Electricity + Control July 2019

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CONTROL VALVES + ACTUATORS

Quick and reliable mA loop valve testing

- Compare previous uploaded tests to recent tests - View valve test history by HARTTag ID - Export valve test data to CSV for additional analysis in Microsoft Excel. Enquiries: Comtest. Tel +27 (0)10 595 1821, or email: sales@comtest.co.za

(which moves the valve) can be seen with the HART communication protocol. The 710 features pre-configured 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 and evaluating the valve’s response to the mA input changes - Speed tests to determine how fast the valve can open or close - Bump and partial stroke tests that help test valves over a portion of their range so they can be tested in a live process. 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

Control valve testing has generally involved the use of complicated testers that require extensive training, the removal of the valve, and often one to two hours of test time on the bench. An alternative now available from Comtest is the new Fluke 710 mA Loop Valve Tester. The device allows technicians to source the 4-20 mA signal while it interrogates HART data to collect critical information about a valve’s position and status, providing a quick check while the valve is in place. With built-in test procedures and an intuitive interface, the Fluke 710 allows technicians to perform valve tests quickly and easily. The quick-check valve test results provide at-a-glance diagnostics to enable faster maintenance decisions. With the tester’s built-in HART communication function, technicians can source a 4-20 mA signal to cause the smart control valve to move, while simultaneously interpreting the valve’s HART feedback signal to determine whether the valve is moving to the expected position. In addition to positional information, the measured pressure delivered from the valve’s internal I/P The Ingelfingen-based valve specialist GEMÜ has launched electrical position indicators for manually and pneumatically operated quarter- turn valves. For automated process plants, the GEMÜ LSC limit switch box detects the valve position. This is signalled by an optical indication and transmitted to the plant control system. Up to four position feedback messages can be sent. The GEMÜ LSC position indicator can be fitted to all quarter-turn valves, such as butterfly or ball valves, with a VDI/VDE 3845 standard interface. GEMÜ offers solutions pre-installed on GEMÜ butterfly valves or ball valves, but retrofitting is also possible. In addition to simple micro-switches, the GEMÜ LSC limit switch is available with 2-wire or 3-wire proximity switches. It has a protection rating of IP67 and is suitable for explosion-proof areas according to ATEX and IECEx. The GEMÜ LSC limit switch box has been checked to ensure the reliability of safety functions and has SIL approval.

The Fluke 710 mA Loop Valve Tester enables quick and easy testing of valves while they are in place.

Limit switch box for quarter-turn valves

A 3D optical position indicator or open/ closed LED display is optionally available. A variety of electrical connections are also available, such as an M20 cable gland, an M12 plug or an NPT threaded connection. Besides the existing GEMÜ LSF inductive dual sensor, the company is expanding its range of electrical position indicators for quarter-turn valves with the addition of the GEMÜ LSC limit switch box, enabling quarter- turn valves to be integrated and controlled in automated plants. The GEMÜ Group develops and manufactures valves and measurement and control systems for liquids, vapours and gases, with particular expertise in solutions for sterile applications. Enquiries: GEMÜ, visit www.gemu-group.com

GEMÜ 481 Victoria butterfly valve with GEMÜ LSC electrical position indicator fitted.

28 Electricity + Control

JULY 2019