Common Challenges with Process Sampling Systems
Phil Harris and Tony Waters, Sampling System Experts & Instructors
Any analyzer engineer will tell you that process sampling systems can be challenging to operate correctly. If any components within your sampling system were to fail, your facility might experience downtime, potential economic loss and perhaps even major safety concerns. Managing a sampling system can be a difficult task for even the most experienced engineer. Below, we share some of the most common sampling system challenges we’ve seen in our combined 80 years of experience.
Recurring Analyzer Maintenance Issues
In many of the sampling system installations Swagelok field engineers encounter, customers experience recurring issues related to process analyzer maintenance. These problems require maintenance technicians to spend a great deal of time working on the analyzer --sometimes even in the middle of the night or on a weekend.
Plants can improve the reliability of their analyzers by auditing them often and eliminating simple mistakes from their sample system installations. We have seen significant errors like reversed check valves blocking the sample flow or a fast loop flowing backwards that are easy to remedy.
Sampling System Design Issues
Improper sampling system design can lead to a host of issues throughout the lifetime of the system. One complication that Swagelok field engineers continually come across is inadequate fluid line heating. A line may be unheated when it’s supposed to be heated, or the opposite is true — the line is so hot that the sample within polymerizes or decomposes. Another issue that engineers often find is that there are liquids where they don’t belong, thus causing damage to the surrounding equipment in contact with the unwelcome liquid.
Novice design engineers can make mistakes that are implemented into the final design of the sampling system because the reviewing engineers are just as inexperienced. To overcome knowledge gaps in sampling system design, engineers and technicians alike are encouraged to seek qualified training programs that address the complexities and fundamental design principles related to these systems. Swagelok offers process sampling system training courses for different experience levels and interests, each taught by industry experts with decades of experience.
A process analyzer can appear to be functioning properly but be largely ineffective. For instance, the time delay that some of our field engineers discover can be quite lengthy. This delay could add hours, or even days, before operators receive a measurement. Remember, a one-minute response time is the industry standard in sampling systems. While the measurement proves that the analyzer is operating, delayed information is completely useless; it is not representative of the real-time product within your system.
A poor estimate or wrong assumption about time delay can result in unsatisfactory process control. The only way to reduce this delay is by modifying the system design. Some simple sampling system design modifications can bring a large delay down to the one-minute industry standard if properly executed.
Why Bring in an Expert Evaluator?
A fresh set of eyes on your process analyzer sampling system could solve an issue your plant has endured for years, sometimes even decades. Swagelok field engineers have even reported getting a customer’s analyzer to work for the first-time ever, after system evaluation and improvement.
An expert sampling system evaluator will be able to look inside your entire system and see exactly where samples are coming from, and what may have happened to them before they reached the process analyzer. Simple alterations, like eliminating deadlegs, can speed up your analyzer response and remove potential contamination. Swagelok offers evaluation and advisory services to help improve analyzer system operation, providing solutions customized to your specific applications.
For more help solving your sampling system challenges, contact your local Swagelok Sales and Service Center.