Safety is paramount when it comes to any hot tapping operations on equipment in the petroleum and petrochemicals industry. Although the severity of incidences cannot be erradicated, following the strict guidelines of processes can help reduce probability.
Hot Tapping Definitions
1 - Acute hazard
Capable of causing effects occuring from exposure over a short time, usually a few minutes or hours. An acute exposure can result in short-term or long-term health benefits.
2 - Exposure limit
For chemical agents are a measure of the maximum airborne concentration limits for toxic substances to which workers may be exposed without protection (for example, respirators). Exposure limits are usually expressed in parts per million or milligrams per cubic meter for a defined period of time. Material Safety Data Sheets (MSDSs) from the manufacturer or supplier of the material should list exposure limits.
3 - Hydrogen blister
Bulge in steel caused by high pressure molecular hydrogen trapped at an internal flaw within steel.
4 - IDLH
The NIOSH traditional definition is the maximum concentration of an air contaminant from which one could escape within 30 min. without a respirator and without experiencing any escape-impairing or irreversible health effects.
5 - Inerting
The process of eliminating the potential for a flammable atmosphere by using an inert gas such as nitrogen, carbon dioxide or steam (water vapor) to displace oxygen required for ignition.
6 - Lockout
The placement of a lockout device on an energy isolating device, in accordance with an established procedure, ensuring that the energy isolating device and the equipment being controlled cannot be operated until the lockout device is removed”.
7 - Lower flammable limit (LFL)
The minimum concentration of a vapor in air (or other oxidant) below which propagation of flame does not occur on contact with an ignition source. The lower flammable limit is usually expressed as a volume percentage of the vapor in air. Sometimes called Lower Explosive Limit (LEL).
8 - Particulate
Inhalable materials considered by ACGIH to be hazardous when deposited anywhere in the respiratory tract.
9 - Qualified person
A person designated by the employer who, by possession of a recognized degree, certificate, or professional standing, or by extensive knowledge, training and experience, has successfully demonstrated ability to identify and solve or resolve problems relating to the subject matter, the work, or the project and, when required, is properly licensed in accordance with federal, state, or local laws and regulations.
10 - Risk assessment
The identification and analysis, either qualitative or quantitative, of the likelihood and outcome of specific events or scenarios with judgements of probability and consequences.
11 - Risk-based analysis
A review of potential needs based on a risk assessment.
12 - Tagout
The placement of a tagout device on an energy isolating device, in accordance with an established procedure, to indicate that the energy isolating device and the equipment being controlled may not be operated until the tagout device is removed.
13 - Threshold limit values (TLV®s)
Exposure limits published annually by the American Conference of Governmental Industrial Hygienists in Threshold Limit Values and Biological Exposure Indices. (TLV® is a registered trademark of the American Conference of Governmental Industrial Hygienists).
14 - Upper flammable limit (UFL)
The maximum concentration of a vapor in air (or other oxidant) above which propagation of flame does not occur on contact with an ignition source. The upper flammable limit is usually expressed as a volume percentage of the vapor in air. Sometimes called the Upper Explosive Limit (UEL). In popular terms, a mixture containing a percentage of flammable vapor above the UFL is too “rich” to burn and one below the LFL is too “lean” to burn.
15 - Vapor
The gaseous state of materials; vapor release requires elevated temperature for materials which are liquid or solid at ambient temperature. Materials can burn only when in their vapor state.
For more information on how to reduce hazards during hot tapping processes, take a look at our safety checklist available to download for free here.
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