Pipefitt er Struck by Pressurized Pipe and Killed

 On March 6, 2018, a 49-year-old pipefitter was hit in the chest by a pressurized 12-inch diameter polyvinyl chloride (PVC) pipe during a hydrostatic pressure test of a fire suppression system. The sudden pipe movement was attributed to a pipe joint connection failure in a buried section of the pipeline. The failure was due to torque shear bolts at the joint connection that were not tightened, which was missed during the utility installation process and the work inspection prior to the incident.

Read the incident in this link

Employees Chemically Burned by Leaking Dimethyl Sulfate Pipe (leak caused by thermal expansion of pipeline)

At 11:30 a.m. on June 20, 2007, Employees #1, #2, #3, and #4, who worked for Scaffolding Company, and Employees #5, and #6, who worked for Plant Services Company, and Employees #7 and #8, who worked for a chemical manufacturer, were hospitalized after being exposed to dimethyl sulfate (DMS) in the ethoxylation area where it was used in reactors 4 and 5. Employee #7 was an operator who moved bags containing chemicals into the area in order to add it to reactor 4. Employee #8 was a mechanic that worked unplugging an auger at reactor 4. 

Employees #7 and #8 started working at 7 a.m. at reactor 4. Employees #1, #2, #3, and #4 dismantled a scaffold at a platform at the reactors. Employees #5 and #6 removed and installed new insulation on piping at a platform at the reactors. The host employer did not become aware that employees were exposed to DMS until about 2 p.m., when workers were discovered having chemical burns. Employees worked on a raised platform around the two reactors. In order to enter and leave the area, they walked along a path between two the reactors that was only 30 inches wide, and a pipe that contained DMS which ran overhead between the reactors. The piping system normally operated at 5 psi, but thermal expansion of DMS caused pressures over 300 psi and caused a valve on the overhead pipe to leak this extremely hazardous compound down onto employees that worked beneath the pipe. 

Source:OSHA.gov

FIRE AND EXPLOSION HAZARDS WITH THERMAL FLUID SYSTEMS

"Incidents relating to thermal fluid systems are unfortunately more common than we might realise,
and can be extremely serious. The fire and explosion hazards with thermal fluid systems have been
re-emphasised by recent incidents. These incidents have a direct bearing on the estimated 4,000 UK
companies that operate thermal fluid systems.
Water or steam can be used as heat transfer fluids, but when high temperatures are needed
organic fluids, which are capable of forming explosive atmospheres, are often used. Although
fire and explosion hazards of low flash point flammable liquids are generally recognised, similar
hazards with high flash point materials, such as thermal fluids, are often missed. These heat transfer
fluids are often handled at temperatures above their flash point.
However, many people are unaware that heat transfer fluids based on mineral oils
degrade over time. This degradation can cause the fluid’s flash point to decrease dramatically, so
that thermal fluids which were not flammable at the operating temperature when they were initially
installed may, over time, become flammable at the operating conditions. Also, high flash point
materials (such as thermal fluids), can form explosive mist atmospheres when handled under
pressure, even at temperatures below the flash point".

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EXPANSION BELLOW INCIDENT

"In this study, the explosion failure of a bellows expansion joint made of Type 304 stainless steel (UNS S30400) in a pipeline conducting methane (CH₄) gas at 400 °C is analyzed. Using the simulation mechanical software, the behavior of the pipeline during the working condition was investigated.

Observations of the metallographic sections indicated that corrosion was involved in the cracking of the bellows that led to the explosion. After investigating the fracture surface, it was noted that the cracks occurred at dimples in the bellows. The presence of hydrogen sulfide (H₂S) in the gas stream resulted in stress corrosion cracking". 

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Ammonia can cause fires and explosions

 Employees #1 and #2 were engaged in a turnaround operation at a fertilizer manufacturing plant. They were standing on a work platform at a height of approximately 20 ft, removing an 18 in. diameter manway cover on the east monoethylamine stripper in Ammonia Plant #2. The top manway cover on the east stripper had already been removed and they were using a #5 spline drive, #3913 air-operated impact wrench to open the bottom manway cover. They had removed all but one of the bolts when there was a sudden flash fire and explosion. Employee #1 suffered broken bones and suffered second-degree burns over 60 percent of his body. He was killed. Employee #2 suffered minor burns on his arms and legs. The source of ignition is not known. 

 

Source:osha.gov

COMMON CHEMICALS CAN CAUSE UNCOMMON REACTIONS

An employee was cleaning the floors in a restaurant and mixed together sanitizer and heavy duty floor cleaner. The sanitizer contained chlorine and the floor cleaner contained ammonia which, when combined, creates chlorine gas. The chlorine gas was drawn into the ventilation system and circulated throughout the restaurant. Coworkers were evacuated when the white gas cloud formed, and three employees were taken to the hospital with respiratory problems. 

Source:osha.gov

A change in receiving storage tanks kills one

A road tanker loaded with ammonia hydroxide was being unloaded into a polyethylene storage tank at the site of a chemical distributor.  This change was not taken through a MOC. The unloading was being accomplished by filling the vacant space above the liquid inside the tanker with compressed air, a standard method of unloading such tankers. When the tanker was emptied, the compressed air surged into the polyethylene storage tank, which was not designed to withstand that kind of pressure. The polyethylene tank ruptured, releasing a substantial volume of ammonia into the air. An employee, who was close to the drain valve on the tanker, inhaled a substantial volume of ammonia, He suffered serious chemical burns to his lungs, resulting in his death. 

Source:osha.gov