Is your air compressor unit too small to power your orbital sander or air-powered drill, or any other attachments? You do not have to spend a lot of money to buy a bigger and more powerful air compressors.
What you can do is merely add an air compressor receiver tank to your current unit without even welding it or using many tools. You only need an adjustable wrench, along with the necessary parts, and you are good to go.
Before learning how to retrofit an air receiver tank to your compressor unit, you should know the essential details about what you are dealing with.
Table of Contents
What is an air compressor receiver tank?
It is a very inherent component of a compressor unit. Its chief function is to receive and temporarily store pressurized air. It acts as a reservoir of compressed air that you can use, even while the unit is off.
It is a kind of an air receiver vessel that accommodates pressurized air for later use. It is available in many shapes and sizes, either horizontally or vertically.
Large manufacturing industries like wineries have high-pressure air receiver tanks for operating the wine presses a few times each day, during the process of manufacturing. They need it to lower their investment cost for the equipment and the plant itself.
Do you need it?
In theory, your air compressor setup can function without an air receiver tank. However, not having one in your entire system will heighten the unloading and loading cycles of the unit itself and make it work harder to its total capacity.
The air storage tanks are used mainly to hold pressurized air before entering and powering numerous equipment and going inside the pipework. It acts as buffer storage between the unit and the ever-changing demand for pressurized air.
Some units can even be mounted atop an air receiver setup, which is favored by establishments that have large expanses. This arrangement can save on the cost of installation and space.
Three chief functions of a compressor receiver tank
Storage for pressurized air
As mentioned earlier, the principal function of an air receiver surge tank is to supply temporary storage for pressurized air. Storing enables the unit to average out the peaks whenever the demand arises over the entire operational period.
Think of it as a battery for the air compressor line setup. Instead of or chemical energy storage, it is storing air, which will be used to power mechanical tools and instruments over high-demand or short outputs.
It is used to power many different devices like sandblasters, dust collector pulses, or a blowgun. You can use the air within the tank to power them, even though the compressor is off.
Having a compressed air reservoir cuts back the demand from the unit, thus extending the shelf life of a proper air compressor line setup. Using it will enable fewer horsepower units to do bigger jobs.
Heat exchanger
Whenever air is pressurized, its temperature heightens. In physics, this phenomenon is called the Pressure-Temperature Law.
It is also referred to as Gay-Lussac’s law of pressure temperature, which was discovered in the early 1800s. It is about the relationship between temperature and pressure of a mass of gas held in perpetual volume. Gay Lussac found out about this as he was making an air thermometer.
Each compressor type has different levels of air discharge, which can be as hot as two-hundred-fifty to three-hundred-fifty degrees Fahrenheit. This output is too hot for direct usage for any air-powered equipment.
Whenever air becomes hot, it carries a lot of moisture, which produces excessive air vapor. Too much of it will condense on the tools and control lines it is not found out and removed.
The condensate product should be dried before the unit is switched on for usage.
A heat exchanger is then utilized to get rid of the excessive heat caused by pressurization. A larger air tank will serve as a second-level heat exchanger. It will cause the heat to cool naturally over time as air slowly flows through the tank.
In large manufacturing plants, there is always a need for heat exchangers to support large types of machinery.
An air surge tank backs up the principal heat exchanger, thus lessening the air temperature from five to ten degrees Fahrenheit.
Why is it essential to use an air receiver in a pressurized air system?
An air compressor air receiver tank is an essential and inherent component in a compression system. Its typical size is two gals/scfm or gallon per Square Cubic Feet per Minute. If there are high demand surges, it will increase to four to ten gallons.
Whenever a unit has a twenty-five scfm rating at one-hundred PSIG, the tank should have a minimum of fifty gallons, which can reach up to two-hundred-fifty gallons if there are massive surges.
High-pressure air receiver tanks also assist in taking out water in the compressor system by enabling the air an opportunity to cool. It also lessens the pulsating effect induced by the downstream cyclical procedure or specifically by a reciprocating compressor.
They also have pressure gauges and relief valves, which are required by law for all companies that utilize compressor units. The valve is installed to be ten percent higher than the operating pressure in the system.
It is also crucial to set up a drain for the removal of liquids in the system. It can either be an automatic drain or a manual one. It is also beneficial in the long run to have an air dryer and a coalescing filter that is attached to the tanks downstream.
Benefits of compressed air receiver tanks
Cutting down the wastage of pressurized air
Once the unit is powered on for the day and cycles on and off, pressurized air will be unintentionally wasted. It will be let out during the venting process when the current air is being replaced with fresh air.
Over long periods, this will sum up to hundreds of cubic feet of pressurized air that is wasted, which could have been utilized as power for other instruments in the company.
Having a good-sized compressed air surge tank will lessen venting and cycling.
