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Nasta Compressed Air Services

Pumps that Make Use of Positive Displacement

Positive displacement is a fairly simple, albeit a powerful concept that is widely used for pumping mechanisms in industrial processes all over the world. The variety of applications for this type of technology are so wide, in fact, that no single type of pump uses it exclusively. The tech is used in a number of different pumps, all forming the staple for whichever industrial process it is being used in. To demonstrate this point, here are a few different types of pumps that operate through positive displacement.

Screw Pumps

A screw pump is a fairly complicated rotary pump. It uses a few screws that have opposing threads that are mounted on shafts, parallel to each other and designed to turn together. These screws are turned in their shafts during operation in order to drive fluid through the pump, affording minimal clearance between the moving parts and the casing of the pump itself.

Rotary Lobe Pumps

Because they can handle solids as well as liquids, and operate under sanitary conditions, rotary lobe pumps are often used in food processing, but they have a massive range of other industrial applications including paper production. They also offer a fairly gentle pumping action which also helps them to serve the abovementioned purposes. They operate much like gear pumps with the exception that the lobes do not make contact during operation.

Hydraulic Pumps

Hydraulic pumps, as their name would imply, converts mechanical energy into hydraulic energy by generating flow through pressure induced by the load at the pump’s outlet.  This creates a vacuum at its inlet, which forces liquid to it  and into the hydraulic system.

Contact Nasta Compressed Air for Details

Here at Nasta Compressed Air, we have a variety of pumps and air compressors for sale in Johannesburg. So give us a call today to find out about sourcing your own equipment, or visit our website to see more of what we have on offer.


Nasta Compressed Air Services

Questions About Air Compressors

Below we have a few frequently asked questions about air compressors.


What is the difference between “constant run” and “stop-start” and which one is better?


Basically, with a “constant run” air compressor, the name simply means that the motor is continuously supplying the facility with the compressed air needed. And a “stop-start” compressor is equipped with a switch which turns the machine on and off for you. If you are wondering which one is better, then that will depend on what you need the air compressor for. Typically, your smaller electric compressors will be start-stop” and the more industrial operations that require constant compressed air will make use of a “constant run” compressor.


How often does the compressors oil need to be changed?


Just like your vehicle, your compressor oil will need to be changed quite regularly. In your common rotary screw compressor, an oil change should be done at around 7000 to 8000 hours. Then for a reciprocating air compressor, you should be changing the oil around every three months. You should always check with your manufacturer first for more detailed instructions.


What about the filters? How often do they need to be changed or cleaned?


You should clean your filters on a weekly basis, it also depends on the degree of grunge and dirt in the facility. With cleaner plants, your compressor may require less frequent cleanings. You should replace your filter when you notice that it gets harder to clean or when there are holes or tears in the filter.


Can I run an electric compressor with a generator?


Yes, you can, but the more important question is, should you? With the right size generator, your compressor should be able to operate, however, you need to keep in mind that most generators tend to fluctuate and can also provide an uneven flow of power. An air compressor needs to have consistent power in order to run efficiently.


At Nasta Compressed air, we specialize in an array of air compressors. Visit our website on for more information.

Air Compressor Maintenance - Nasta Compressed Air Services

Should Your Air Compressors Be Winterized?

As the temperature starts dropping and the snow begins to fall, it’s time to inspect and look at winterizing your air compressor in order to ensure that it will be in great condition for the colder months that are coming.

Weather maintenance for your air compressor

We would recommend biannual maintenance to prepare for the extreme temperatures, One towards the end of spring and the other one towards the end of fall. During these times you will need to perform the following steps on your air compressor:

Inspect the insulation – Another sign of trouble is when the heat starts to leak from your compressor system.

Inspect the weather stripping – If there are any signs of wear and tear visible on the stripping, it should be replaced immediately.

Inspect your drains and openings for air intake – In order to ensure maximum protection from the rain and snow, the drains and openings need to be in good shape.


Check the tanks for any condensation

During the colder months your tank could accumulate moisture on the inside, and if it is left unchecked, it could freeze if the temperatures drop low enough. You will want to ensure that you inspect the tanks several times every week throughout the winter months to ensure that the condensation is not building up. If the smallest amount of moisture accumulates, you should drain it immediately. Whenever you see any moisture appear within a few days, could be a sign that something worse is happening within your compressor system.

To remove condensation as much as possible, you will want to put the drain on the receiver tank at the lowest possible angle. There are some systems that can drain the moisture automatically and are equipped with test buttons for you to see whether it is working or not.

Winterizing the condensate drains and bowls outside

One of the very common mistakes made is neglecting the outdoor drains during the winter months. When temperatures drop to freezing, you can apply heat trace tape over the exposed parts of the drain line in order to stop them from freezing.

