Common issues in debugging the DVC6200 locator

I have dealt with two cases related to the 6200 positioners; in both cases, it was not a fault with the positioners themselves but rather an issue with their installation and calibration. Our boiler temperature and pressure reduction station is located in a enclosed space on Platform 8M of the facility, where the ambient temperature can reach up to 50 degrees Celsius. The original Leslie temperature and pressure reduction valves were equipped with ABB valve positioners. During this major renovation, actuators from WuZhong Instruments were used. Due to the high ambient temperature, a separate Fisher 6200 valve positioner was chosen and installed away from the valve itself. The image showing the modified setup looks like this: This is a medium-pressure reduction valve that reduces the pressure from 3.9 MPa to 0.5 MPa. After the system started operating, the pipes expanded due to heat, causing the relative position between the 6215 (individual valve position sensor) and the magnetic strip to change by about 10 cm. After adjusting the installation position, the 6215 was fixed to the support column of the actuator using a transmitter mounting bracket, so that the magnetic strip would not shift relative to the 6215 due to pipe deformation. Here is the diagram of the modified installation. Before initializing (self-calibrating) the positioner, it is necessary to check whether the feedback magnetic strip is positioned in the middle of the 6215’s groove. It is best for the center of the feedback magnetic strip to align with the center of the valve position sensor when the valve is at 50% position. The magnetic strip must not rub against the groove of the 6215, otherwise calibration will not be successful. In another case, a colleague tried to reinstall a rotary 6200 positioner after removing it, but was unable to complete the self-calibration. Upon inspection, it turned out that the feedback magnetic strip had not been installed in the feedback groove of the positioner

The most common fault is a blocked or damaged IP, that is, the locator does not output.

The problem is how to assemble it, because the locator requires a bracket to work with the valve. So without a suitable bracket, it cannot be used effectively.