Improving the Safety and Efficiency of Gas Distribution Systems
Many laboratories, test centers, and industrial sites rely on the safe and continuous supply of primary and specialty gases to support critical processes. For lab and reliability managers, engineers, and operations staff, optimizing the integrity of these gas distribution systems is vital to ensuring a productive business.
Inefficient gas bottle usage or undetected leaks can lead to extra spending if these issues go unresolved. Other times, it can be hard to diagnose problems without a line drawing mapping the system. Meanwhile, when tests must be repeated or results are inaccurate, the outcome is often an untimely setback or costly delay.
Valuable knowledge might also be lost when experts retire or relocate, leaving gaps in the understanding of gas distribution systems. Many companies benefit from the experience and trained eye of a professional consultant who can identify areas for improvement by reevaluating gas panels from the ground up. Often, a new point of view can reveal trouble spots that are overlooked because they don’t attract attention. Benchmarking systems provides an opportunity to set assumptions aside (e.g., “it’s always been that way” or “we’ve never had a problem”) and carefully investigate all aspects of the design.
Systems and Savings Advice
Gas distribution systems are built around one or a series of pressure regulation steps and are typically composed of four subsystems: source inlet connection, primary gas pressure control, automatic changeover, and point-of-use.
- The source inlet connects the high-pressure gas source to the gas distribution system. Importantly, the inlet must be built with appropriate cylinder connections, hoses, tubing, filters, vent, purge, and relief functions. Some gas panels may not include a standard source inlet—always verify componentry and that panels will use the correct cylinder connector. Some high-pressure and/or hazardous gases (including oxygen) also require the use of special application hoses.
- The primary gas pressure control completes the first pressure reduction and ensures the source gas is delivered at the correct flow rate to the next stage of the system. Reduction is accomplished with either a single pressure regulator or through a dual pressure regulator arrangement. Pinpointing correct inlet and delivery pressures is challenging. It is important, for example, to factor for differences between media, such as ammonia that is bottled around 116 psi (8 bar) and nitrogen that can be bottled at 4351 psi (300 bar). Meanwhile, many bottles that use a two-stage pressure regulator may not, in fact, require one. This can be a cost-saving opportunity.
- The automatic changeover seamlessly switches from one gas source to another to ensure an uninterrupted supply. This is performed through staggered set points of two pressure regulators, allowing the system to continue to operate as the primary gas source is changed. It is advisable to look for a solution that allows for varying changeover pressures to get the most use from gas bottles.
- The point-of-use provides the critical last stage of control. Typically having a pressure regulator, gauge, and isolation valve, these subsystems give operators a convenient and accurate method for adjusting pressure. Where varying line pressure between the primary gas pressure control and point-of-use is acceptable, a single-stage pressure regulator might be used to reduce cost and complexity.
Not all gas distribution systems use the same quality components, and some are better labeled than others for operator safety. At times, panels can lack important features that support serviceability. A common issue for many owners is pressure regulator creep, identified by a rise of outlet pressure even when there is no system flow. This can negatively impact downstream processes. Swagelok field engineers can help identify causes and solutions to issues like regulator creep as part of a comprehensive evaluation and advisory service.
Importantly, gas distribution system design must allow for easy component replacement. By using more compression fittings in place of threaded connections, it is possible to minimize the time required to access components for maintenance—that is, individual parts are easy to remove in-line while leaving others in place. This creates the flexibility to change components rather than replace panels and helps technicians work efficiently. It also reduces the risk for parts to be compromised (unscrewing and reinstalling a relief valve, for instance, invites potential thread damage, which can result in dangerous and costly leakage).
A Specialist Can Add Value
Professional pressure control advisory services can provide critical analysis to identify system upgrades, inform regulator sizing and selection, and guide the design and assembly of engineered solutions. A consultant who is familiar with specific gas delivery challenges can offer:
- Suggestions for how existing systems can be modified to meet new requirements (often, old panels are disposed of unnecessarily—be sure to ask about solutions designed to last)
- Options for easy procurement of gas panels built and tested by experienced installers working in suitable facilities (potentially reducing time, cost, and risk as opposed to panels assembled on-site by less-practiced installers)
- An unbiased recommendation that puts the needs of the business first (an advisor having no prior ownership stake in the system or its operation can offer impartial advice)
An advisor can also help ensure that toxic and flammable gases are delivered safely with minimal loss, that panels provide clear instruction, and that systems are easy to operate and troubleshoot.
If you are unsure of the effectiveness of your gas distribution system, are working to refit your space with a new system, or are replacing bottles before they are empty, consider reaching out to a pressure control specialist who can help correct problems and maximize your investment.