We routinely discuss the challenges and risks of performing Line/Equipment Opening (LEO) tasks, with one of the top 5 challenges being the “means used to verify” the pipe/equipment is at a Zero-Energy-State (ZES). The factors that occurred in this incident probably happens by the hour in the process industry; it is why we ALWAYS have on a layer of PPE that will protect us when this type of failure occurs.
On June 8, 2020, at 10:00 a.m., Employee #1, 29, was working for a pipe fitting contractor. Employee #1 removed steel bolts from a flange fitting to open the process piping.
The job site was a roofing materials production facility, and the work was adding process piping and equipment to enlarge an existing chemical process.
The scope of this work included tying in new relief valve piping to the existing line process piping. This line piping is NORMALLY empty.
The additive is a corrosive chemical with a pH of 10.8.
When deliveries are made, the piping conveys the additive from the delivery truck to a fixed storage tank located outdoors. Only during deliveries does the line contain the flowing additive. However, approximately 8 gallons of residual liquid remains trapped in a 2-inch vertical pipe riser. This liquid is trapped by a one-way check valve downstream of the riser.
Employee #1 was opening the pipe flange to drain this residual liquid before adding the relief valve. Employee #1 began to open the four-bolt pipe flange between the pipe riser and check valve.
Employee #1 removed the two (2) bottom bolts from the flange to allow the residual additive to drain safely from this line. Employee #1 observed that liquid had stopped flowing from the pipe flange and began to remove one of the two (2) remaining top flange bolts.
Unknown to employee #1, the gasket inside the pipe flange became displaced during drainage. The stoppage was due to the dislodged gasket blocking this flow. It was not possible to detect the displaced gasket by visual means, thus Employee #1 removed the third bolt allowing the residual additive to drain onto Employee #1.
The clothing of Employee #1 became saturated in the torso and waist areas. Employee #1 was hospitalized to treat 2nd-degree chemical burns.
| Violations/Penalties | Serious | Willful | Repeat | Other | Total |
|---|---|---|---|---|---|
| Initial Violations | 1 | 1 | 2 | ||
| Current Violations | 1 | 1 | 2 | ||
| Initial Penalty | $9,639 | $0 | $0 | $0 | $9,639 |
| Current Penalty | $5,783 | $0 | $0 | $0 | $5,783 |