Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Flame Velocity
Definition(s)
Flame Velocity
Speed at which a flame front travels into an unburned combustible mixture.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global StandardsFlame-proof
Definition(s)
Flame-proof
A type of protection of electrical apparatus in which an enclosure will withstand an internal explosion of a flammable mixture which has penetrated into the interior, without suffering damage and without causing ignition, through any joints or structural openings in the enclosure, of an external explosive atmosphere consisting of one or more of the gases or vapors for which it is designed. This type of protection is referred to as "d." NOTE: See also enclosure, explosion-proof. Source: API RP 14F, Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class 1, Division 1 and Division 2 Locations, Fifth Edition, July 2008. Global StandardsFlame-resistant Clothing
Definition(s)
Flame-resistant Clothing
Clothing that is treated with chemicals and/or made of material that resists igniting if the responder is exposed to fire or heat. NOTE 1 Flame-resistant clothing helps to protect responders, for instance, such as those responders in the igniter boat during ISB. NOTE 2 The clothing should be cleaned, maintained, and regularly inspected in accordance with the manufacturer’s instructions. NOTE 3 Some flame-resistant clothing may lose its protective qualities after repeated or improper cleanings. Wearing any flammable clothing over flame-resistant clothing negates the flame-resistant protection. NOTE 4 Flame-resistant clothing should be selected in accordance with 29 CFR Subpart I (Personal Protective Equipment), Section 1910.132 (General Requirements). Source: API RP 98, Personal Protective Equipment Selection for Oil Spill Responders, First Edition, August 2013. Global StandardsFlame-Retention Device
Definition(s)
Flame-Retention Device
Device used to prevent flame lift-off from a flare burner.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global StandardsFlame-Retention Device
Device used to prevent flame blow off from a flare burner. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsFlameproof
Definition(s)
Flameproof
A type of protection of electrical apparatus in which an enclosure will withstand an internal explosion of a flammable mixture which has penetrated into the interior, without suffering damage and without causing ignition, through any joints or structural openings in the enclosure, of an external explosive atmosphere consisting of one or more of the gases or vapors for which it is designed. This type of protection is referred to as “d.”
- NOTE: See also enclosure, explosionproof.
Flameproof Enclosure “d”
Definition(s)
Flameproof Enclosure “d”
Type of protection in which the parts capable of igniting an explosive gas atmosphere are provided with an enclosure which can withstand the pressure developed during an internal explosion of an explosive mixture and which prevents the transmission of the explosion to the explosive gas atmosphere surrounding the enclosure. Source: IEC 60079-14:2013, Explosive atmospheres – Part 14: Electrical installations design, selection and erection, Edition 5.0, November 2013. Global StandardsFlammable
Definition(s)
Flammable
Capable of igniting easily, burning intensely or having a rapid rate of flame spread. Source: API Recommended Practice 14FZ, Recommended Practice for Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class I, Zone 0, Zone 1, and Zone 2 Locations, Second Edition, May 2013. Global Standards Source: API RP 14F, Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class 1, Division 1 and Division 2 Locations, Fifth Edition, July 2008. Global StandardsFlammable
Capable of igniting easily, burning intensely, or spreading flame rapidly. Source: API RP 14G, Recommended Practice for Fire Prevention and Control on Fixed Open-type Offshore Production Platforms: Upstream Segment, Fourth Edition, April 2007. Global Standards API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global StandardsFlammable (Explosive) Limits
Definition(s)
Flammable (Explosive) Limits
The lower and upper percentages by volume of concentration of gas in a gas-air mixture that will form an ignitable mixture (reference NFPA 497). API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global StandardsFlammable Gas
Definition(s)
Flammable Gas
Substance that exists exclusively in the gaseous state at normal atmospheric pressure and temperature and is capable of igniting and burning when mixed with air (oxygen) in the proper proportion and subjected to a source of ignition. Source: API RP 98, Personal Protective Equipment Selection for Oil Spill Responders, First Edition, August 2013. Global StandardsFlammable Gas (Gas Properties)