If you aren’t planning on using your compressor in the winter months, there won’t be much need for heat tape as it won’t receive any energy without the system running. In this case, you should drain the water from the lines so that they don’t freeze.

Nasta Compressed Air Services

How Do Air Compressors Work?

Air compression is basically a twofold process where the pressure of air will rise while the volume will drop. Most commonly, compression is accomplished with reciprocating piston technology, which is what makes up the vast majority of compressors on the market.

The following parts are on all compressors with reciprocating pistons:

  • Piston
  • Crankshaft
  • Cylinder
  • Valve Head
  • Connecting Rod

Air compressors are most commonly powered by either electric or gas motors, this varies by model. At one end of the cylinder you will find the inlet and the discharge valves. They are shaped like metal flaps, and these two valves appear at opposite sides of the cylinder’s top end. The inlet sucks air in in order for the piston to compress. The compressed air will then be released through the discharge valve.

In some air compressor models, the pressure is produced with rotating compellers. However, some models that are often used by construction workers, mechanics and crafts people, usually tend to run on positive displacement, in which the air is compressed within compartments that will reduce its space. Even though some smaller air compressors could consist of merely a pump and motor, the vast majority have air tanks. The air tank is used to store amounts of air within the specified ranges of pressure until its needed to perform. In succession, the air is then used to power the pneumatic tools that are connected to the unit supply lines. Meanwhile, the motor starts repeatedly and stops to keep the pressure at the desired consistency.

With the back and forth movement, what the piston effectively does is create a vacuum. As the piston starts retracting, the space in front will get filled up with air, which is then sucked through the inlets from the outside. When the piston then extends, this air is compressed and therefore it is given the strength to push through the discharge valve, while it holds the inlet shut, and then pushes it into the tank. The pressure gains intensity as more air is sent into the tank.

At Nasta Compressed Air Services we are equipped to handle any type of repair, service or refurbishment on any compressor. For more information, visit our website on

Nasta Compressed Air Services

The history of compressed air

The very first air compressors were bellows used for metallurgy as far back as 2000 B.C. And these low pressure devices were powered by hand, foot and later on by water wheels. The air compressors main use was to fan fires that were hot enough to smelt and forge metal ores.

We still make use of bellows today; they are often hung around English fireplaces. They are used by musicians to provide compressed air to the instruments like the accordion.

Hand rulers in ancient China made use of double acting piston bellows during the third century B.C.

Inventors experimented with boiling water during the 18th century, creating large quantities of gas which cause solid containers to explode. James Watts is acknowledged worldwide for developing steam power into a useable energy source.

Compressed air was only seen as a method of transporting energy until the late 19th century.

The number of Cornish mines grew four fold between 1801 and 1862. This explosion in commerce then led the way to the Holman Brothers developing the compressed air rock drills. The Holmans Foundary which is based in Camborne was internationally acclaimed for its production of quality compressed air tools.

At this time, there were steam powered compressors used for many different applications, from locomotives that had air breaks not too different from what we might see on lorries today, to early diving experiments.

Between the year 1857 and 1870, rock drills were often used to connect France and Italy with a tunnel under Mount Cenis. In the rock drill compressed air was conveyed to a smaller cylinder that works a piston. A jumper is then connected to this piston with a rod. Air that is being forced behind the piston then impels the jumper against the rock and then it is brought back by an opening valve that allows the air through to the front of the piston.

Some cities like Birmingham, Paris and Buenos Aires had a compressed air grid system in place in the late 19th century. Initially, the purpose was to power clocks by giving off a pulse of air every minute, this then gave way to delivering power to homes etc.

Paris then had a 30-mile-wide 80 psi compressed air system that was powered by over 3000hp of compressed air equipment by 1896.

Compressed air was then mixed with gasoline in order to power rockets in the early 20th century.

The 1930’s then brought about the era of screw compressors. Heinrich Krigar from Germany first patented the technology in 1878. And this then offered a much more reliable, more efficient and quieter source of compressed air.

Nasta Compressed Air is fully equipped to handle any type of repairs, service or refurbishment on any compressor. Visit our website on for more information.

Why You Should Have a Back-up Air Compressor for Your Business

Sure it might seem like you don’t need more than one air compressor for your business, however that is not necessarily the case. This is because if your one compressor fails and stops working, you won’t be able to continue work at your business. Any business owner knows that if their employees are not able to do their work, it affects the bottom line negatively. The unfortunate truth of life is that machines are unreliable, and it is better to be prepared, hindsight is 20/20, and absolutely agonising.

