RapidAir Technical / FAQ
Below are some of the most common Rapidair Technical / FAQ we’ve received from our customers. If your question isn’t answered in these FAQs, please give us a call. We are happy to help.
Remember, care must be taken on any installation of the RapidAir or Maxline compressed air piping system. Read all installation instructions and watch installation videos before starting.
Our # 1. asked Question – What size Piping system do I need. Click here to open our chart for an easy solution.
All our systems can be adapted to any black pipe or copper system. All systems have an NPT pipe thread adapter fitting.
Choosing the correct diameter of pipe is based on how much flow rate will need to travel through the pipe. Flow rate is CFM (cubic feet per minute). While pressure does play a factor in flow rate, it is not important since most systems are set between 90 – 110 psi. Compressed air gets restricted over long distances and flow rate decreases the further you get from the air compressor.
The longer the distance the piping runs, the larger diameter of pipe you need. There is no benefit to changing the diameter of the pipe to a smaller diameter at the end of piping runs—doing that will decrease flow rate.
Use the Flow Rate Calculator to choose the correct diameter for your application.
Rapidair Products USA Flow rate calculator
The flow rate calculator says to use 3/4″ for my pipe size, but my air compressor only has a 1/2″ outlet.
The thread size of the port on your air compressor tank does not determine the pipe size for your piping system. It is calculated with the length of your piping (building size) and air compressor CFM output. Even though the port on your tank may be small, the air is only traveling through a short distance, so the restriction is minimal. Air is only restricted over a long distance with small piping.
My air compressor turns off at 175 psi, but the RapidAir home garage kit has a maximum pressure of 150 psi.
All air systems should be fed at the start of the system with a regulator unit. The regulator is typically set between 90 to 110 psi. The regulator maintains constant pressure for your air tools regardless of what the compressor turn on and shut off limits are. The regulator will keep the system pressure below the rated maximum pressure of the kit. Most air tools are rated for a maximum of 120 psi, so it’s best to keep your system pressure below that limit.
A typical installation from the air compressor starts with a jumper hose, attached to a filter regulator unit that is mounted on the wall. The air system starts at the output side of the regulator.
Water vapor is created when the compressed air temperature is high. Water vapor is the hardest to filter and separate out of the air stream. Cooler air turns the water to liquid, which makes it easy to filter. The further the filter is placed from the compressor, the cooler the air will be.
The most practical place for the filter regulator is close to the air compressor. This makes it convenient for mounting and plumbing the air system. To perform properly, It’s best to be at least 6 Mts from the compressor. But some garages are not even 6 Mts wide. While it might not perform at 100%, putting the unit next to the compressor will still work adequately.
The best air design is a loop of piping that goes all the way around the building, starting and ending at the air compressor with a tee fitting. This allows the air to travel in two directions to any air outlet and balances the air flow.
A loop is not always practical, as some building layouts just won’t allow it. We offset this by increasing the diameter of the piping to get more flow. Single air user shops typically don’t need a loop.
Pipe thread DOES NOT measure like a normal threaded bolt on the outside diameter. See this attached chart for detail
Pressure testing is essential on any installation when you will not have access to the fittings once you’re done. In wall and underground burial systems require a pressure test.
MaxLine: tubing should be covered, fittings are ok.
Like any plastic product exposed to direct sunlight, it’s best to cover or paint the tubing to extend its working life.
We keep a large inventory so we can ship your order out quickly. Typically, orders placed before 12:00 p.m. ship out the same day. Orders placed after noon ship out the next day.
Shipping is calculated at the checkout once all items are added to your cart and you are ready to purchase.
Options will be available at the checkout stage.
Rapidair and MaxLine do not interchange with common parts at a local store—they are specific to our systems.
Yes, our products are OSHA rated.
OSHA does not approve any products for safety but does rely on the manufacturer for recommendations. Since we manufacture our piping for compressed air and have verified its performance, it is allowed.
OSHA has issued guidelines that PVC plastic pipe cannot be used for compressed air piping.
There is no difference in materials for the different colors of tubing or piping that we offer. The reason for the different colors is so maintenance workers can know which gas is flowing inside the pipe.
Blue is used for Compressed air and Green is for inert gases.
MaxLine Fittings are nickel plated brass. Stainless steel is also available.
All products manufactured by RapidAir carry a one year warranty.
MaxLine: 200 psi
RapidAir Home Garage Kit: 150 psi
MaxLine -40ﹾC to 60ﹾC
RapidAir Home Garage Kit: -40ﹾC to 82ﹾC
1/2” Tubing: 100-150mm Radius
3/4” Tubing: 150-200mm Radius
1” Tubing: 250-300mm Radius
The RapidAir Home Garage kit uses push-to-connect style fittings, which designate their measurement on the outside of the tubing. The RapidAir tubing measures 1/2″ outside diameter x 3/8” inside diameter.
The MaxLine system uses compression fittings, which designate their measurement to the inside of the tubing. The MaxLine 1/2″ tubing measures 5/8” outside diameter x ½” inside diameter. For longer piping lengths, the MaxLine would offer more flow rate (CFM).
There are many different styles of quick couplers that have been developed over the years. The most popular and best for airflow are the Nitto style.
MaxLine is made to be direct buried in soil or concrete. Conduit covering is not required on the tubing. It’s best to wrap the fittings with our tape wrap to keep them from the elements. Sleeving up thru the concrete is a good practice.
The FastPipe aluminum air piping and the RapidAir Home Garage Kit are not suitable for underground burial.
Yes, all of our products can be painted.
No. PEX is single layer Cross Linked Polyethylene. MaxLine is multilayer High Density Polyethylene. PEX is pressure rated for water, which is a liquid and not compressible. There is no manufacturer of PEX who rates their product for compressed air. MaxLine is specifically designed for the pressure and to resist compressor oils.
The air we breathe is a combination of many gases, including oxygen and hydrogen. Oxygen likes to combine with other molecules. Through the compressor process, this creates H20 (water). Water vapor is created when the compressed air temperature is high. Water vapor is the hardest to filter and separate out of the air stream. Cooler air turns the water to liquid, which makes it easy to filter. All of our wall outlets come with moisture drains that can be used to purge the air system of condensed water.
There are a few ways you can remove moisture from your air system. You’ll find that the more you spend on the dryer unit, the better it will perform.
For example, a simple $80 moisture trap/filter uses centrifugal force to remove the moisture and most water vapour will pass right thru the unit.
A $400 desiccant system works well, but uses a media similar to oil dry to catch the moisture. This media needs to be changed often. These units still allow some water vapour to pass through.
A refrigerated dryer operates like a de-humidifier and is electrically powered. It lowers the dew point of the air passing through it, which removes all the moisture and passes clean, dry air through it. A typical refrigerated dryer for a 5 hp compressor would cost $1300.