Water hammer accident

A five-person crew was valving in a second stage reheater at an electric power generation station. They were slowly opening two valves to bring the reheater online. Two of the employees were stationed at one valve, and the other three were at the second valve. Two other employees were working in the immediate area, observing the reheater's drain tank levels after having adjusted an automatic valve about 30 minutes before. The drain line for the reheater ruptured downstream of the valves, releasing steam and hot water into the area. The rupture was caused by excessive pressure in the line as a result of a water hammer. The water hammer was caused by the presence of lower pressure on the downstream side of the valves than on the upstream side. This produced a back flow in the line. The operating procedure for the valves in the line during start up operations had been changed earlier in the year to eliminate water hammer that had occurred previously. However, the new changes were not incorporated into the written operating procedures being used at the time of the accident. Seven employees (all five members of the work crew plus the two other employees working in the area) received second-degree burns to multiple parts of their bodies. They were hospitalized for their injuries.

Steam flushing incident

At approximately 9:30 a.m. on January 19, 2005, Employee #1 and Employee #2, were isolating and cleaning a series of three pumps at a refinery in California, while Employee #3 observed the cleaning operation from a distance. The three workers were starting up the refinery's crude unit. They were experiencing screen plugging from crude unit particles inside the crude unit's prefractionator reboiler pump (pump). The screens commonly become plugged during start-up operations. After the charge pump is isolated, workers clean the pump body by injecting pressurized steam into it. Normally the mix of residual crude oil and pressurized steam is removed through a small outlet in the valve body. Employee #1 connected a 40 psi steam line to the top of the pump body. The flexible removable steam line connects to a Chicago fitting on the top of the pump. Just before the explosion, Employee #1 had cracked open the steam line, letting steam into the pump. An uncontrolled pressure event immediately ensued. The overpressurization of the pump body assembly caused the pump suction flange, strainer outlet flange, and flex connector to blow out violently. The spraying hot oil and the fire started by the explosion caused burns to Employees #1, #2, and #3. Employee #1 sustained third and second degree burns over 50 percent of his body and later died. Employee #2 suffered first and second degree burns over his back. Employee #3 suffered first degree burns on his face. Employees #1 and #2 were treated at the Hospital. Employee #3 was treated locally.
Source: OSHA.gov

OSHA's Top 10 Most Frequently Cited Standards FY 2018

OSHA's Top 10 Most Frequently Cited Standards 

(Source: https://www.osha.gov/Top_Ten_Standards.html
for Fiscal Year 2018 (Oct. 1, 2017, to Sept. 30, 2018).

The following is a list of the top 10 most frequently cited standards following inspections of worksites by federal OSHA. OSHA publishes this list to alert employers about these commonly cited standards so they can take steps to find and fix recognized hazards addressed in these and other standards before OSHA shows up. Far too many preventable injuries and illnesses occur in the workplace.

1. Fall protection, construction (29 CFR 1926.501) [related OSHA Safety and Health Topics page]
2. Hazard communication standard, general industry (29 CFR 1910.1200) [related OSHA Safety and Health Topics page]
3. Scaffolding, general requirements, construction (29 CFR 1926.451) [related OSHA Safety and Health Topics page]
4. Respiratory protection, general industry (29 CFR 1910.134) [related OSHA Safety and Health Topics page]
5. Control of hazardous energy (lockout/tagout), general industry (29 CFR 1910.147) [related OSHA Safety and Health Topics page]
6. Ladders, construction (29 CFR 1926.1053) [related OSHA Safety and Health Topics page]
7. Powered industrial trucks, general industry (29 CFR 1910.178) [related OSHA Safety and Health Topics page]
8. Fall Protection–Training Requirements (29 CFR 1926.503) [related OSHA Safety and Health Topics page]
9. Machinery and Machine Guarding, general requirements (29 CFR 1910.212) [related OSHA Safety and Health Topics page]
10. Eye and Face Protection (29 CFR 1926.102) [related OSHA Safety and Health Topics page]

 

An Explosion Protection Strategy | Engineer Live

An Explosion Protection Strategy | Engineer Live

Explosion due to suspended graphite cloud and static electricity

 On September 3 2018, a blast destroyed one of 400 buildings at the RDM plant in South Afirca, which manufactures artillery ammunition.Eight workers were killed.
 As per a report published Herald Live, "Based on extensive testing, assessments and elimination of other initially suspected causes, the most likely cause of the explosion was a build-up of electrostatic electricity in a suspended graphite cloud due to the triboelectric effect, and a subsequent discharge which ignited airborne propellant in the blending drum.”
Read the article in this link

Control of Hazardous Energy by Lock-out and Tag-out

Control of Hazardous Energy by Lock-out and Tag-out: Why Lock-Out and Tag-Out?Lock-out and tag-out (LOTO) is a critical part of a strong all-around safety program. In LOTO, maintenance employees work with production employees to positively prevent all forms of hazardous energy from causing harm. Hazardous e

Hazardous Energy Control Programs : OSH Answers

Hazardous Energy Control Programs : OSH Answers

Loss of containment incident

On September 21, 2003, Employee #1 and several coworkers were working at a chemical plant that deals with nitric oxide. On the day of the accident, a major leak occurred in a stainless steel distillation column. The nitric oxide leaked into the facilities surrounding vacuum jacket and into the atmosphere through a pump, which controls a high quality vacuum inside the jacket to minimize transmission of heat toward the cryogenic distillation columns. A brown cloud quickly formed and the temperature and the pressure inside the distillation column and its surrounding vacuum jacket began to rise. The leak was detected and the vacuum pump was turned off to halt the leakage of nitric oxide into the atmosphere, allowing the pressure inside the column and vacuum jacket to stabilize around 130 psi. Although stabilized, the pressure was far above the normal pressure of less than or equal to atmospheric pressure (14.7 psi). Approximately 3 hours later, an explosion occurred. The operation and process were destroyed, and debris flew through the plant. Employee #1 suffered lacerations due to flying glass and was treated at a local hospital, where he received stitches and then released. A detailed investigation determined that the cause of the explosion was most likely due to something inside the vacuum jacket initiated the dissociation of nitric oxide, a reaction that is very rapid, exothermic, and self-propagating once started.
Source Osha.gov