Introduction: A contractor suffered thermal burns while hydroblasting near an open and assumed-isolated vessel in a petrochemical facility. To determine the cause of the incident, consequences, and the responsibilities of the involved parties, Baker & O’Brien visited the site, reviewed the equipment diagrams, procedures, permits, and isolation plans. We issued an expert report that the parties used to negotiate a settlement.

Hydroblasting is the term for high-pressure water washing, an industrial maintenance cleaning technique used to remove unwanted materials from plant equipment. Since hydroblasting is performed on the inside of plant process equipment, the facility is typically shut down, equipment deenergized, and opened up to perform the maintenance activity. Companies hire specialty contractors to perform these services.

Preparing complex equipment for maintenance is a common yet complicated task for plant operators. Maintenance worker safety depends on the operator properly identifying and isolating energy sources and the worker verifying that energy isolation and other hazards are addressed before starting work. However, plant equipment may have many energy inputs, including electricity, steam, water, chemicals, and gases. These energy inputs often arrive at the equipment in a tangled web of piping and conduit that can be difficult to discern.

A contractor was hydroblasting a pipe immediately adjacent to an open nozzle at the top of a vessel. This open hole, created by removing a piping spool to provide access for hydroblasting, collected the water effluent from the hydroblasting. Several hours into the work, steam and hot polymer from the vessel erupted from the nozzle and contacted the contractor, resulting in burns.

Baker & O’Brien was asked to determine the cause of the incident and its responsibilities. We analyzed the vessel isolation plan, piping and instrument diagrams (P&IDs), procedures, and work permits involved with the incident. We also compared the work practices to industry and OSHA standards. We determined the cause of the “eruption” and provided expert opinions on contributing factors to the injury, as well as the responsibilities of the involved parties. Baker & O’Brien prepared a technical expert report and were prepared to testify at trial when the matter settled.