The Ultimate Guide to Choosing portable air receiver tank

Many air compressor applications can benefit from installing an air receiver tank. An air receiver tank increases the air available on demand, allowing for higher duty cycles and more air power.

Please visit our website for more information on this topic.

Air receiver tanks are sized in gallons, ranging from small 5- and 10-gallon tanks to massive tanks that hold thousands of gallons of air. The ideal size of an air receiver tank will depend on the air compressor and the application.

Air Receiver Tanks For Portable Air Compressors

Tanks for Reciprocating Air Compressors

Reciprocating air compressors use an air receiver tank to store compressed air and eliminate pulsation. The tool or equipment runs once the tank fills with enough air. 

In many applications, using the tool will drain the tank, and operators will need to wait for it to fill back up before using more compressed air. Properly sizing the air receiver tank with the reciprocating air compressor can help reduce interruptions and time wasted waiting for the tank to refill.

A straightforward rule for sizing an air receiver tank for a reciprocating air compressor is to take the tool with the highest CFM requirement at the required PSI, multiply that CFM requirement by 1.25 or 1.5, then round up to the closest gallon size.

Air Receiver Tank Size Per CFM Requirement

CFM x 1.25 &#; round up = minimum tank size in gallons

CFM x 1.5 &#; round up = recommended tank size in gallons

While these calculations may not completely eliminate the waiting time between tank fills, they will minimize them.

Tanks for Rotary Screw Air Compressors

For a rotary screw air compressor, many applications don&#;t require an air tank at all. Rotary screw air compressors supply a continuous air stream without interruption and pulsation.

An air receiver tank isn&#;t required if your tool requires less CFM than the air compressor produces. However, some operators may choose to use an air receiver tank to give their compressor a little boost for higher CFM tools.

For example, if an operator routinely uses a 1&#; impact wrench that requires 40 CFM but only has a 30 CFM air compressor, they may choose to add a 12-gallon air receiver tank to compensate for the difference. The task will be complete by the time the air receiver tank is empty. Operators can sometimes save money or "make do" with a smaller compressor system using this strategy.

Air Receiver Tanks For Stationary Air Compressors

Properly sizing an air receiver tank for custom stationary applications is complex and should be done by a qualified engineer. These air receiver tanks need to be sized according to the volume and pressure variations in air consumption (i.e., demand), air compressor size, pipe or hose size and length, and the control system strategy (i.e., modulation or on-off control.)

There is a commonly used formula to find the ideal air receiver tank size for a stationary air compressor system:

t = V (p1 &#; p2) / C pa

where

• V = volume of the receiver tank (cu ft)
• t = time for the receiver to go from upper to lower pressure limits (min)
• C = free air needed (SCFM)
• pa= atmosphere pressure (14.7 PSIA*)
• p1 = maximum tank pressure (PSIA)
• p2 = minimum tank pressure (PSIA)

*PSIA = Pounds Per Square Inch Absolute; pressure relative to a vacuum.

Example: Stationary Air Compressor Tank Sizing

Let&#;s look at an example using an air compressor system with the following specifications:

• mean air consumption = 20 CFM
• maximum tank pressure = 175 PSI
• minimum tank pressure = 90 PSI
• time the tool will run = 1 minute

The approximate ideal volume of the receiver tank can be calculated by modifying the sizing formula to:

V = t C pa / (p1 &#; p2)
= (1 minute) (20 CFM) (14.7 PSI) / ((175 PSI) &#; (90 PSI))
= 3.46 ft3
= 25.9 gallons

However, this formula works best for large reciprocating air compressor systems with variable airflow. Stationary rotary screw air compressor systems run at 100% duty cycle, eliminating or reducing the air receiver tank requirement if the air compressor is properly sized for the application.

Calculating Maximum Air Consumption

Identifying the maximum consumption of an air compressor system is critical when sizing an air receiver tank for a stationary compressor. Ideally, the air receiver tank will provide enough air to meet or exceed maximum consumption.

In the t = V (p1 &#; p2) / C pa formula, maximum air consumption is measured in SCFM and represented by &#;C.&#;

To calculate the maximum consumption in the system, summarize the air demand of each air tool or consumer that will be used simultaneously. The summarized consumption must then be multiplied with a utilization factor for each consuming item.

The Utilization Factor

The utilization factor is the way a tool is used and how that use affects airflow.

Let&#;s say you have an air tool like an impact wrench, which the manufacturer rates for a consumption of 20 CFM at 100 PSIG**. This wrench may be turned on for only 20 seconds at a time to tighten an individual lug nut to its required torque value.

Initially, the tool will consume the full rated 20 CFM as it tightens the lug nut against almost no resistance, but as the torque rises on the nut, the tool consumes less air until the final torque is achieved. The tool also won&#;t consume air when it isn&#;t used in between lug nuts.