Your Main Unit Is Not Enough

How a Back-up Compressor Helps You Save

Why-You-Should-Have-a-Back-up-Air-Compressor-for-Your-Business-01-By having a back-up compressor, you’re investing in the future of your business. In any situation, when you cannot do your work, it means you are not making money; you’re probably making a loss. This could be especially true if you’re in the middle of producing something such as food, and it has not been completed before the line went out, that is a loss. By having a back-up, you are also allowing for your business operations to continue in the future in times of maintenance. Spending money on a back-up could save you large losses in the future.


If you believe that getting a back-up air compressor is in the best interest of your business, visit Nasta to find the best compressor for your business. They specialise in a variety of air-compressors and they offer emergency 24 hour services for your air compressors. Visit their website to find the best solution for your needs, as well a great variety of spares to keep your compressor running.

Air Compressor Maintenance Checklist

Air-Compressor-Maintenance-Checklist-01While air compressors are built to provide you with consistent performance over a long period of time, they do require a bit of maintenance from time to time to ensure that they can do so. They can take damage from a range of sources such as weathering, ageing, dust, rust and corrosion; and those are but a few of the conditions that might undermine their effectiveness. Because of this, maintenance should never be put off, even when it seems like everything is running smoothly. It is only through regular servicing that you can extend their longevity and get the years of performance that you paid for. So to help you get it right each time, here are some guidelines on how air compressor maintenance should be approached.

Check the Air Filter

The air filter in your compressor is responsible for sifting contaminants from the air that it takes in and compresses. As the filter gets dirty, so too does the air that it uses, as well as the oil (if you are using an oil air compressor) which could lead to further damages or may simply leave your compressor working less effectively than it should. Be sure to clean your air filter regularly, and wherever it cannot be cleaned, replace it with a filter that is recognised as an appropriate air compressor product.

Inspect the Oil Levels

As it is with any motor controlled appliance, oil is responsible for keeping it running smoothly, and in the case of compressors, more cleanly. It works as a sealant, a lubricant and a cooling fluid all at the same time, which makes it important to ensure that the oil is not only free from contaminants, but is also at the appropriate levels. You may have to read your compressor’s manual to get exact measurements.

The Drain Valves and Air Tank

When air is compressed, it goes through a process by which it is cooled and heated. This causes condensation on the inside of the valves and tanks which can undermine its performance and condition. Be sure to keep your air tank and drain valves clear of moisture by draining and cleaning them regularly.

Contact Nasta Compressed Air for Details

The best way to ensure that you get the most out of your compressor is to source high quality products and parts, and to ensure that maintenance is never missed. It might even be worth your while to use the services of a maintenance technician when doing so. For more details relating to air compressors, or to find out more about pressure vessel testing, contact a representative from Nasta Compressed Air today, or visit our website for details.

What to Consider when Purchasing Industrial Air Compressors

What-to-Consider-when-Purchasing-Industrial-Air-Compressors-01Compressed air is the 4th most important source of energy along with electricity, water, and natural gas. It is one of the most popular uses in almost all industrial businesses like small and large huge workshops of waste-water treatment plants, in petroleum, cement, chemical, and mining as well as metallurgical mills—and this excludes all of the many sub-systems and other components in the entire compression system.

Compressors, primary drives, management and regulation systems, and the equipment for air processing are the most important of all the subsystems. The most contemporary industrial compressors are sold as compact units containing the compressor itself, the engine, and tons of additional devices. All of these simplify the installation process and operation facility. Additionally, this is a technology that generates compressed air as a source of energy.

Based on the usage of these compressors, you’ll see that there are numerous choices in industrial air compressors and a lot of diverse air compressors in specific industrial uses – such as rotary screw industrial air compressors, piston compressors, rotary sliding vane compressors, and centrifugal compressors.

Selecting the rotary air compressor that is right for you can be a difficult task. The right compressor can support and facilitate a lot of other tasks to a greater extent. There are a few smaller organizations who decide to use a smaller air compressor unit, but they quickly realize that this may be a mistake. Personal sized air compressor units aren’t suitable for daily use and don’t function correctly when being used for industrial use. It would be the wisest of investments to place your funds on an ideal industrial air compressor in order to save expenses and manpower in the future.

The most popular air compressors used in an industrial setting are rotary screw air compressors. They are one of the most reliable, meaning less service fees and downtime, and they have a long service life. Rotary screw air compressors are also compact in their design and have easy maintenance facilities. Business owners and managers alike tend to prefer these types of compressors.

Before you purchase your compressor, you need to analyse the space it will be occupying. Industrial air compressors that are being used in businesses that have overnight and all day operations can tend to be pretty large in size, which needs to be considered beforehand. You need to look for a reputable company like Nasta Compressed Air Services that will take the time to assess your physical space to determine which type of compressor will suit your needs best.


