Technicians, engineers, and chemists have long struggled to get optimal, repeatable performance from their process analyzers. Those who design and manage these systems must be highly trained and experienced. But few colleges or universities offer sampling system design in their curricula. Having personnel onsite to determine whether a problem is caused by an analyzer or by the sampling system can take the guesswork and rework out of routine operation and maintenance, leading to greater accuracy in analytical instrumentation and cost savings for companies.
Swagelok has serviced the process analyzer market for more than 60 years, meeting all types of challenges in industries around the world. Experience has shown that understanding the design behind a sampling system is the key to detecting and correcting problems before they become costly.
“Sampling systems are considered complicated, requiring a bit of wizardry, but it’s not true,” says Mike Frost, Regional Field Engineer for Swagelok Australia. “It’s not difficult to effectively engineer a system, but you don’t know what you don’t know.”
In a typical plant scenario, Frost explains, an apprentice electrician might perform a job for several years before moving to instrumentation and learning about pressure, temperature, level, and flow. Eventually this electrician may move into Quality Assurance.
“Essentially, each technician becomes a product of where they grew up and what they experienced, but that learning can be incomplete or inconsistent,” cautions Frost. “So you create a situation, for example, where modifications have been made to a system by different techs over time.”
Eventually systems do not look—or function—as they were first built. For a Quality Assurance professional, the expectation is to know the analyzer and the basic chemistry in the plant, but a deeper understanding of sampling systems and subsystems is not required, typically. “It’s this gap in knowledge,” Frost says, “that can be harming your operation more than you think.”
Know Your Process Conditions
Maintaining timely, representative, and compatible samples is no easy task, particularly where operations are complex or experienced personnel are in short supply. To make things easier, companies should consider improving their training procedures around sampling system design, operation, and maintenance
, advises Frost.
“Does your sample represent closely enough what’s going on in the process so that you can use that information to control the process? Do you know if the fluid is compatible with the analyzer system? Is it too hot? Are the pressures too high? Is your sample already fractionated or carrying anything with it that could damage the system?
Understanding these issues—that is, the upstream processes and what’s actually happening there—is the key to maintaining a signal and a time that allows you to effectively control the process. After all, garbage in is garbage out. The better the systems are engineered, the simpler they are, the easier it is to troubleshoot them and the more reliable your results will be.”
Seek Expert Instruction
The reality in most industries is that there are thousands of poorly designed sampling systems already in the field, and new ones are installed every day. This should signal the need for real change. “Take, for example, a company that’s going through and turning on a new processing plant,” says Frost. “There’s no time to stop and figure out problems if an analyzer isn’t performing, so what happens is that part of the process goes on manual operation from day one.
“In fact, some analyzers never get used at all. If the information coming out of it is skewed, it’s either parked or considered a ‘bad actor’ and pushed down a list of higher priorities where the problem is known.
“While all companies build some inefficiency into their expectations, naturally you want to optimize plant output from the start. “One solution is to make your process analysers more reliable, and that starts with building better sampling systems.” With ongoing training and education, companies can avoid costly mistakes and common design flaws in sampling systems, adopting formulas, calculations, and engineering principles in place of approximations or past approaches (“doing what we’ve always done”).
Swagelok recommends a curriculum that teaches technicians to tell the difference between analyzer and system problems, including the core principles of sampling systems, evaluation of transport lines, location of sampling taps, preconditioning the sample, controlling flow and pressure, and sample isolation and switching.
Swagelok prepares analytical instrumentation professionals to catch mistakes before they happen and recognize common problems in sampling systems. Process Analyzer Sampling System/Subsystem (PASS) and Sample System Problem Solving and Maintenance (SSM) training instructs on fundamental and advanced practices in design, operation, and maintenance—empowering professionals to plan more accurately and maintain more carefully, with minimal error and greater system integrity. These courses are for anyone involved in the design, building, operation, or maintenance of process analyzer sampling systems.