The tool&#;s air consumption under load is not uniform throughout the process of torquing the lug nut, and the interval between applying the tool between individual lug nuts varies. This difference in CFM load and time interval becomes the utilization factor.

In other words, just because the tool is rated at 20 CFM, it does not mean that the tool requires the full rated CFM for each full minute nor the full minute to complete the job.

Because of this utilization factor, some air receiver tanks can meet heavy, short time demands of equipment at volumes exceeding the installed compressor&#;s supply capabilities. The minimum receiver capacity for certain applications may also be calculated, but experience and judgment are important at this point.

**PSIG = Pounds Per Square Inch in Gauge; pressure within the ambient atmospheric, measure with a gauge.

Pressure Band / Differential

The pressure band (differential) should also be considered when calculating the ideal air receiver tank size.

If the consumption process requires 100 PSIG and the compressor is set to deliver 100 PSIG, there is no storage and no buffer. Any increase in demand will result in a tank pressure drop below 100 PSIG until the compressor responds by increasing the compressed air volume to refill the tank and restore the 100 PSIG.

If the compressor is set to deliver 110 PSIG, the difference between 110 PSIG and 100 PSIG accounts for the air stored in the receiver.

If the 100 PSIG demand increases, the tank pressure can drop 10 PSIG before the minimum set pressure requirement is met. Keep in mind that the discharge piping and hoses also form part of the storage volume.

Pressure and flow controllers can be used after the receiver tank to stabilize downstream pressure to 100 PSIG and flatten demand peaks.

When Does Exact Sizing Matter?

Even with the knowledge above, properly sizing an air receiver tank is complicated and time-consuming. Operators who use straightforward tools and air compressors can default to simple CFM recommendations and choose a receiver tank using a 1 CFM to 1.25-1.5 gallon ratio. However, engineers developing complex and custom systems must determine more exact sizing requirements and need to put in the work.

You may also like:

The Parts of A Compressed Air Tank

Compressed air tanks are intricate systems comprised of several key components, each playing a crucial role in their functionality. Understanding these parts is essential for anyone involved in the compressed air industry or those looking to optimize their compressed air systems.

Cylinder Block

The cylindrical blcok serves as the primary container for compressed air. Typically constructed from carbon steel or stainless steel, its thickness varies based on the tank&#;s volume and pressure requirements.

We will also elaborate on the advantages and disadvantages of different materials below.

Tank Heads

The heads, or end caps, seal the ends of the cylinder body, maintaining the integrity of the tank.

Flanges

Flanges provide attachment points for various components, such as pipes and valves. They ensure a secure connection between different parts of the system.

Manifold of Air Intake and Out

The manifold, or piping system, facilitates the distribution of compressed air. It consists of interconnected pipes that direct the airflow to different parts of the application.

Sealing Elements

Seals and gaskets are crucial for preventing air leaks. They are strategically placed in areas prone to stress, ensuring a tight and secure enclosure.

Support Base

The support base bears the weight of the tank and maintains its stability. Usually made of steel or concrete, it prevents the tank from shifting or sliding during operation or external forces like earthquakes.

Safety Valve

The safety valve is a critical component that automatically releases excess pressure from the tank, preventing potential overpressurization and ensuring the safety of the system and its operators.

Pressure Gauge

Pressure gauges measure the internal pressure of the tank, allowing operators to monitor and control the system effectively. They provide essential data for maintaining optimal performance.

Drain Valve

The drain valve is responsible for removing accumulated moisture or contaminants from the tank. This prevents corrosion and ensures the longevity of the compressed air system.

The Role of Air Receiver Tanks in Compressed Air Systems

Compressed air systems are networks of components working together to provide a stable and reliable source of compressed air. Among these components, the air receiver tank plays a pivotal role in enhancing the efficiency and longevity of the entire system.

Buffering and Stability

The primary function of the air receiver tank is to serve as a buffer for stored air, mitigating the need for frequent loading and unloading cycles of the air compressor

This buffering effect ensures a more stable pressure within the compressed air system. By reducing the frequency of compressor cycling, the air receiver tank contributes to energy savings and prolongs the life of the compressor.

Pressure Regulation

Acting as a pressure stabilizer, the air receiver tank helps maintain a consistent pressure throughout the system. This is vital for applications that require a steady and reliable source of compressed air.

The tank absorbs excess pressure during peak demand, releasing it when the demand decreases, thereby preventing pressure fluctuations.

Moisture and Contaminant Removal

As an integral part of the post-compressor configuration, the air receiver tank plays a crucial role in improving air quality.

Moreover, it serves as a reservoir where temperature and velocity are reduced, allowing moisture and contaminants to settle. This separation process helps in removing a significant portion of liquid water, dust, and impurities from the compressed air stream.

