Compressed Air Leak Management

Measuring and repairing compressed air leaks easily provides 10 to 20% lower energy costs.

Compressed air is used in factories all over the world to control machines, processes, and pneumatic equipment. It is a safe and easily available medium and can be used in all possible places via hoses and pipes. However, against the advantages there is a huge disadvantage because compressed air is one of the most expensive energy carriers. Many companies already try to reduce costs with compressed air leakage management and monitoring, but there are still many companies where significant savings can be made on compressed air costs. To start with the simple detection and repair of leaks. This immediately results in an energy gain of 10 to 20% and once expanded with compressed air monitoring and optimizations, the savings can even reach 50%!

What makes compressed air one of the most expensive energy carriers? Pascal van Putten, CEO of VPInstruments explains: “When compressing atmospheric air to a pressure of 90 to 100 psi, 75% of the electrical energy absorbed in the compressor is lost as heat. Pressure loss and leaks, among other things, ensure that the electrical efficiency of the entire compressed air installation is only 7.5 to 15%. This can be improved, and you would expect companies to do everything they can to achieve this. Yet this is not the case and every year billions of dollars in energy are wasted worldwide, simply because many companies neglect to repair leaks and to optimize the efficiency of their compressed air installation.”

Not really sustainable

Approximately 5% of all electrical energy used worldwide is converted into compressed air, in the industry this is even 10%. The generation of this enormous amount of energy contributes to CO2 emissions and climate change. For that reason alone, it is sensible and even necessary to reduce the compressed air consumption. In addition, companies simply increase their earnings if they improve the efficiency of their compressed air installation.

Leakage management: low-hanging fruit

Addressing compressed air leaks is a critical, yet often overlooked aspect of optimizing energy efficiency in industrial settings. Despite its simplicity and relatively low investment requirements, detecting and repairing leaks can yield significant cost savings. Pascal van Putten, CEO of VPInstruments, underscores the straightforward nature of leak detection and repair: “It is absolutely not complicated and does not require high investments to start detecting and repairing leaks “Let me give some examples of the costs of leaks from an installation that operates 8,760 hours/year. The system pressure is 100 PSI and the electricity costs are USD 0.10 per kWh. 10 holes of just 1/16” cost the company USD 10,500 per year. While 10 holes of 1/8”, the costs increase to USD 41,900. And in practice, we often encounter hundreds of leaks of all different sizes, and also larger than 1/8″! You can imagine what the total financial losses in that case will be.

To detect and repair the leaks you will spend a few thousand USD on a simple measuring system and parts such as gaskets, hoses, and quick couplings. We therefore call leaks the ‘low hanging fruit’ in compressed air installations. Easy to detect, easy to repair and it produces immediate financial profit. Companies often have an external agency carry out a leak audit in which all leaks found in the factory are marked with TAGs. It is not uncommon that when the auditor returns to the factory a year later, the TAGs he applied are still there. So, nothing has been done about it while the costs continue as normal!"

Prevent production downtime

Apart from the financial benefits, there is also another and perhaps even more important reason to ensure that the compressed air system functions optimally and efficiently. A reliable compressed air supply is crucial in many factories for the continuity of many production processes. The right amount of flow and pressure determine the correct operation of production machines. However, leaks contribute to pressure loss. Insufficient pressure can not only lead to machine downtime, but also affect the quality of products. Errors in packaging or inconsistent texture/taste of foods can inevitably lead to costly recalls. Not to mention the damage to your image. In addition, if pressure drop is incorrectly diagnosed as an equipment defect, there is a chance that investment in new equipment will be required. This entails (unnecessary) additional investments that could have been better utilized elsewhere. Optimizing compressed air systems not only increases energy efficiency, but also establishes the foundation for a reliable and well-performing production process.

Leak detection methods

When a hydraulic line leaks somewhere in the factory and the puddle of hydraulic fluid on the floor continues to grow, it is evident the problem is solved as quickly as possible. Not so with compressed air leaks. After all, it is ‘just air’, there is no emergency situation, they will take care of it someday. Postponement leads to cancellation and the financial and (possible) operational consequences of such a nonchalant attitude will now be clear. There are various techniques and leak detection methods to quickly and easily detect leaks in compressed air systems, ensuring minimal disruption to operations and maximum cost savings. We list a few:

• Ultrasonic leak detection. This is a commonly used method for locating compressed air leaks. Ultrasonic detectors can capture high-frequency sounds produced by air leaks and make them ‘audible’ to humans, allowing maintenance teams to accurately locate, mark and repair the source.
• Compressor monitoring. A commonly used additional method for detecting (the risk of) leaks is to carefully check/monitor the compressor. This method compares the current performance of the compressor with the achievable/expected performance according to specification. Structural deviations in a negative sense can directly indicate leaks.
• Venting test. This method measures the time it takes for a compressed air system to reach a specified pressure drop. If this is carried out periodically, a trend-based insight can be obtained into the overall system efficiency.

• Trend analysis. The use of flow meters and monitoring systems provides valuable data about possible leaks. By analyzing the measured and trended data, it becomes possible to identify areas within the plant where significant changes have occurred over time or acutely. This may be caused by (sudden) leaks. This ‘suspicious zone’ can then be specifically examined using ultrasonic measurements.
• Downtime consumption. There are still plenty of factories that do not produce during the weekend. But nevertheless, they do see their compressors kick in during the weekend. Measuring compressor power consumption during downtime is a very good indicator of the amount of leaks in a factory.

Leaks in compressed air systems can occur anywhere. They often occur at couplings and in (older) hoses. But also with (incorrectly mounted or corroded) pipes, fittings, filters, regulators and lubricators (FRLs). Leaks can also occur in production lines at control and shut-off valves, flanges, cylinder rod gaskets and thread seals.

Budget responsibility

“It is crucial that the maintenance team can independently carry out leakage repairs without the need for approval ‘from above’ every time,” Van Putten emphasizes. “After all, this has a very slowing and demotivating effect. It would be useful to introduce a guideline stating that repairing something that costs less than three to six months of energy waste can be carried out immediately and without formal approval. In addition, the savings accrued after repairs in the subsequent period can be added to the energy savings budget. This creates a self-sufficient, cyclical fund within the organization, with the result that solving leaks and further optimizing the compressed air network will make an essential contribution to increasing profits.”

Pressure reduction

After leaks have been resolved, it is important to analyze and optimize the compressed air installation in a targeted manner. With the help of permanent monitoring, for example, the current compressed air consumption is measured and monitored, and changes are signaled in a timely manner. VPInstruments has developed the real-time VPVision monitoring system that, in combination with VPFlowScope flow, pressure and temperature meters, provides the information that allows a maximum cost-effective compressed air system to be achieved. For safety reasons, a (too) high working pressure is often set, for example 7 bar. But is that necessary? Sometimes machines that require high pressure have long been replaced. By reducing the pressure in small steps and monitoring the system and machine performance full-time for correct operation, it is often possible to reduce the pressure by 14.5 to 21 PSI. Remember that every 14.5 PSI pressure reduction means a 7% reduction in energy costs, while there are no costs to try this out!

With VPVision (here with 6 flow meters) the entire compressed air network can be monitored and optimized, covering power, flow, pressure, temperature, dew point and more.

The possibilities of compressed air monitoring for your company

Are you ready to optimize your production process and save money? Our experts are happy to talk you through the possibilities and guide you every step of the way. Contact us today!