is sent into the compressor where it is pressurized.

Step 3: The still-warm compressed air enters the air cooler, wet storage tank, line filtration, and/or air dryer where it is cooled and dried.

Step 4: Treated compressed air is stored in the dry air storage tank, often including a main line pressure regulator, until it is needed.

Step 5: Once in demand, the compressed air enters the point-of-use FRL unit, which filters the air, regulates the pressure and lubricates the air.

Step 6: Control valves send the compressed air to the equipment

Step 7: Compressed air enters the actuator, which converts the pressurized air into motion that drives the equipment.

How to Choose and Size Pneumatic Components

Bigger isn’t always better. Precise sizing of pneumatic components is key to optimal performance.

Sizing Your Air Compressor

Undersized air compressors will not provide enough pressure or airflow to equipment, reducing performance. An oversized compressor will consume too much energy. Air compressors should be selected based on airflow and pressure requirements, as well as the required duty cycle. More information on sizing an air compressor is available here.

Sizing Pneumatic Valves

To prevent sluggish performance, pneumatic valve sizing must match the required flow rate of the actuator. Determining valve sizing can be complex, but the experts at JHFOSTER can help evaluate your system to ensure proper valve sizing. Additional information on pneumatic valve sizing and calculations are also available in our blog.

Understanding Pneumatic Valve Variations

Pneumatic valves, also called directional control valves, come in multiple port configurations with each port assigned a specific function. For example, a three-way directional control valve will have one port connected to the pressurized airflow, another port connected to the actuator and a third port for exhaust.

Common pneumatic valve types include:

• 2-Way: These offer one inlet and one outlet to allow or stop flow.
• 3-Way: These valves contain an additional exhaust port to vent pressure from the outlet when the inlet is blocked.
• 4-Way: With one inlet, one exhaust and two outlet ports, 4-way valves are commonly used to control double-acting cylinders.
• 4-Way 5-Port Valves: Five-port valves are an evolution of 4-way valves, typically with one pressure inlet, two outlets to the device and two exhaust ports.
• 5/2 Configuration: This configuration offers five ports and two positions, such as extend and retract.
• 5/3 Configuration: This configuration has five ports and three positions. The third or center position (all ports blocked, center exhaust, center pressure) permits an actuator to stop mid-stroke.

Troubleshooting Pressure Drops

Pressure drop, a loss of energy caused by friction or leaks, is the most common pneumatic system failure. Pressure drops force the air compressor to work harder to produce the required pressure, resulting in increased compressor wear and energy consumption. Point-of-use equipment will also underperform if it does not receive adequate pressure. This blog explains pressure drops and how to avoid them.

Troubleshooting Common Causes of Pressure Drops

If you experience pressure drop, check the following:

Filters: Clogged filters can block airflow, resulting in a pressure drop. Inspect filters and replace them if needed. Routine filter element replacement typically follows a schedule based on hourly usage as recommended in your unit’s manual, but very dusty environments may require more frequent changes to ensure optimal airflow and pressure. For more on filter maintenance, check out this blog.

Piping: If your air delivery piping is too small for your required airflow, it will create friction that slows the air down. A delivery system with many turns or sharp angles could be another culprit. For more on designing a high-performance air delivery system, read this blog.

Leaks: Air leaks in your pneumatic system may also cause a pressure drop. Leaks are common in couplings, hoses, fittings and joints. Finding and fixing leaks will reduce pressure drop and increase the overall performance and efficiency of the system. This blog details the process of finding and fixing leaks.

Partner with the Pneumatic System Experts at JHFOSTER

Pneumatic systems provide simple, efficient and cost-effective power for your operation. As your compressed air partner, the professionals at JHFOSTER can evaluate your application, design and integrate a system with the right components and provide the service and support to ensure your pneumatic system provides efficiency for years to come. Request a quote today.