Many workplaces contain spaces that are considered "confined" because their configurations hinder the activities of employees who must enter, work in, and exit them.
A confined space means a space that:
Confined spaces include, but are not limited to underground vaults, tanks, storage bins, manholes, pits, silos, process vessels, and pipelines.
OSHA uses the term "permit-required confined space" (permit space) to describe a confined space that has one or more of the following characteristics:
Confined space hazards are addressed in specific standards for the general industry and shipyard employment. Also, see OSHAcademy Course 713 for more information.
Confined Space Rescue and Recovery: Oil Field Worker Dies on the Job in California
According to KBAK-KBFX TV station in Bakersfield, California, a supervisor and a welder were in a 15-foot tall tank. They apparently were testing for leaks by adding air pressure inside the tank. This process required having a “false bottom” in the tank. It wasn’t clear if the air pressure had built up under the false bottom. Investigators at the scene said there weren’t any harmful fumes inside the tank at the time of the accident. Eyewitnesses told reporters they heard a “loud sound, like an explosion.”
Crews at the scene used a tripod with a rope, and sent a firefighter into the tank. However, the rescue team found the deceased worker inside the tank. He died from a severe head injury. The other worker at the site suffered a broken ankle.
Source: KBAK-KBFX TV-Eyewitness News- October 3, 2012
Generally, a pressure vessel is a storage tank or vessel that has been designed to operate at pressures above 15 p.s.i.g. Recent inspections of pressure vessels have shown that there are a considerable number of cracked and damaged vessels in workplaces. Cracked and damaged vessels can result in leakage or rupture failures.
Potential health and safety hazards of leaking vessels include poisonings,suffocations, fires, and explosion hazards. Rupture failures can be much more catastrophic and can cause considerable damage to life and property. The safe design, installation, operation, and maintenance of pressure vessels in accordance with the appropriate codes and standards are essential to worker safety and health.
Pressure vessel hazards are addressed in specific standards for the general industry, shipyard employment, and the construction industry.
Hazards associated with compressed gases include oxygen displacement, fires, explosions, and toxic gas exposures, as well as the physical hazards associated with high pressure systems.
Special storage, use, and handling precautions are necessary in order to control these hazards. Gas cylinders should be stored in upright positions and immobilized by chains or other means to prevent them from being knocked over. If the cylinders fall over and are damaged the can be turned into rocket! Other important precautions to take include:
Compressed Air - Compressed air may be used instead of drilling mud when there is no risk of encountering high-pressure, permeable formations or formations containing water. It has the advantages of faster drilling and of not having to recondition the circulating mud. The drilling dust is discharged from the "blooey line" and may be blown across the working area to cause a respiratory hazard; dust particles may cause eye injuries.
Directional Drilling - Directional drilling occurs when a contractor intentionally drills a well that is out of plumb. Surface conditions may dictate that a drilling rig cannot be erected over the formation to be explored or, as in offshore operations, the rig may be costly enough that multiple formations should be explored from a central drilling position. Directional drilling is achieved by a number of different methods. Directional tools include downhole hydraulic turbine motors, jet deflector bits, bent subs, flexible joints, or, most common in past years, whipstocks.
Redrilling - The redrilling of a well takes place when well depth must be extended. (The existing formation may not be productive and the well may be extended to tap a lower formation.) In some instances, the prior drilling operation may have stopped for reasons associated with annulus collapse, damaged casing, lost drilling string, or blowout.
Workers servicing or maintaining machines or equipment may be seriously injured or killed if hazardous energy is not properly controlled. Injuries resulting from the failure to control hazardous energy during maintenance activities can be serious or fatal!
Failure to control hazardous energy may result in electrocution, burns, crushing, cutting, lacerating, amputating, or fracturing body parts, and others. For example, an effective Lockout/Tagout Program would have prevented the following accidents:
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