PT Notes

Field Tour for PHA

In conducting a PHA for an existing process, it is good practice for the PHA team to conduct a field tour of the process being reviewed. However, the PHA team leader may encounter resistance from team members, especially for a PHA being conducted for an older process for which previous PHAs have been conducted. Team leaders need to be prepared to deal with such resistance and be able to provide guidance to the team on what to look for during a field tour.

The team leader should emphasize to the team that it is important to have an open and inquisitive mind and that they should be ready to question everything. Team members should be encouraged to look at the process as though they had never seen it before. The team leader can focus the attention of team members by having them question and address issues such as:

• What is taking place in the process area? Why are actions being taken in a particular way?
• Are vessels, piping, valves, and other equipment installed in a way that permits ease of operation and maintenance?
• What seems unusual or out of place in the area? For instance, why are there blind flanges lying around on the ground? They should be installed on unused vent / drain lines per the P&IDs.
• Why is a process area still cluttered after a shutdown? Why are nuts and bolts, flanges, tools, scaffolding, ladders, etc. still lying around? (Poor housekeeping can be an indicator that personnel workloads may be too high due to lack of resources).
• Is the routing of relief valve discharge lines appropriate? Could the discharge from a relief valve impact personnel in the area?” (On one site, a flammable vapor relief valve discharge line from the second floor discharged directly over a ground floor walkway that was regularly used by personnel).
• Are pump and equipment bases and foundations free from corrosion / erosion and/or other degradation? Teams should especially check on piping and equipment supports that can expand and contract as their operating temperatures change over time (such as steam and cryogenic piping).
• Are the grounding wire jumpers that are required for electrical continuity for piping flanges and field instrumentation and their wire supply conduit still in place? (On one site, the PHA team found six instruments whose grounding connection wires were broken or corroded so badly that the wire was in two pieces. Only two of the broken grounding wires were marked for replacement and the repair tags were at least two weeks old.)

Everything about the status quo of the process should be questioned and the team should look for what is out of the ordinary or unusual, or incorrectly designed or maintained.

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