Nasta Compressed Air Services is fully equipped to handle any type of service, repairs or refurbishment on any compressor. We can sell any Ingersoll, Rand and ABAC compressor were we can quote a complete compressor system or help with a specific inquire. There is a comprehensive line of piston and rotary screw compressors available, from 5 to 1000 cfm, in low and high pressure models, which is designed for total accessibility and reliability. Nasta Compressed Air Services are also involved with installations of compressors and piping for compressor systems and that divines our company from others. Nasta compressors consist of a rental fleet of compressors that will help customers with the hire of a machine while there compressor are being repaired.

Which Air Compressors type is right for you?

Air Compressors - Nasta

There are many types of air compressors to choose from. Choosing the right type of air compressor is very important for your needs as it will save you money and trouble on the long run. You will learn on this page the advantages and disadvantages of the different kinds of Air Compressors.

It all depends on what you use it for! You will find here a short list of the most popular types of Air Compressors and we will discuss the pros and cons of each one, including some typical examples and ordinary uses.

The difference between these Air Compressors is both the PRESSURE and the FLOW (cubic meters per minute, or cubic feet per minute). Most common pressure is 7 to 8 bars.

Strap yourself in, because air compressors differ in many ways depending on job demands. Deciding between each option below is a matter of looking at needs, the tools being used, how many users, and budget.

An air compressor is one of the most versatile sources of power. There are different types of air compressors and each of them comes with their own offered features. An air compressor offers a lot of good benefits for their customers but at the same time, it also comes with a drawback so you better choose for the best type of air compressor that suits you perfectly.

Reciprocating air compressors are positive displacement machines, meaning that they increase the pressure of the air by reducing its volume. This means they are taking in successive volumes of air which is confined within a closed space and elevating this air to a higher pressure. The reciprocating air compressor does this by a piston within a cylinder as the compressing and displacing element.

Rotary air compressors are positive displacement compressors. Most common rotary air compressors are the single stage helical or spiral lobe oil flooded screw air compressor. These compressors consist of two rotors within a casing where the rotors compress the air internally. There are no valves. These units are basically oil cooled, where the oil seals the internal clearances.

Nasta Air Compressors are the best and most reliable company you’ll ever need for all your compressed needs.


Pressure Vessel Testing

Pressure Vessel Testing

Pressure vessel testing is a requirement, in accordance to the South African Pressure Equipment Regulations (PER), to be carried out every 3 years on any vessel with an operating pressure of 50 kPa or higher. Other than being a prerequisite under law, consistent pressure testing just makes sense. A pressure vessel can store compressed air at several times that of atmospheric pressure and can be hazardous if they are not maintained properly and tested regularly. By making sure that all air receivers or other vessels under pressure are operating according to SANS347, you are safeguarding a healthier and safer work environment.

SANS 347 is the occupational health and safety body that governs the categorisation and conventionality assessment criteria for pressure equipment and is assimilated with the PER. Pressure vessel testing is carried out in order to examine the reliability of air receivers or other pressure vessels. The test includes an internal and external check to inspect for corrosion, thickness testing and hydrostatic testing to check for leaks or cracks on a vessel. Compliance with the PER guarantees that accidents don’t happen.

Compressed air…not hot air.

Unfortunately, enterprises using compressed air are frequently taken in by the hot air of sham operators. The PER declares that any pressure testing needs to be executed under the authority of a SANAS official Authorised Inspection Authority (AIA). Compressed air that is stored in faulty receivers may become explosive and lead to serious injury or even death, as well as damage to the equipment. The question then becomes, is this risk worth the few hundred Rands saved by having the test performed by unauthorised personnel?

At Nasta Compressed Air Services, only reputable inspection authorities are used and provide pressure vessel testing that follows the Pressure Equipment Regulations and is acquiescent with all companies’ Occupational Health and Safety requests. In our over 20 years of working with air compressors and compressed air systems, Nasta Compressed Air Services has come across all sorts of duplicitous antics by fraudulent companies and individuals and realised that, in the end, it’s the client who ends up paying.

If the price of pressure testing looks too good to be true, request the service provider provides you with the CP certificate and the SANAS registration number of the Authorised Inspection Authority being used. In recent times, a company had all of the vessels on their plant tested and when they were audited, it was revealed that the company was given test certificates by a fake operator and had to have their vessels tested again at substantial cost. Accountability for the testing lies on the company and with regards to insurance or workman’s reparation claims, failure to conform can lead to non-payment and lawsuits.

Established in 1994 by Mr Jan de Jong, and operates from Alberton, Gauteng with over 27 years of experience in the compressor industry, Nasta Compressed Air Services is a fully equipped establishment that handles any type of service, repairs or refurbishment on any compressor.