
Plumbing air compressor lines is as important as choosing the right air compressor, which is directly related to the stability of air supply quality and pressure. Reasonable compressor plumbing design and layout can reduce the loss of power, reduce user costs, and extend the service life of air compressor units. This article will introduce in detail how to plumb air compressor lines.
Setting up air compressor lines steps
During air compressor installation, we tend to focus on the air compressor itself, but in fact, setting up air compressor lines is also crucial. Reasonable and complete compressed air piping design can not only help the air compressor save energy, but also reduce the pressure loss of high pressure compressed air, and facilitate the future maintenance of the compressed air system.

(Compressed air piping)
Interface size to plumb air compressor lines
The exhaust port of the air compressor is equipped with a threaded connection port, such as the KDP series diesel air compressor, which can be directly connected to the compressed air piping. The interface size can be found in the factory manual of the air compressor.
However, the air compressor will vibrate when it is running. Using a hard pipe to directly connect the air compressor to the air pipeline may cause vibration of the entire compressor plumbing system, posing a threat to the safety and air-tightness of the air compressor unit. Therefore, it is recommended to choose a metal braided hose to connect the air compressor to the air pipeline system.
Choosing the right material air compressor lines
The installation of air compressor lines must comply with relevant safety standards to ensure that there are no safety hazards during the use of the equipment. The selection of air compressor lines needs to refer to factors such as air pressure, temperature, flow rate and pipeline length.
Compressed air pipelines generally use welded copper pipes, stainless steel pipes, galvanized steel pipes and seamless steel pipes for low-pressure fluid transportation. Aluminum pipes or polyethylene pipes can also be used according to design requirements.
Reasonable layout to plumb air compressor lines

(Incorrect compressed air piping)
The layout of compressed air piping should follow the principle of shortest distance and least resistance. When deciding the direction of the pipeline and selecting the diameter of the pipeline, many factors need to be considered, such as the compressed air flow rate, chemical properties, air pressure and operating environment.
And the air compressor needs to be placed in a well-ventilated place, as close to your work point as possible to reduce the length of the pipeline, which can reduce pressure loss. In addition, the length, bends and connection methods of the pipeline need to be considered to reduce the resistance of air circulation and improve the operating efficiency of the air compressor. The optimized design of the layout should be considered to facilitate maintenance and overhaul.
Support bracket to plumb air compressor lines
Use brackets to support the air compressor piping system in a place suspended on the wall so that there is no need to worry about vibration. In order to ensure the stability and safety of the pipeline, it is necessary to select suitable bracket materials and fix the bracket with expansion bolts to prevent the pipeline from loosening and deflecting, which will affect the working effect of the system.
When leading out a branch pipe from the main pipe or trunk pipe, it must be led out from the top of the main pipe or trunk pipe, connected to 1.2 to 1.5 meters above the ground, and an air distributor that equipped with a hose connector is installed, this is how to drain water from air compressor.
Connection in plumbing air compressor lines
The connection method of the air compressor lines should be selected appropriately, such as threaded connection, flange connection or welding. The pipeline diameter is not more than 50mm, and it can also be connected by threaded connection, with white painted hemp silk or raw tape as filling material; for pipelines with a diameter of more than 50mm, it is recommended to be connected by welding.
The welding operation must strictly follow the standard specifications of the relevant operating procedures, such as using pipe cutter to cut the pipe section into appropriate lengths and then clean the pipe ends. Use sandpaper or emery cloth to clean the outside of the pipes, use a deburring tool to remove the raised burrs inside the pipes, and use a propane blowtorch or welding gun to heat the welding point.
When the solder melts, capillary action will draw it into the welding point. Make sure the solder is applied around the welding point. After completion, wipe off the excess flux, as the flux will corrode the pipe over time. Let the pipes cool before installation, and the sealing effect needs to be checked before use.
Pressure regulator in plumbing air compressor lines
Minimize elbows, tees, and joints in the compressed air piping system to reduce pressure drop.
When compressed air flows in the pipe, friction resistance is generated in the straight pipe section; local resistance is generated at valves, tees, elbows, reducers, etc., resulting in air pressure loss.
You can also install a pressure regulator on air compressor lines each, so that you can control the air pressure of each branch by adjusting air compressor regulators separately without changing the settings of the entire system.
For example, most finish nailers work best at 90 psi, but a sprayer may only need 40-50 psi.
How to pressure test a gas line
In addition, after the compressed air piping system is installed, it is necessary to perform a pipeline pressure testing to ensure that the air compressor lines can withstand the pressure during normal operation of the equipment to prevent safety accidents caused by insufficient crush resistance.
The installation position and surface size of the relevant pressure and flow meters should enable the operator to clearly see the indicated pressure, and the pressure scale range should make the working pressure at 1/2-2/3 of the dial scale. The air pressure strength and air compressor maintenance air tightness test is carried out with 1.2~1.5 times the pressure of the same gas, and no leakage is qualified.
In short, during the plumbing of air compressor lines, you need to pay attention to details and strictly require yourself to ensure that the pipeline structure, connections, brackets and related safety valves are intact to ensure the stability and safety of the compressed air supply.
Compressed air piping design
There are many specifications for the main pipes of compressed air piping, the main pipe with appropriate diameter should be reasonably calculated and selected according to the user’s compressed air consumption and the length of the main pipe. Generally, the diameter of the main pipe of the air compressor is 4 inches. Control valves can be installed in sections and partitions on the main pipe to facilitate section maintenance.
When plumbing the branch line of the air compressor lines, the branch line should use the existing pipeline as much as possible, and the branch line must be connected from the top of the main line. The purpose of this design is to prevent the condensate in the main line from flowing down to the working machine through the branch line.
The compressor air outlet pipeline is preferably equipped with a one-way valve. A ball valve should be installed at the end of the main line to facilitate condensate discharge.
When plumbing the main air compressor line, the pipeline must have an inclination of 1°~2° to facilitate the discharge of condensed water in the piping. The pressure drop of the piping shall not exceed 5% of the set pressure of the compressor, so it is best to use a larger pipe diameter when piping.
When designing the pipeline installation route, the pipeline distance should be shortened as much as possible and kept straight, with fewer elbows and various valves. This design is mainly to reduce gas pressure loss.
Do not shrink the main pipeline at will. If you must shrink or enlarge the pipeline, you must use a reducer. Otherwise, mixed flow will occur at the joint, causing a large pressure loss and affecting the service life of the air compressor lines.
How to connect air dryer to compressor? If there are buffer purification facilities such as air tanks and dryers after the air compressor, the ideal piping design should be compressor + air oil separator + air receiver + front filter + air dryer + rear filter + precision filter.
In this way, the air receiver can filter out part of the condensed water, and the air receiver also has the function of lowering the temperature of the compressed air. It can reduce the load of the air dryer and the filters.
If the air consumption of the air compressor system is large and the time is very short, and the instantaneous air consumption is large, it is advisable to install an air tank as a buffer (its capacity should be greater than or equal to 20% of the maximum instantaneous air consumption ).
This can reduce the number of frequent compressor loading and unloading and the number of control element actions, which is of great benefit to maintaining the operating reliability of the compressor. In general, an air tank with a capacity of 20% of the FAD can be selected.
For compressed air with a system pressure below 1.5 MPa, the flow rate in the delivery pipe must be below 15 m/sec to avoid excessive pressure drop.
Precautions for setting up air compressor lines

