Project Synopsis

Determine refinery maximum intended hazardous liquid inventories to help client comply with PSM regulations.

Project Summary

MAXIMUM INTENDED INVENTORY (MII) SUMMARY

The client owns and operates a petroleum refinery in the United States.  Process Engineering Associates, LLC (PROCESS) was contracted to determine the maximum intended hazardous liquid inventories for the facility processing units of the refinery to help the client fulfill its obligations specified in the Occupational Safety and Health Administration (OSHA) Process Safety Management of Highly Hazardous Chemicals Regulation, 29 CFR 1910.119.


PROCESS used dimensional data shown in the equipment data blocks of the piping and instrumentation diagrams (P&IDs) provided by the client to determine equipment volumes.  PROCESS used equipment volume spreadsheets provided by the client and the equipment files to supplement missing information from the equipment data blocks as required.

When possible, PROCESS also used the detailed process data provided by the client (e.g., storage tank inventory lists and high liquid levels shown on the P&IDs) to help determine equipment volumes.  However, when detailed process data was not readily available, PROCESS used conservative assumptions based on its knowledge of, and experience with refinery operations to estimate the inventory of those pieces of equipment.


Due to the large number of processing units involved in the study, PROCESS created a volume function in Visual Basic that collected the equipment and process data, entered in the MII tables, and calculated the equipment volume based on the equipment type selected by the user.  This allowed PROCESS to populate the MII tables more efficiently, which translated to a cost savings for the client.  In addition, a mass inventory was calculated using the calculated volume and the corresponding density of the fluid in the unit.

Industry Type

  • Petroleum Refining

Utilized Skills

  • PSM compliance support
  • Visual Basic programming

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