Enhancing the effectiveness of the dryer
The air receiver’s secondary function as a good heat exchanger will in the air dryer’s overall efficiency since air cools as it passes through the receiver tank.
If the air is warm, it will tend to hold more moisture than cool air. When excessive moisture will cause condensation to occur, it will turn to liquid form and pool to the bottom of the tank, and be let out through a valve.
If you let out moisture beforehand, the air receiver tank cuts down the total workload that the air dryer needs to be doing. This efficiency improvement saves the system beneficial energy.
Lowering the operating pressure
Whenever pressurized air is stored, it also permits for the unit’s operational pressure to be reduced. If there is no pressurized air storage to derive, the entire system will have to function at higher air compression to be able to satisfy peak needs.
In other words, you are forcing your compressor system to function in a maximum and heightened demand. It will eventually lead to more power usage and increased wear and tear.
As the unit is used throughout the day, with every two PSI or Pound per Square Inch that you increase, its pressure increases the need for energy by one percent. It will subsequently lead to higher energy bills.
By having an air receiver in a compressor system, it will level out those peaks. It can also satisfy intermittent pressure needs without increasing the compressed air in the system.
Types of air storage tanks
High-pressure air receiver tanks are available in a variety of shapes and sizes. You should also be aware that there are two kinds: dry and wet. Both have identical tanks, but the chief difference is the way they are installed.
Dry storage
Dry storage is situated after the air dryers to store pressurized air has undergone drying and filtering. It is no longer needed to course the compressed air via the tank for dry storage.
Its advantages:
- Whenever pressurized air is dried, it is immediately ready and accessible as it passes out of the tank and is available if a high demand for it arises.
- It also drastically cuts down on the burden and stress of the air dryer at the time of a high-demand event. Without it, wet tank air will need to get through the dryer before it will be utilized.
Even at times of high-demand events, the air dryer will run the risk of being over-capacitated as it attempts to get air at higher volumes. If the dryer would not maintain with the high demand, it will lead to unnecessary liquids in the system, and the effectiveness of dying is cut down.
Wet storage
Wet storage tanks are situated before the air drying system. Air goes through the tank in this form, passing through the compressor’s bottom port and going out the uppermost portion of the dryer.
Its advantages:
- This type will heighten the effectiveness of the air dryer by enabling excessive liquids to undergo condensation before it enters the dryer.
- It also extends the lifespan of the pre-filter component, which can be found right between the dryer and wet storage tank. Since the filtered air is dryer and cleaner, compared to the air coming directly out of the unit, hitting the filter with large amounts of liquid will be drastically lowered, coinciding with a pressure drop of the air dryer.
- Backpressure would not occur in the compressor because air filtering does not happen before going into the tank. It enables a more steadfast pressure signal to the compressor controller.
Getting the correct ratio of dry and wet pressurized air storage
For many applications, it is common sense to have a combination of dry and wet pressurized air storage. The right capacity ratio is two-thirds dry to one-third wet.
To explain this further, if you have in storage one-thousand and two-hundred gallons of pressurized air, four-hundred should be wet, and eight-hundred should be dry.
Dry compressed air is readily available upon request, and the wet tank will heighten the effectiveness of the dryer and performs as a second-level reservoir if the dry air is gone.
Storage of dry air has to be more than the wet to lessen the over-capacitating risk in the dryer during peaks in high demand.
Applications that do not have high demands and peaks do not need the dry and wet combination. It is because air will only flow through freely without having it stored.
It frequently occurs with manufacturing industries that utilize robots wherein the flow of air is uniform and inevitable.
How much air storage to you need?
Whenever a particular company stores pressurized air, its volume will depend on a few factors like:
- Airflow consistency
- Diameter of the pipework
- Capacity of the pressurized air in CFM or cubic feet per minute
- CFM peak demands in times of high need
How to calculate the requirements for pressurized air storage
Many applications follow the requirements from a capacity of three to five gallons per CFM output of the air compressor unit. For example, if your unit has a one hundred CFM rating, you will need three to five hundred gallons of storage of pressurized air.
As mentioned earlier, the one-third capacity of storage should be wet and dry storage should be two-thirds capacity.
Weather circumstances
If you opt to store your air storage tanks outside in open air, it will only be suitable if your location does not have a period of freezing conditions. Your tank will freeze and even burst, which can be dangerous and expensive to repair. It will be best to store it indoors throughout the year, wherever you and your tank are situated.
If you live in an area with moderate weather throughout the year and decide to store your tank outdoors, you have to inspect it frequently for any formulation of rust and corrosion. Once you notice it in your rank, you have to immediately address it to preserve its integrity.
If you are located in a place with reasonably cool weather with a minimal icing risk, still watch over it, even though it can produce heat on its own.
