Fluke aficionados have long had to work around the lack of a fully functional control valve testing tool. “I’ve wanted to put valve test capability in one of our tools for 10-15 years, for example, in a documenting calibrator,” says Jim Shields, product marketing manager, Fluke Corp. “But, our documenting calibrators don’t yet have the needed functionality.”
Valve testing relies on the ability to source 4-20 mA and communicate HART simultaneously. Fluke’s new 710 mA Loop Valve Tester is its first tool to combine those capabilities.
The company’s 709H calibrator looks similar, “but it doesn’t have the needed smarts, 4-20 mA sourcing and HART Comms,” Shields says. “The 710 can measure and power a transmitter, and communicate HART. But, its mission is testing valve calibration and performing valve diagnostics.”
In use, the 710 can read the digital HART on the 4-20 mA signal, command the valve to go to a position, read the pressure applied to the actuator, and read the exact valve position. “When I command 50%, does it go to 50%?” Shields asks. “Then, the pressure should change smoothly, with some non-linearity near fully open and fully closed. From 5% to 95%, pressure and valve position should change smoothly. Spikes in pressure mean stickiness.”
With built-in test procedures and an intuitive interface, the Fluke 710 allows technicians to quickly and easily perform valve tests, while the valve test quick-check results provide at-a-glance diagnostics to make faster maintenance decisions. It features preconfigured valve tests for reliable and repeatable testing. The built-in routines include:
- Manually changing the mA signal and viewing the HART position and pressure variable information.
- Full-range ramping of the mA signal from 4 to 20 to 4 mA while recording the 0-100-0 percent position, or the pressures applied that move the valve from 0-100-0 percent.
- Stepping the mA signal on the input to the valve in steps and evaluating the valve response to the mA input changes.
- Speed tests to determine how fast the valve can open or close.
- Bump and partial-stroke tests that measure valves over a portion of their range so they can be tested in a live process.
In a full-range test, the 710 ramps in adjustable-mA increments, logs position and pressure, and generates a test record. “Users can key in a test tolerance from 1-20%, and it gives a result of test tolerance vs actual—a test record. If it’s within tolerance it’s “good,” at tolerance “marginal,” and if it exceeds tolerance it notifies the user “Bad,” Shields says.
Test results are stored in the memory of the 710, where they can be uploaded to the included ValveTrack analysis software. ValveTrack allows users to upload and plot logged valve tests taken in the field, compare previous uploaded tests to recent tests, view valve test history by HART Tag ID, and export valve test data to CSV for additional analysis in Microsoft Excel.
“Other companies’ tools are available for $20,000-60,000 that measure everything, but they require experienced users and the valve may have to be removed and put on the tester. Doing that, a two-person team can test six to eight valves a day,” Shields says. For about $2,500, “In a five-minute test, the 710 can give you the confidence the valve is moving and performing as expected in between more comprehensive maintenance.
“People have used our calibrators to test valves for many years, using a procedure. The 710 simplifies and streamlines that, and obtains a true valve signature that can be uploaded to document its performance and diagnose any issues.”
For more information, visit www.fluke.com/valvetester.
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