The list of consumer experiences made easier over the last 20 years is stunning. Technology has made the way we used to record a television show, search for a new home, and deposit money into a bank account look like manual labor. There’s nothing wrong with finding a blank tape and taking one’s chances with the VCR, spending an afternoon driving around on a quest to find a ‘For Sale’ sign in a nice neighborhood, or rushing to the bank to deposit a check on payday. These methods will still get the job done, but with greater difficulty than necessary. Technology has given us ways to accomplish the same goals in less time and with less trouble.
The Internet has brought similar convenience to the world of process instrumentation. Operators can find unit specs and configure orders online to procure a level product in a fraction of the time it used to take. But convenience-creation doesn’t end when one walks on the plant floor. The advent of ultra-focused radar sensors with 80 GHz transmission frequency is making it easier than ever to use a radar sensor for accurate level measurement through a ball valve. This advancement relieves an old headache shared by operators in multiple industries.
26 GHz radar sensors and ball valves: A difficult combination to manage
Although ball valves are small, they play a big role in applications with harsh liquids. Using a ball valve to separate a process instrument from a mounting nozzle allows operators and technicians the freedom to make instrument repairs on the fly without interrupting the process. Plants can ill afford to run at reduced capacity simply because a measurement device needs cleaning, so they install ball valves to keep product moving at all times. Attaching a 26 GHz radar sensor to a ball valve and using the sensor to measure level has historically been challenging, like house-hunting without a preliminary Google search: Doable, but difficult.
Ball valves contain many interior surfaces that reflect radar signals, and given that these valves are often used in combination with a bleed ring to trap any gas leftover after the valve is closed, signal noise is often amplified. All of these reflections make it difficult for operators to discern which signals are from the valve and which are from the media. Operators then turn to instrumentation manufacturers for help, and service technicians do what they can to make it work, but the best solutions are often a Band-Aid. Before long, the manufacturer’s tech is back on site, servicing the 26 GHz radar again.
Another option operators have for making the most of a 26 GHz sensor on a ball valve is involving the instrument manufacturer in valve selection. VEGA Americas finds that even when it is allowed to choose the ball valve, the fit has to be perfect: metal-seated with a consistent diameter all the way through and a continuous path for the radar. Such a valve has to be special ordered at great expense to the operator. Even then, results are not guaranteed. Again: doable, but difficult.
80 GHz radar technology presents users with a new option for liquid level measurement, even when mounted on a ball valve. Higher-frequency sensors emit a narrower radar beam, so fewer signals are created by the valve’s interior. This minimized noise creates an easier experience for users who now have a clear picture of the level inside a tank without installing a costly, special-ordered valve. 80 GHz radar sensors work wonderfully with any -off-the shelf 3-in. or 4-in. ball valve. The bigger the valve, the clearer the signal, but 80 GHz sensors are also performing well on 2-in. ball valves. A Canadian refinery recently discovered this firsthand.
The power of focus: A brief case study
A major refinery in southern Ontario stores butane in enormous spheres, approximately 55-feet in diameter. Producing around 75,000 barrels/day, the refinery does not have the luxury of shutting down the sphere to maintain a process instrument. Perhaps that’s why it settled for intermittent level measurement for seven years. The refinery wasn’t in any danger—it has a backup system in place—but the guided wave radar and float it was using caused constant frustration. Operators used a period of routine maintenance to find a more reliable level measurement solution.
In addition to its immense size, the sphere also features a 2-in. ball valve atop a mounting nozzle. A valve that small may provide a challenge for a radar sensor, even one with hyper-focused 80 GHz transmission frequency. Not so in the giant butane sphere. A VEGAPULS 64 was installed on the valve, and it’s working better than any process instrument previously installed in the application. The photo below comes from the sensor’s adjustment software. The green spike on the graph is the clear signal reflected from the butane back to the VEGAPULS 64. Doable, not difficult.
80 GHz technology is the process industry’s answer to the DVR or the mobile banking app: It makes a difficult task easy. Before the VEGAPULS 64 hit the process control market, ball valves presented a major challenge to using radar sensors to measure liquid level. There are too many reflective surfaces and space is too tight for 26 GHz sensors to work reliably without frequent upkeep. 80 GHz sensors change all the landscape because of their improved focus. Operators can now pair practically any 3-in. or 4-in. ball valve (and most 2-in. ball valves) with a non-contact radar instrument that gives accurate readings of low-DK products in difficult environments. Expect 80 GHz sensors to become ubiquitous in industries where radar devices used to be off limits, and for operators to enjoy easier, less-intensive liquid level measurement.