There are many things to consider with flow measurement technology, including prioritizing safety features for hazardous processes and remote locations. Additionally, the proper instrumentation prevents leaks and environmental incidents while supporting efficiency and operations. To help us better understand all things involved, Chemical Processing spoke with David Wright, global product manager at Emerson. In his role, he supports flow measurement products in a variety of industries, including oil and gas, chemical, refining and food and beverage.
Here is an edited version of that conversation.
Traci: Well, let's kick it off here from the basics. When selecting flow measurement technology, what should we be looking for in order to maintain plant safety, especially in the cases of hazardous processes and hard-to-access areas?
David: You need to look at the flow instrument itself. There's a huge variety of options — Coriolis, Mag Vortex, DP Flow, ultrasonic — and you want to get the best fit for your application. Consider accuracy and reliability for process control, how durable the primary is, and what cleaning mechanisms exist for difficult fluids. For hard-to-access areas, look at remote electronics or configuration options. At Emerson, we have Bluetooth connectivity, which removes the need for technicians to set up scaffolding or physically climb to connect to a device. They can do it from a safe distance while maintaining connectivity and understanding what's going on with the process.
Traci: You mentioned being able to access from a safe distance, and I want to talk a little bit more about some of the challenges to be aware of and also talking about integrating with existing plant control systems.
David: Given the size of most chemical plants — we're talking acres of space — and the fact that many have been around for decades, implementing a plant control system is a long-term choice. There's very little room to pivot to a new system within a 10-year period. When you're choosing instrumentation, you need to find one that fits the correct infrastructure. Understand what digital protocols your system needs — HART, Modbus, Fieldbus — and make sure you're buying the correct protocols. Power and communication wiring is also important. Instrumentation typically runs on two, four or nine wires, or wireless, but you'll likely need to use existing conduit, especially if you're replacing instrumentation. Also look at scalability with output channels and what diagnostics are offered by the device and whether they can be read by the system.
Traci: What issues can arise in plants that can impact site and environmental safety?
David: Safety is the No. 1 concern in any plant. You want to avoid overpressure, over-temperature readings and overflow. These occur when design limitations of tanks or piping are exceeded, and you can run into ruptures, fires and explosions. Instrumentation — pressure, temp, flow, level, vibration — provides real-time data of your process variables. It lets you know if you're approaching a danger limit so you can trigger an alarm to stop the process. Safety instrumentation systems, or SIS, combine instruments, transmitters and PLCs to monitor the situation and keep operations safe. Leaks are another major concern, not just for product loss but environmental impact, especially with toxic or hazardous liquids or gases. Using integrated designs — like a DP flow compact meter that eliminates impulse lines, which are a main area for leakage — and utilizing diagnostics can help detect plug lines before they become larger problems. Look at the strengths and weaknesses of each instrumentation type and make sure it fits your process.
Traci: How can a site measure difficult points like stacks?
David: Stacks are notoriously hard to measure. We're talking about a very large range of flows and nasty waste gases that can plug lines, cover instrumentation and are very tough on common metals like carbon steel or 316. Older technologies have varying levels of reliability and accuracy due to harsh conditions. We offer an averaging pitot tube that addresses these issues. It takes the average of the DP pressures on either side of the tube and is available in a wide range of materials. It also has built-in purging ports for maintenance and a really wide turndown that allows sites to maintain high reliability over the larger and varied flow rates they see through stacks.
Traci: What can technologies do today, and how can these technologies help achieve leaner and more efficient processes?
David: All flow technologies bring their own strengths for a given application. DP flow is the oldest flow technology — it's simple. You create a restriction in the pipe and measure the change in pressure. But there are other technologies like Coriolis for mass flow with no moving parts, or ultrasonic mag meters with no pressure drop. With DP flow specifically, we have a four-hole conditioning plate that significantly reduces the straight run you need and takes up a very small profile on the line. This reduces piping costs and saves space. Enhanced diagnostics on transmitters support proactive maintenance by detecting process aberrations or entrained water in electronics or impulse tubes. And our upcoming 4051S transmitter offers a 28-to-1 flow turndown. Typically, sites stock multiple transmitters in the warehouse for turnarounds or shutdowns, but with higher flow turndown, you can eliminate stockouts by standardizing on one.
Traci: Are there key considerations for maintenance and calibration with any of these types of technologies?
David: Most sites have standardized routine inspections. Make sure you have proper enclosures and the correct wetting material to combat corrosion or erosion long-term. Following the manuals and quick-start guides we ship is key to preventing common issues. Installation issues were one of the most common things I heard in technical support. Our manuals offer detailed guidance on where installations should occur to minimize safety concerns. I'd highly recommend using our technical support team — they have decades of experience across all technologies. On our website, we also have customer-facing documentation and AI-supported technical support chat. For calibration, it shouldn't be arbitrary — it needs to be based on your specific process. Harsh environments cause more drift, so calibration may be required more often than in cleaner processes. Critical applications like custody transfer or compliance systems may need more frequent calibration. And traceability matters — Emerson has NIST traceable calibrations on all our flow devices done at our calibration stand. We can do additional calibrations if required.
Traci: What are some other things that Emerson has that set its technology and meters apart? What makes them special?
David: It's the quality of the builds and the minds behind them. We're industry leaders in several areas — our pressure transmitters are industry-leading, and we invented Coriolis technology. Our DP flow offering combines industry-leading pressure transmitters with specialized builds of our primary elements. Emerson has a strong history of specialized instruments through engineered solutions. Particularly difficult applications that don't fit standard products are areas where we excel — we work directly with customers to find customized solutions when other flow companies might pass. Given our wide range of instrumentation, there are many spots in a chemical plant where they can be used. We offer a large range of approvals, certificates and additional testing for major projects like greenfield and brownfield expansions. Within the next year or two, we have a large slate of upcoming products, including the new 4051S transmitter with Bluetooth connectivity, enhanced diagnostics, relay switches and a universal pressure range that eliminates the need to stock multiple transmitters.
For more information, visit: Emerson.com/DPFlow