Are you seeing excessive pressure drop in your compressed air system? The problem may be the layout of your compressed air pipes. The design of your compressed air distribution system can have a substantial impact on overall efficiency. An efficiently designed piping system will save energy and money and reduce wear and tear on your air compressor.
About Compressed Air Piping Systems
Your compressed air distribution system consists of a series of pipes that convey compressed air from the compressor to the point of use. Most compressed air piping systems have multiple drops along their length to support different tools, processes or production lines.
A well-designed compressed air piping system conveys air efficiently from the compressor to the endpoint with minimal pressure drop—in other words, the pressure at the end of the line is close to the pressure that is delivered by the air compressor. If your compressed air piping system is poorly designed or excessively leaky, your air compressor will have to work much harder to deliver the required pressure to equipment at the ends of the line. That will reduce the life of your air compressor. It will also cost you a lot of extra money on your energy bill.
Efficient Compressed Air Distribution System Layout: 10 Expert Tips
Implementing a few best practices in the design of your compressed air distribution system will go a long way towards reducing the pressure drop problem and extending the life of your system. These ten tips will help you improve the efficiency of your compressed air piping system.
1. Loop type distribution system – In most cases a loop type distribution system is beneficial. Loop type compressed air systems allow the air to flow in any direction to get to the demand in the path of least resistance. Typically you can multiply the capacity of straight-line piping by 1.5 for loop type compressed air distribution systems. For example: If a 2” pipe is rated for 500 CFM at 125 PSI that same length of pipe in a loop system would be rated for 750 CFM at 125 PSI.
2. Feed the loop type piping from a dry storage tank with at least one pipe size larger than the loop piping itself. Typically this is beneficial because, as mentioned above, a loop type system allows for 1.5 times the flow of a straight-lined pipe. If you feed your loop with a straight line pipe of the same size, that straight-lined pipe now becomes the bottleneck in the system. This is explained by looking at the example above; if you feed a loop of 2” pipe that is rated for 750 CFM with a straight line pipe from the tank that is also 2”, that straight line pipe can only get 500 CFM to the loop. Therefore, you are not feeding your piping loop to its fullest capacity. If you feed the loop with a 2.5” pipe that is rated for 750 CFM, then your loop can get the full 750 CFM of air that it is rated for and you have eliminated your bottleneck.
3. Eliminate quick couplings wherever possible. Quick couplings should only be used when a quick disconnect of hand tools and/or paint gun is required. Any connection to a stationary machine should be done with a hard pipe or a flexible connection with hose barbs; no quick couplings.
4. Limit the number of elbows. Try to keep piping straight and the number of elbows, tees, and other fittings to an absolute minimum. An elbow offers the equivalent pressure drop of 2-10 feet of pipe, depending on the size and type of fitting.
5. Is future expansion or adding additional demand a possibility? If so, it is much more cost-effective to plan for than now as it would be much more expensive and disruptive to upgrade the piping at a later date than it would be to install a large size initially.
6. Any leakage is unacceptable. Although there may not be any perfect system, an overnight leak-down test should not exceed 10% of the starting pressure – leak-free systems are typically much easier to arrive at with aluminum and copper piping compared to traditional threaded iron systems.
7. Avoid low points in the system that do not have a drainage point. Low points can act as a “pee” trap which will restrict airflow if it is filling with contaminants
8. All drops should have a main isolation ball valve that is reachable from ground level and a drip leg valve at the bottom for easy removal of contaminants that may have entered the system.
9. Install isolation valves, tees, and plugs throughout the main piping system so potential future expansions and modifications are easier and more cost-effective. Note: With the teseo aluminum system this may not be necessary because of the ability to tie into the system at any point while under pressure. The teseo aluminum air piping system also allows you to branch off at any point without having to do labor-intensive modifications to the header piping. Interested in Teseo?
10. Pipe drops do not need to come off the top of the main header and the main header does not need to be pitched to a corner and have a drip leg installed. Traditionally, the above layout was used because people believed it would drain moisture out of the system and prevent this moisture from getting to the point of use. The only way this layout is truly effective though is with significantly oversized compressed air piping to slow down the velocity of the air moving through the pipe. As you can imagine when compressed air is running through the pipe at a rate of 20 feet per second the compressed air is going to carry most all contaminants, including water, to wherever it is going. Instead of investing in oversized piping to slow down the velocity of air, if moisture is that much of a concern, it is more cost-effective to invest in redundant drying and filtration.
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