High Pressure/Temperature Steam Release During Engine Room Repair
A shipyard worker was preparing to replace a high-pressure steam valve that was faulty and leaking
in an engine room. The valve was part of a 600 psi steam system on a vessel. Other shipyard
personnel had previously located all the valves and drains and isolated the steam system according
to the ship’s as-built drawings. All the drains indicated on the as-built drawings of the ship were
open and depressurized. The drains were then marked with tags.
As one of the workers loosened the bolts around the faulty valve a tremendous burst of steam was
suddenly released. The steam—under high pressure, at 385 degrees Fahrenheit—knocked the worker to
the ground and produced third-degree burns on more than 60 percent of his body. The worker died two
days later in the hospital. Errors and omissions on the ship’s as-built drawings had prevented
shipyard personnel from completely isolating and draining the steam system.
What went wrong?
Accurate drawings—free from discrepancies— are essential for effective energy isolation. Shipyard
personnel were not properly trained to conduct a visual check of all drains and valves in a steam
system that is to be drained and depressurized. Drain connections on all dead interconnecting
systems were not opened and observed to ensure effective isolation. Employees authorized to perform
steam system repairs should be directly involved in the isolation and lock out tag out of the
system. Direct involvement by workers in the lock out, tag out process ensures their understanding
of the operation or process hazards that the lock out, tag out is designed to control and how to
avoid or control these hazards. It is essential for ship’s personnel and repair contractors to
communicate and coordinate about the isolation and lock out tag out of the ship’s systems.
Be careful not to touch the pipes or valve too quickly. Approach them slowly to feel if heat is
radiating from them first. A thermal gun could have been used to check the temperature around the
valve. Verify that the steam system is drained and the drain valve is open. If the pipe and
valve are very hot, they may still contain steam under pressure.
