www.hpmag.co.uk HYDRAULICS & PNEUMATICS October 2025 35 respond more precisely to shifting production requirements. There is also the broader question of system integration. Some nitrogen packages combine components from multiple suppliers, which can create support issues if something fails. A fully integrated system, designed and maintained by a single provider, offers more consistent performance and simplifies maintenance across the board. How does the new two-stage nitrogen purification system fit into this picture? A recent development in this area is the use of hydrogen to boost nitrogen purity in a secondary stage. Known as the Nitrogen Purifier through Hydrogen, or NPH, this system enables standard generators to produce gas at a lower baseline purity and then refine it to the ultra-high levels needed for laser cutting by reacting residual oxygen with hydrogen. The result is a more compact, energyefficient setup. Because the generator is working at a lower purity level, it requires less compressed air, reducing energy use by as much as 40 percent. That reduced air demand also allows for smaller compressors and lower total system costs. In space-constrained environments or facilities with limited electrical capacity, that can make a significant difference. The system also opens up opportunities for retrofit. Existing users can add the purifier to boost performance without replacing their core nitrogen generator. For fast-growing businesses investing in new machinery, that scalability is a major advantage. What do engineers often overlook when specifying nitrogen systems? One of the most common oversights is around the difference between gas purity and gas quality. Purity refers to the remaining oxygen content in the nitrogen, while quality relates to moisture, oil, and particulate contamination. These are managed separately, typically through filtration and drying. Both are important in laser cutting, but they are not interchangeable terms, and the requirements for each depend on the application. A related assumption is that nitrogen always needs to be supplied at the highest possible purity. This belief often stems from experience with bottled or bulk gas, which is typically delivered at a single, ultra-high specification regardless of actual process needs. In practice, many cutting applications do not require that level of purity, and aiming for it unnecessarily can lead to larger systems, higher air demand, and greater energy use. On-site generation allows for much greater control. By specifying the appropriate purity for the task at hand, engineers can reduce system size, improve efficiency, and lower running costs, without compromising on cut quality or process performance. Is there a risk in over specifying nitrogen purity? Yes, and it is one of the hidden inefficiencies of traditional supply models. Bottled gas suppliers tend to deliver a one-size-fits-all product, typically at very high purity levels. While this may appear to guarantee consistency, it often exceeds what the process actually requires. Over-specifying purity has two major drawbacks. First, it increases the size and complexity of any on-site system trying to match that purity. Second, it significantly raises the energy required to produce the gas. In contrast, if a user only needs 98 or 99.5 percent nitrogen, the system can be smaller, more efficient, and cheaper to run. For applications that do require ultrahigh purity, technologies such as the nitrogen purifier allow users to achieve it selectively, without scaling the entire system around it. How important is scalability in laser cutting operations? Scalability is becoming critical. The laser cutting market is growing steadily, and it is common for manufacturers to invest in new machines every few years. Each new machine increases nitrogen demand, and the ability to respond to that growth without overhauling the gas supply is a major advantage. Modular system design allows users to expand their generation capacity in line with production requirements. That might involve increasing storage, adding a booster, or introducing a purifier to support higher purity needs. Being able to adapt without starting over is especially useful for companies with limited capital budgets or those adding new machines in phases across multiple sites. Are there any recent examples of manufacturers making this transition successfully? Yes, and the experiences of those businesses help illustrate the wider shift taking place across the sector. At HBH Laser in Kettering, an investment in new fibre laser machines prompted a reassessment of nitrogen supply. The company replaced two existing generators with a single, highercapacity on-site system. This allowed them to cut a wider range of materials, including brass and copper, while maintaining a clean edge quality that supports repeatability and finish standards. The move also eliminated reliance on bottled supply, giving the business more control over costs and scheduling. KME Steelworks in Northern Ireland took a slightly different route, replacing regular nitrogen deliveries with a containerised on-site generation system. With a 24-hour production schedule and a broad customer base, continuity of supply was a key priority. The switch has delivered measurable savings on operating costs and helped reduce the site’s overall carbon footprint. The company is now exploring the use of solar power to further offset electricity usage, moving closer to a self-sufficient model. These examples reflect a wider trend. As laser cutting operations grow in scale and complexity, manufacturers are looking for solutions that offer greater flexibility, lower emissions, and more predictable long-term costs. On-site generation is increasingly being seen not just as a cost-saving measure, but as an enabler of growth and operational resilience.
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