Gas or vapour which, when mixed with air in a certain proportion, will form an explosive atmosphere. NOTE For the purposes of this standard, the term "flammable gas" includes flammable vapours. Source: IEC 60079-29-1, Explosive atmospheres – Part 29-1: Gas detectors – Performance requirements of detectors for flammable gases. Global StandardsFlammable Gas (or Vapour)
Gas or vapour which, when mixed with air in certain proportions, will form an explosive gas atmosphere. Source: IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas. Global StandardsFlammable Limits
Definition(s)
Flammable (Explosive) Limits
The lower and upper percentages by volume of concentration of gas in a gas-air mixture that will form an ignitable mixture. (See NFPA 325M.) Source: API RP 14G, Recommended Practice for Fire Prevention and Control on Fixed Open-type Offshore Production Platforms: Upstream Segment, Fourth Edition, April 2007. Global StandardsFlammable Liquid
Definition(s)
Flammable Liquid (Class MIII, and Class IC liquids)
A liquid having a flash point below l00°F (37.8°C) and having a vapor pressure not exceeding 40 lb per sq. in. absolute (276 kilopascals) at l00°F (37.8°C). Flammable (Class 1) liquids are subdivided into Classes IA, IB, and IC. (See NFPA 30.) Source: API RP 14G, Recommended Practice for Fire Prevention and Control on Fixed Open-type Offshore Production Platforms: Upstream Segment, Fourth Edition, April 2007. Global StandardsFlammable liquid
Any liquid having a flashpoint below 100 °F (373 °C). Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global Standards Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsFlammable Liquid
Liquid capable of producing a flammable vapour under any foreseeable operating conditions. Source: IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas. Global StandardsFlammable Liquid
A liquid having a flash point below 100oF., (37.8oC) and having a vapor pressure not exceeding 40 lb. per sq. in. (absolute) (176 kPa) at 100oF (37.8oC) and shall be known as Class I liquid. Class I Liquids shall be subdivided as follows: Class IA shall include those having flash points below 73oF., (22.8oC.) and having a boiling point below 100oF., (37.8oC.). Class IB shall include those having flash points below 73oF., (22.8oC.) and having a boiling point at or above 100oF., (37.8oC.). Class IC shall include those having flash points at or above 73oF., (22.8oC.) and below 100oF., (37.8oC.). Source: Petroleum Safety Orders--Drilling and Production, Definitions, California Code of Regulations, 8 CCR § 6505, December 2012. RegulationsFlammable Liquid
"Flammable liquid" means any liquid having a flashpoint below 100°F. (37.8°C.), except any mixture having components with flash-points of 100°F. ( 37.8°C) or higher, the total of which make up ninety-nine (99) percent or more of the total volume of the mixture. Flammable liquids shall be known as Class I liquids. Class I liquids are divided into three classes as follows:- Class IA shall include liquids having flashpoints below 73°F. (22.8°C.) and having a boiling point below 100°F. (37.8°C.). Example: LPG.
- Class IB shall include liquids having flashpoints below 73°F. (22.8°C.) and having a boiling point at or above 100°F. (37.8°C.) Example: Acetone, Methyl Ethyl Ketone.
- Class IC shall include liquids having flashpoints at or above 73°F. (22.8°C.) and below 100°F. (37.8°C.). Example: Turpentine.6
Flammable Liquid (Class I Liquid)
Definition(s)
Flammable Liquid (Class I Liquid)
Any liquid that has a closed-cup flash point below 37.8 °C (100 °F), as determined by the test procedures and apparatus specified in NFPA 30. See 5.2. Flammable (Class I) liquids are subdivided into Classes IA, IB, and IC (reference NFPA 30. API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global StandardsFlammable Material
Definition(s)
Flammable Material (Flammable Substance)
Material which is flammable of itself, or is capable of producing a flammable gas, vapour or mist. Source: IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas. Global StandardsFlammable Materials
Definition(s)
Flammable Materials
As used in this Code, includes all fluids which will support combustion. Refer to NFPA 704 for guidance on classifying fluids in 6.3.4.- NOTE: Some regulatory documents include separate definitions of flammables and combustibles based on their flash point. In this document flammable is used to describe both and the flash point, boiling point, auto ignition temperature or other properties are used in addition to better describe the hazard.