(Compressor plumbing)
There are many kinds of materials for air compressor lines, mainly including high-pressure hoses, PPR pipes, galvanized pipes, seamless steel pipes, stainless steel pipes and aluminum alloy super pipes. Among them, high-pressure hoses, PPR pipes and galvanized pipes are more common in practical applications, while the latter three are relatively less used due to construction difficulty, installation efficiency and cost considerations.
High-pressure hoses are often used for the front end of compressed air mains and for connection with air compressors and post-processing equipment. Its advantages are that it can bend and deform, and is easy to install, but the cost is slightly higher, and its service life is relatively short and easy to age. Although PPR pipes are common, they are mainly used for water supply and drainage and heating. As compressed air pipelines, there are safety hazards, so they are often prohibited by safety supervision departments.
Galvanized pipes are widely used because of their thick coating and good rust resistance. It uses threaded connections, requires on-site threading operations, and takes a relatively long time to install, but has a long service life. However, after long-term use, rust impurities may be generated inside the pipe, affecting the quality of compressed air.
Stainless steel pipes have various connection methods, including welding, threading and compression. Aluminum alloy pipes are new materials that have emerged in recent years. They are light, fast, and easy to install. Stainless steel pipes and aluminum alloy pipes are stable and have a long service life, so they can ensure gas quality, but the cost is relatively high. They are mainly suitable for high-end or large enterprises such as medicine and food.
There are several points to note about the connection of air compressor pipes: first, avoid condensate backflow; second, reduce unnecessary diameter changes and elbows to reduce pressure drop; third, add valves to the air compressor outlet; fourth, reasonably set the installation position of the pipeline joint. Following these principles can ensure the stable operation of the pipeline system.
If your water lubricated screw compressor is equipped with an air receiver, a stop valve must be installed between the two. There are two purposes for this: one is to avoid affecting the operation of the entire station or other air compressors during maintenance; the other purpose is to prevent compressed air backflow failure during maintenance.

(KWI Series 100% Oil Free Water Lubricated Screw Air Compressor)
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