Temperature Reduction

The air receiver tank aids in lowering the temperature of the compressed air. This is particularly beneficial as cooler air holds less moisture.

By reducing the temperature, the tank assists in minimizing the risk of condensation within the air distribution system, preventing potential corrosion issues.

Reduced Load on Air Dryers

The removal of moisture and contaminants by the air receiver tank means that downstream components, such as refrigerated air dryers, face a reduced workload.

This not only enhances the overall system efficiency but also contributes to energy savings by decreasing the demand on auxiliary equipment.

In conclusion, the air receiver tank significantly contributes to the efficiency, stability, and longevity of compressed air systems. Its role in buffering, pressure regulation, and air quality improvement showcases its importance in optimizing the overall performance of these systems.

Common Materials for Compressed Air Tanks

Compressed air tanks are vital components in a compressed air system, and the material from which they are constructed plays a crucial role in their performance and longevity. Let&#;s explore three common materials used for compressed air tanks and the associated advantages and disadvantages.

Q235B

What is Q235B?

Q235B is a carbon structural steel that is widely used in various industries. It is known for its relatively low cost and versatility.

Advantages:

Cost-Effective: Q235B is economical, making it a preferred choice for applications where cost is a significant consideration.

Weldability: It is relatively inexpensive and easy to weld, making it a popular choice for compressed air tanks.

Disadvantages:

Corrosion Susceptibility: Q235B may be prone to corrosion, especially in environments with high moisture or aggressive substances.

Lower Toughness: Compared to some other materials, Q235B may have lower toughness in certain conditions.

Q345R

What is Q345R?

Q345R is a low-alloy steel widely used in pressure vessels, including compressed air tanks.

Advantages:

High Strength: Q345R exhibits high tensile strength, making it suitable for applications demanding structural integrity.

Corrosion Resistance: It offers better resistance to corrosion compared to Q235B.

Disadvantages:

Higher Cost: Q345R is generally more expensive than Q235B due to its alloying elements.

Welding Challenges: While weldable, Q345R may require special welding procedures, adding complexity to manufacturing.

If you want to learn more, please visit our website Comair.

SUS304

What is SUS304?

SUS304 is a grade of stainless steel known for its corrosion resistance and suitability for various industrial applications.

Advantages:

Corrosion Resistance: SUS304 is highly resistant to corrosion, making it ideal for applications where exposure to moisture is a concern. This makes it suitable for compressed air tanks in environments where corrosion is a major concern

Hygienic Properties: It is often used in industries where cleanliness and hygiene are critical, such as food and pharmaceuticals.

Disadvantages:

Cost: SUS304 is more expensive than carbon steels, contributing to higher equipment costs.

Potential for Stress Corrosion Cracking: In specific conditions, such as exposure to chlorides, stress corrosion cracking may occur.

Property Q235B Q345R SUS304 Material Type Carbon Structural Steel Low-Alloy Steel Stainless Steel Advantages Cost-Effective, Weldability High Strength, Corrosion Resistance Corrosion Resistance, Hygienic Disadvantages Corrosion Susceptibility, Lower Toughness Higher Cost, Welding Challenges The Highest Cost

The above is a brief comparison of common compressed air tank materials and their characteristics. Each material has its advantages and disadvantages, and selection should be based on specific needs and operating conditions.

What is the Common Volume of Air Tank for Compressors?

The common volume of compressed air tanks varies depending on the application and the specific needs of the compressed air system. Typically, compressed air tanks are available in a wide range of sizes, from small portable tanks to large stationary units.

The common volume of these tanks ranges widely, depending on the application, system requirements, and available space. Let&#;s explore the typical volumes you might encounter:

Small-Scale Applications

Volume Range: 1 to 20 gallons (3.8 to 75.7 liters)

Common Uses: DIY projects, small workshops, pneumatic tools.

Medium-Scale Industrial Use

Volume Range: 30 to 80 gallons (113.6 to 302.8 liters)

Common Uses: Automotive shops, medium-sized manufacturing, and assembly lines.

Large-Scale Industrial and Commercial Settings

Volume Range: 100 to 500+ gallons (378.5 to .7+ liters)

Common Uses: Large manufacturing plants, heavy-duty pneumatic machinery, high-demand applications.

Choosing the right tank size involves considering factors like air demand, duty cycle, and the overall efficiency of the compressed air system.

Larger volumes provide more storage, reducing the frequency of compressor cycling and ensuring a stable air supply. However, the choice ultimately hinges on the specific requirements of the application.

here are some typical tank sizes and their corresponding volumes:

&#; 16 x 36 inches, 30 gallons, 4 cubic feet

&#; 20 x 48 inches, 60 gallons, 8 cubic feet

&#; 20 x 63 inches, 80 gallons, 10.7 cubic feet

&#; 24 x 68 inches, 120 gallons, 16 cubic feet

* The actual volume of compressed air tanks can vary widely based on the specific dimensions and design of the tank.

Choosing the Right Bar/PSI for Your Air Receiver Tank

Selecting the correct bar/PSI (Pounds per Square Inch) for your air receiver tank is a critical decision that directly impacts the efficiency and safety of your compressed air system.

Importance of Pressure Ratings

Pressure ratings indicate the maximum pressure a tank can safely handle.

Exceeding the rated PSI can lead to structural damage, leaks, or even catastrophic failure.

Matching Compressor Output

The PSI rating of the air receiver tank should be compatible with the output pressure of the compressor to ensure safe and efficient operation of the compressed air system.

A well-matched system ensures optimal performance and longevity.

Regularly check and maintain the pressure levels to prevent overloading the tank.

Application-Specific Pressure

Different applications have distinct PSI requirements.

Tools and machinery often come with recommended operating pressures; adhere to these guidelines.

Consider future expansions or changes in usage that might impact presure needs.

Safety Factors

Incorporate a safety margin when selecting working pressure.

This margin accommodates fluctuations in demand and promotes a safety buffer.

It mitigates the risk of unexpected pressure spikes.

Due to different habits, you may need to convert bar to PSI, click to check Convert bar to psi chart

Optimal Placement and Installation of Air Receiver Tanks

Proper placement and installation of air receiver tanks are important for ensuring the best performance and safety of your compressed air system.

Location Matters

Place the air receiver tank near the point of highest compressed air demand.

Minimize the distance to reduce pressure drop and ensure quick air delivery.

Avoid exposing the tank to extreme temperatures or direct sunlight.

Foundation Considerations

Install the tank on a stable foundation to prevent vibrations.

Ensure a level foundation to maintain the structural integrity of the tank.

Horizontal vs. Vertical Tanks

Horizontal tanks are often preferred for their space-saving design and lower center of gravity, making them more stable. However, they may require more floor space.

Vertical tanks are suitable for applications with limited floor space and offer better condensate drainage. However, they may have a higher center of gravity and require adequate support.

Space Constraints

Consider the available space and layout of the facility when choosing between horizontal and vertical tank configurations.

Select the tank orientation based on the specific requirements of the application, such as air flow, condensate management, and ease of installation.

Common Mistakes to Avoid

Improper Sizing

Avoid undersizing or oversizing the tank for your application.

An undersized tank can lead to frequent compressor cycling, while an oversized tank may occupy unnecessary space.

Inadequate Ventilation

Provide adequate ventilation around the tank to dissipate heat.

Poor ventilation can lead to overheating and compromise the efficiency of the compressed air system.

How to Maintain Compressed Air Tanks for Compressors?

To maintain and extend the service life of an air receiver tank, it is essential to adhere to proper maintenance techniques. Regular maintenance helps prevent issues such as rust, leaks, and other common problems.

Here are some key maintenance practices and signs that indicate immediate attention is required:

Regular Maintenance Practices

1. Inspect for Rust and Corrosion

Regularly inspect the external and internal surfaces for signs of rust or corrosion.

Address any rust spots promptly to prevent further deterioration.

2. Check for Leaks

Perform routine leak checks on connections, valves, and seams.

Leaks can lead to pressure loss and compromise the integrity of the air tank.

3. Monitor Condensate Drains

Ensure condensate drains are functioning correctly to prevent water accumulation.

Accumulated water can accelerate corrosion and compromise air quality.

4. Pressure Relief Valve Inspection

Regularly test and inspect the pressure relief valve for proper operation.

Ensure that the valve opens and closes at the specified pressure levels.

5. Protective Coating Maintenance

If your tank has a protective coating, monitor its condition.

Repair or reapply coatings as needed to prevent exposure to the elements.

Signs Your Tank Needs Attention

1. Rust or Corrosion

Any visible signs of rust or corrosion on the tank&#;s exterior or interior.

2. Unusual Sounds or Vibrations

Unusual noises or vibrations during operation can indicate internal issues.

Investigate and address these issues promptly.

3. Visible Leaks

Any visible leaks on the tank or connected components require immediate attention.

Leaks compromise the efficiency of the system and pose safety risks.

4. Reduced System Performance

If you notice a decline in compressed air system performance, inspect the air receiver.

Reduced efficiency may indicate internal issues or air leaks.

5. Rapid Cycling of Compressor

Frequent on/off cycling of the compressor may indicate an undersized or malfunctioning air receiver.

Address sizing or functionality issues promptly.

6. Pressure Fluctuations

Monitor pressure gauges for erratic or fluctuating readings.

Inconsistent pressure may suggest leaks or valve problems.

7. Physical Damage

Dents, bulges, or other physical damage to the compressed air tank&#;s structure.

Want more information on portable air receiver tank? Feel free to contact us.