But if your weather becomes too cold, despite the tank’s ability of heat generation, it can still ice up. You can insulate it or furnish a type of ancillary heating to keep any damage from occurring.
Internal lining alternatives
There are three choices of inner linings for air storage tanks:
Stainless steel
The tank-types with stainless steel interior lining are chiefly utilized for specific applications wherein pure air is needed. It, in turn, is a costly choice but is very durable and resistant to corrosive elements to preserve the purity of the air.
Electronic manufacturing companies, hospitals, laboratories, and other establishments need highly purified air to function in their daily tasks.
Galvanized or epoxy coated
These have been epoxy-treated inner linings to lessen corrosive elements and preserve the quality of air. These have two classes:
- Galvanized- These are processed with a zinc coating that stops rust from taking shape. Zinc shields the tank’s base metal that chemically reacts with corrosive elements before reaching the base.
- Epoxy- This material is applied to the interior of the tank then cured. Once dried, it will toughen and becomes a corrosive repellant. It creates a waterproof wall between the tank’s base metal and the air.
Both types provide a protective and enduring coating of the inner linings. However, they can be costly.
Either epoxy or galvanized-coated tanks are more beneficial to maintain the purity of the air. It is because they can cut down the risk of corrosive particles coming into the airflow.
Air receiver owners may want to choose from either of the two options if they need the highest degree of purified air. It enables a long tank life and cleaner air output.
Bare steel
Most air receivers available in the market have inner linings made of bare steel and the outside coated with primer paint to repel corrosive elements. The outside is usually the same as the compressor unit to have a uniform look.
It is often utilized most of the time because it is functional as well as an inexpensive option. If lots of water will accumulate in the tank, corrosive elements might still form.
Tank accessories
All tanks must have these in order to function properly:
- Electronic auto condensate drain
- Zero air-loss condensate drains
- Pressure relief valves
- Vibration pads
Steps in adding air tank to compressor
If you have a smaller compressor unit that you use in your garage for your many DIY projects, then it is a good idea to also have an air receiver tank and link it up. The unit might not have enough power to supply some of its attachments like an impact driver or sandblaster.
You would not need to buy a bigger unit then you only need a bigger capacity tank to retrofit to your existing one without even welding it together.
1. Get the necessary parts
You do not need many attachments for your compressor. You can all get these in one trip in your local hardware shop:
- Portable and compact receiver tank will larger capacity than your compressor unit. A one-hundred PSI unit will need a one-hundred twenty-five PSI tank.
- RTV silicone adhesive
- New compressor hose, preferably in a coiled form
- NPT female brass coupler measuring ½” to 3/8”
- Another NPT female brass coupler measuring 3/8” to ¼”
- 1/4” NPT brass tee
2. Drain the compressor
Before fastening the new attachments, you need to drain any remaining liquid condensation and let out excess air in the system. This step should be standard operating procedure whenever you are using it to steer clear from the formation of corrosive elements and possible malfunction.
3. Remove the valve and attach the tee
It is the most crucial step in the process. Get an adjustable wrench to unscrew the safety valve from the compressor unit, usually located at the side.
After it is removed securely, apply the RTV adhesive surrounding the male portion. Use the wrench to screw in the tee in the area where you have taken out the valve.
Wipe any present residual material from the threaded portion of the valve, then apply RTV adhesive. Screw in the valve onto the female brass tee end.
Then fasten the new hose underneath, at the female portion of the brass tee. Check if everything is secure and tight, but avoid over-tightening the attachments.
4. Preparing the new tank
After prepping the compressor for the incoming new air tank, you need to do the same thing with the tank.
- Remove the whole assembly located at the top portion of the tank. You can keep the hose for future use, but you would not need them for the retrofitting process.
- Fasten the couplers at the part you have taken out the assembly.
- Put generous amounts of RTV adhesive to the ½” to 3/8” coupler’s male threads. Screw it in tightly with the wrench with eighty ft/lbs torque because massive pressure it holds.
- Apply RTV adhesive to the 3/8” to ¼” reducer and screw it on the previously installed coupler.
- Lastly, attach the opposite end of the hose already installed on the compressor to the reducer you have just screwed in.
Fill the tank with air
For this example, you will be using a smaller pancake compressor that has an open and close dial at the front.
- Switch the dial to closed status. It will now shut off the air going to the hose but will still go through the tee and towards the tank.
- Once you’re certain the dial is closed, switch on the compressor. You will see all the gauges will still function and not affect its functionality.
- Fill up the new tank to one hundred PSI and check on the pressure gauge.
- Once it reaches your preferred pressure capacity, shut the unit down and switch the dial back to open status.
Conclusion
Now you know everything about air compressors, receiver tanks, and combining both into one efficient piece of machinery. You have enough power stored to get any DIY project done.
