An explosion occurred at a chemical plant in an analysis room containing various analyzer instruments, including a gas chromatograph supplied with hydrogen. A contract operator was performing work to install a new vent line to a benzene analyzer that was part of a group of CO2 analyzers, but separate and unrelated to the gas chromatograph. During the process of this work, a plant supervisor accompanying the contract operator doing the work had an indication of flammable gas present on a portable detector. This was in conflict with the fixed gas detector in the analysis room that was indicating that no flammable gas was present. As a precaution, the plant supervisor immediately cut off the hydrogen supply and, along with the contract operator, began the normal task of determining if view more

A refinery hydrocracker effluent pipe section ruptured and released a mixture of gases, including hydrogen, which instantly ignited on contact with the air, causing an explosion and a fire. Excessive high temperature, likely in excess of 1400°F (760°C), initiated in one of the reactor beds spread to adjacent beds and raised the temperature and pressure of the effluent piping to the point where it failed. An operator who was checking a field temperature panel at the base of the reactor and trying to diagnose the high-temperature problem was killed. A total of 46 other plant personnel were injured and 13 of these were taken to local hospitals, treated, and released. There were no reported injuries to the public.

Property damage included an 18-inch (46-centimeter) long tear in the view more

A hydrogen reformer furnace at a refinery was shutdown for maintenance to remove and cap the inlet and outlet headers of some radiant tubes that had previously developed hot spots and been isolated by externally pinching them off at the inlet. A decision was made to leave steam in the steam-generating circuit during this maintenance operation to prevent freezing. After maintenance was complete, the startup procedure required the furnace to be first heated up to 350°C (662°F) prior to introducing 4136 kPa (600 psig) steam into the radiant tubes. Just after the 4136 kPa (600 psig) startup steam was introduced into the reformer furnace inlet, the control room alarm journal reported an extreme positive pressure spike at the same time a single loud bang was reported by the operations view more

A hydrogen leak occurred at a plant's hydrogen fill station when a vendor's hydrogen fill truck trailer pulled away after filling and caught an improperly stored hydrogen fill line. The driver of the hydrogen truck trailer did not properly stow the hydrogen fill line after filling and failed to verify that the hydrogen fill line was clear of the trailer prior to departure. As the driver pulled away from the fill station, the hydrogen fill line caught on the trailer and subsequently pulled on the hydrogen fill station's ground storage tubes distribution manifold. The force of this pull bent the plant's hydrogen distribution manifold and hydrogen began leaking from a threaded connection and from the hydrogen fill line. The truck trailer driver reported hearing a view more

An explosion occurred within the hydrogen processing system of a chemical plant that produces sodium chlorate for bleaching pulp and paper. The chemical process utilizes electrolytic cells and is pH-dependent. Hydrogen is produced as a byproduct and is utilized as a fuel.

At the time of the incident, the plant was at an abnormal operating level of 25% capacity. A non-routine maintenance operation to repair high-pH liquid piping was in progress. To assist, operations personnel rerouted the high-pH liquid stream to the plant sump. However, in doing this, the liquid eventually made its way back into the electrolytic process by design. Ultimately this created the root cause of the explosive condition in that the pH of the electrolytic process increased faster than the computer- view more

Incident Synopsis
During development tests, a gaseous H2 test tank was over pressurized and ruptured. The tank dome was destroyed.

Cause
The pressure relief valves were set too high. In addition, the tank was not depressurized while being worked on. Safe distances, as required by the procedures for personnel safety, were not followed.

Incident Synopsis
While transferring liquid H2 from a tanker, the burst disk ruptured at 50 psi. The pressure limit for the operation was 30 psi.

Cause
The operator turned on the pressure valve and left it unattended, permitting pressure buildup past the allowed 30 psi.

Incident Synopsis
A technician was welding a cable suspended over a stainless steel H2 instrument line. During the welding process, two holes were accidentally burned through the hydrogen tubing. The operator heard a hissing sound and closed the valve, but the hydrogen had already ignited and it burned his hand while he was feeling for a leak.

Cause
A short during welding caused the pinholes in the tubing containing the gaseous H2.

Summary
A faulty modification to a multiple-gas piping manifold allowed mixing of hydrogen and oxygen that resulted in a storage tube explosion. Several employees suffered severe burn injuries from the incident.

Incident Synopsis
An employee, without authorization, fabricated and installed an adapter to connect a hydrogen tube trailer manifold to an oxygen tube trailer manifold at a facility for filling compressed-gas cylinders for a variety of gases, including hydrogen, oxygen, nitrogen, and helium. A subsequent improper purging procedure allowed oxygen gas to flow into a partially filled hydrogen tube on a hydrogen tube trailer. An ignition occurred in the manifold piping system and a combustion front traveled into the hydrogen tube where, after traveling about a view more

Incident Synopsis
One man was killed and another severely injured while working with a portable battery power supply.

At a test facility, a water-submersible portable battery power supply was used to power lighting. The battery power supply contained two 12-volt lead-acid automotive batteries, a wiring harness, and switching relays mounted in an air-tight case suitable for submersion in water. The case possessed ½-inch aluminum walls and a 13.8-pound lid. The box had been used periodically over two years.

After charging all night, the battery power supply was moved into place and connected to the lighting. Two technicians started to test the unit. One technician rested his hand on the case lid while the second leaned over the lid and threw the switch to activate view more