Flammable, Highly Volatile Liquid
Definition(s)
Flammable, Highly Volatile Liquid
See highly volatile liquid. API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global StandardsFlange
Definition(s)
Flange
Protruding rim, with holes to accept bolts and having a sealing mechanism, used to join pressure-containing equipment with dimensions specified in this specification. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global StandardsFlange
Protruding rim, with holes to accept bolts and having a sealing mechanism, used to join pressure-containing equipment with dimensions specified in this standard.
Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global StandardsFlange
Protruding rim with holes to accept bolts and having a sealing mechanism used to join pressure-containing equipment, with dimensions specified in this International Standard. Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global StandardsFlange
Protruding rim, with holes to accept bolts and having a sealing mechanism, used to join pressure-containing equipment together by bolting to another flange. Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global StandardsFlange
A protruding rim with holes to accept bolts and having a sealing mechanism wed to join pressure containing equipment, and with dimensions specified by API. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsFlange Joint
Definition(s)
Flange Joint
Mechanical joint with face flanges for which the bolt circle and face dimensions conform to a recognized standard. Source: ISO 14692-1:2017, Petroleum and natural gas industries — Glass-reinforced plastics (GRP) piping — Part 1: Vocabulary, symbols, applications and materials, Second Edition, August 2017. Global StandardsFlange, Blind
Definition(s)
Flange, Blind
A flange with no center bore, used to close off completely a flanged end or outlet connection. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsFlange, Loose
Definition(s)
Flange, Loose
A flange, as manufactured, not intended to be made integral with another piece of API equipment. There are blind, threaded, spacer, welding neck, studded, or other connected adapter flanges. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsFlange, Threaded
Definition(s)
Flange, Threaded
A flange having a sealing face on one side and female had on the other for the purpose of joining flanged connections to threaded connections. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsFlange, Welding Neck
Definition(s)
Flange, Welding Neck
A flange with a neck on the side opposite the sealing face prepared with a bevel to weld to corresponding pipe or transition pieces. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsFlange-Type Coupling
Definition(s)
Flange-Type Coupling
Coupling having two flanges joined by threaded fasteners.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global StandardsFlange-Type Coupling
A coupling having two flanges joined by bolts. Source: API RP 16Q, Recommended Practice for Design, Selection, Operation and Maintenance of Marine Drilling Riser Systems, First Edition, November 1993 (Reaffirmed August 2001). Global Standards Source: API SPEC 16R, Specification for Marine Drilling Riser Couplings, Exploration and Production Department, First Edition, January 1997. Global Standards Source: ISO 13624-1:2009, Petroleum and natural gas industries – Drilling and production equipment – Part 1:Design and operation of marine drilling riser equipment. Global StandardsFlank
Definition(s)
Flank (or Side)
Surface of a thread that connects the crest with the root. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global StandardsFlare
Definition(s)
Flare
Device or system used to safely dispose of relief gases in an environmentally compliant manner through the use of combustion. Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsFlare
The stack, pit, or device, or location where waste or excess flammable gases and vapors are burned in the atmosphere. Source: Petroleum Safety Orders--Drilling and Production, Definitions, California Code of Regulations, 8 CCR § 6505, December 2012. RegulationsFlare Burner
Definition(s)
Flare Burner
Part of the flare where fuel and air are mixed at the velocities, turbulence, and concentration required to establish and maintain proper ignition and stable combustion.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards