Industrial primary and specialty gases are essential to the operations of laboratories, test centers, and industrial sites. A reliable delivery system is crucial to ensure a continuous and consistent gas supply. However, amid the complexities of managing an industrial facility, the importance of these gases can be overlooked and undervalued.
Much like a plant’s electrical power grid, industrial gas distribution systems often operate unnoticed in the background, leading to the assumption they will always function as expected. As a result, when other operational demands take priority, gas distribution can be easily overlooked.
This approach is not advised. Gas distribution systems are integral to the smooth operation of a facility and should be managed accordingly. Ensuring these systems are well maintained allows operators to better control costs and enhance safety measures throughout the facility.
Understanding gas distribution systems
Gas distribution systems are complex networks of tubes, pipes, valves, and other components that transport pressurized gases from their source to where they are used (Figure 1). These systems are designed to provide easy access to gas supplies, maintain low pressure at the source, ensure an uninterrupted flow of gas, and handle various types of gases, including reactive, toxic, corrosive, or high-purity gases.
When gas distribution systems malfunction, they can pose serious risks to both workers and the environment. Leaks, for instance, can cause burns or respiratory issues, even when the gas is not inherently toxic. Over pressurization can lead to damage of downstream equipment, resulting in extended downtime, costly repairs and/or replacements. Finally, undetected toxic gas leaks can endanger workers’ health and harm the environment if not properly addressed.Even minor, unnoticed leaks can lead to substantial financial losses. For example, undetected nitrogen leaks—which typically cost 1 cent per standard cubic foot (scf)—can result in tens of thousands of dollars in losses annually. Leaks of more expensive gases such as helium—which typically cost more than $1 per scf—can escalate costs even more rapidly.
Beyond the basics: Building strong gas distribution subsystems
Gas distribution systems are only as safe as the quality of their components allows them to be. These systems are designed to reduce gas pressure from the source and ensure a consistent, stable flow to the points of use. To achieve optimal performance, four key subsystems must work seamlessly together. Specifically, an effective gas distribution system requires a source inlet connection, primary gas pressure control, automatic changeover, and point-of-use controls.
The source inlet (Figure 2) connects the high-pressure gas source to the gas distribution system. It must be designed with appropriate components, such as cylinder connections, hoses, tubing, filters, and functions for venting, purging, and pressure relief. Not all gas panels include a standard source inlet, so it is essential to verify the components and ensure that the correct cylinder connector is being used. Additionally, certain high-pressure or hazardous gases can require specialized component selection and additional design considerations.
The primary gas pressure control panel (Figure 3) is responsible for the initial pressure reduction, ensuring the source gas is delivered at the correct flow rate to the next stage of the system. This pressure reduction can be achieved using either a single pressure regulator or a dual pressure regulator setup. Determining the correct inlet and delivery pressures can be complex, as different gases require different settings. For example, ammonia is typically bottled around 116 psi (8 bar), while nitrogen can be bottled at pressures as high as 4351 psi (300 bar). In some cases, bottles that traditionally use a two-stage pressure regulator may not require one, presenting a cost-savings opportunity.
The automatic changeover panel (Figure 4) ensures an uninterrupted supply by seamlessly switching from one gas source to another. This process is managed through staggered set points on two pressure regulators, allowing the system to continue operating while the primary gas source is changed. Leveraging an automatic changeover panel can minimize waste by extracting as much as possible from each cylinder. Automating the changeover process eliminates the need for manual intervention, saving labor costs and reducing operational risks.
The point of use (Figure 5) represents the critical last stage of control in the gas distribution system. Typically equipped with a pressure regulator, gauge, and isolation valve, this subsystem allows operators to accurately and conveniently adjust gas pressure. In cases where varying line pressure between the primary gas pressure control and point of use is acceptable, a single-stage pressure regulator simplifies the system and reduces costs.For gas distribution systems to function optimally, operators must carefully select components suited to their specific applications, design the systems correctly, and commit to ongoing maintenance. While each system may have its own unique characteristics, following a few general guidelines can help streamline the design and implementation process.
Component selection and system design
Gas distribution systems are only as safe and reliable as their components. It is essential to select fittings, valves, regulators, and other parts with care, partnering with trusted suppliers who can offer expert guidance throughout the process.
Components are just one piece of the puzzle. The next step is ensuring those components will work together seamlessly. This is why systems must be carefully engineered to maximize efficiency and safety (Figure 6). To minimize the risk of leaks, engineers should limit the number of threaded connections in systems. Additionally, the system must be designed for ease of use and maintenance, with all components clearly labeled to minimize the chance of technician errors. The design should prioritize functionality, with careful consideration of tube routing and component selection to ensure cohesive operation.
Assembly, installation, and maintenance
Even the ideally designed system will not function as expected if it is not assembled and installed correctly. Once installed, the system should undergo extensive testing to ensure its overall safety and preserve its long-term performance. Operators should provide technicians with in-depth gas system-related training to avoid problems over the system’s lifespan (Figure 7). Beyond assembly and installation, technicians must be thoroughly trained in how to use and maintain the system. Without this crucial follow-up, the systems could easily develop leaks or poor operation.
To simplify the maintenance of gas distribution systems, operators should carefully consider which gas panels suit specific applications. The most effective panels position key components such as regulators on the front, allowing technicians easy access for tasks like changing filters or performing other routine maintenance.
The bottom line
Fortunately, facility operators do not have to create gas distribution systems on their own. Suppliers with expertise in these systems can guide operators toward pre-engineered, fully tested, and standardized subsystems, reducing the need for extensive training and allowing engineers to focus on customizing the systems to meet the facility’s specific requirements.
As the system is under development, bringing in third-party evaluators can provide an objective assessment and highlight opportunities for system upgrades. These experts can advise on component selection, gas panels, and system design to ensure the best fit for the facility’s needs. As emissions regulations continue to evolve, informed consultants can also recommend modifications to existing systems to ensure compliance with the latest standards (Figure 8).
Despite the critical role gas distribution systems play in industrial facilities, they often receive the least attention during design, installation, and maintenance. It is time operators prioritize these essential systems to enhance safety, efficiency, and cost-effectiveness across their operations.