So You Think Your Flow Meters are Correct? - Part 3

In Parts 1 and 2, I wrote about some of the things that I found after doing a verification of the flow meter calculations and transmitter configurations in our diesel hydrotreater unit.  I discussed how mistakes during engineering, procurement, startup and ongoing maintenance can lead to flow meter errors.  In this post, I will describe some of the things that we have done to prevent these errors from causing problems in the future.

Double Check Flow Calculations

When you receive flow meter calculations done by others, take the time to double check the results.  We have decided to standardize on the Instrument Toolkit Software (Rosemount Instrument Toolkit) by Rosemount to do our internal flow meter calculations.  When we receive calculations from others, we reproduce the calculations in the Instrument Toolkit.  This not only verifies the results but allows us to have a method to revise the calculations if process conditions change.

Consolidate Your Documentation

I hate to admit it, but we had flow meter documentation stored in a variety of places.  For many years, we tried to keep paper datasheets done before the digital age in a master “Orifice Book”.  I later years, this was moved to an electronic spreadsheet that frequently did not contain all of the data required to reproduce the calculations.  We also had datasheets stored in the project manuals that get distributed at the end of a major project and in electronic project files that we archive after a project is complete.

We are now in the process of locating as much of this documentation as we can and storing it in digital format in a common location.  Having a single location for all of this documentation has proved extremely valuable.

Audit Your Field Devices

We have the AMS Intelligent Device Manager (AMS Device Manager) integrated into our DeltaV System.  We have DeltaV Maintenance Workstations that are also AMS Clients distributed throughout the refinery.  Engineers and Instrument Technicians use these workstations to communicate to our HART and Fieldbus devices.  We also use the QuickCheck Snap-On (QuickCheck Snap-On) to pull data from multiple HART and Fieldbus devices.  QuickCheck has proven invaluable for auditing field devices to insure that they are properly configured.

Review Your Maintenance Work Practices

Take a look at your work practices and procedures to insure that when transmitters are modified or changed that everything gets done correctly.  This includes the DCS side of things because DCS changes frequently have to be made at the same time that devices changes are made.

I would be interested in feedback from other users that have struggled with similar flow meter issues.