Scuba tanks are an essential part of any scuba diving adventure. It is used by the divers to carry the air required for breathing underwater. The air in these tanks is filled by a scuba compressor often called breathing or scuba tank air compressor.
As a casual diver, you might never know or worry about how these scuba tanks are filled. But, serious divers and professionals, who fill their own diving tanks are fully aware of the importance of these diving compressors.
In this article, we will only cover the (Self-Contained Underwater Breathing Apparatus) scuba compressors. While there are other setups like surface-supplied diving or Hookah which are not covered.
What is a Scuba Tank Compressor /Diving Compressor
A Scuba compressor is a high-pressure compressor (normally, 3 or 4 stage reciprocating compressor) that compresses the atmospheric air in the scuba tanks to be used by divers for breathing underwater.
The air inside the tank is compressed up to 200 times (or 3000 psi) which the divers can then use by using a mouth-piece regulator in order to control the flow from the tank to the mouth.
Scuba Compressor vs. Regular Compressors
Scuba compressors are different than regular compressors in a way that these compressors are very high-pressure compressors and are able to compress more air in less space than an average regular compressor can. In order to fill the scuba tank, a high-pressure compressor is required which can compress enough air in the tank to last the duration of a dive.
In order to provide clean air for breathing, scuba tank compressors also use filters for purification. These filters clean the atmospheric air before it enters the scuba tank. It is important since the divers breathe the air directly from the scuba tank which needs to be oxygen-rich. Unclean air can be harmful and can lead to complications and even death.
How Does A Scuba Compressor Work
You already know that a scuba compressor is a high-pressure compressor. In order to achieve high-pressure, the compressor work in stages wherein each stage, the air is compressed further. Below is how a three-stage scuba compressor works. Please note that a four-stage scuba compressor also has the same working principle, but just an additional stage.
First Stage
In the first stage, the diving compressor pulls the atmospheric air into a large piston through an intake filter and compresses it to around 100 to 140 psi as it pushes it out. As the air gets hot during compression, an air cooler cools the air. The cool air then moves to the second stage.
Second Stage
The compressed air (140 psi) moves from the first stage to the second stage mid-sized piston where it is compressed further to around 800 to 1,000 psi. There is a second intercooler that cools the air.
Before going to the third stage, a moisture separator separates moisture from the air.
Third Stage
From the second stage, the air moves to a third stage smaller piston that compresses the air further up to 5,000 psi. An intercooler cools the air again and a moisture separator removes any moisture present in the air.
After this, there may be additional filters that filter the compressed air.
Things To Consider Before Buying a Scuba Compressor
Compressors for diving vary greatly in terms of the quality of air it puts out, pressure, size, filling capacity, and budget. Below are some of the factors worth considering before purchasing a scuba compressor.
Quality of Air
The first and foremost factor that you need to check is the quality of air that the scuba compressor produces. Every scuba compressor does not put out the same quality of air. Make sure to check the air quality grading of the compressor before purchasing it.
The air quality depends on the filtration and purification system of the compressor. Gas compressors require more filtration as compared to electric diving compressors, for filtering the carbon monoxide from the motor exhaust.
Oil-lubricated compressors also need special filtration to filter out the oil that might get into the compressed air.
Power Source
Scuba compressors can either run on gas, diesel, petrol or electricity. Even the same model of a compressor can be configured to run on any of these power sources. It is an important factor to consider while purchasing a diving compressor as different consumers can have different preferences when it comes to the power source.
Generally speaking, electric compressors are commonly preferred and used, just make sure you get the right wiring.
Scuba Tanks Filling Capacity/Speed
Another important factor to consider is the number of tanks that the scuba compressor can fill and the time it takes to fill one scuba tank. Some scuba compressors can fill up to two tanks within an hour while others can refill more than two at the same time.
Make sure you choose the right compressor for this purpose so that you do not lose your valuable dive time waiting for your breathing tanks to fill.
Heat, Noise, and Size
Compressors generally make a lot of noise, can generate a considerable amount of heat during compression, and can take a lot of space. Try choosing a diving compressor that is quieter, produces less heat, and is smaller in size. Soundproof and semi soundproof diving compressors are also available in the market these days.
Oil Lubricated Vs Oil-Less Scuba Compressors
Scuba compressor can either be oil-lubricated and oil-less. Oil-less compressors are a bit expensive as compared to the oil-lubricated. The basic difference between oil-less compressors and oil-lubricated compressors is that oil-less are pre-lubricated with ceramic cylinders. In the oil-lubricated scuba compressor, the consumer has to maintain the compressor oil from time to time in the compressor.
In order to provide fresh breathing air, Oil-lubricated compressors require special filters that remove any oil contaminants that go into the compressed air.
It is important to note the oil-lubricated compressors are more common to use since these scuba compressors are less expensive as compared to oil-less compressors.
Best Scuba Compressor
There are different types of scuba compressors available in the market. The one that can work best for you mostly depends on your requirements and budget. Yet there are some scuba compressors that stand out. Following are some of the best diving compressors
- HPDAVV 300bar Scuba Diving ($2,899)
- HPDMC 4500psi High Pressure Electric Air Compressor ($4,199)
- MiniDive Mini Scuba Compressor ($1,299)
FAQ (Frequently Asked Questions)
Can you use a regular air compressor for diving?
You can use regular compressors for surface-supplied diving setup or Hookah. In order to fill the scuba tanks that the divers carry, special high-pressure compressors are used.
Can you fill a scuba tank with a normal air compressor?
A normal compressor does not provide the high-pressure (3000 psi and above) that is required to fill the tanks. An average shop compressor can go up to 160 psi which is far less pressure than the required pressure. You would need a scuba compressor to fill a scuba tank.
How much air does a scuba tank need?
Scuba tanks vary in their sizes, material, and capacity. An average aluminum 80 scuba tank holds up to 80 cubic feet of air at 3000 psi. So, it’s the pressure and physical dimension of the tank that determines how much air can the scuba tank hold.
