Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Test Block
Definition(s)
Test Block
Special precision blocks, used as standards to verify calibration of an inspection instrument. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global StandardsMach Number
Definition(s)
Mach Number
Actual fluid velocity divided by the velocity at which sound waves propagate through the fluid at the associated temperature.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global StandardsMach Number
Ratio of a fluid’s velocity, measured relative to some obstacle or geometric figure, divided by the speed at which sound waves propagate through the fluid. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsLiquid Seal or Water Seal
Definition(s)
Liquid Seal or Water Seal
Device that directs the flow of relief gases through a liquid (normally water) on the path to the flare burner, used to protect the flare header from air infiltration or flashback, to divert flow, or to create back pressure for the flare header. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsLift
Definition(s)
Lift
Actual travel of the disc from the closed position when a valve is relieving. 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 StandardsLateral
Definition(s)
Lateral
Section of pipe connecting the outlet(s) of single-source relief device(s) to a header where other sources are tied in.- NOTE: The relief flow in a lateral is always from a single source, whereas the relief flow in a header can be from either single or multiple sources simultaneously.
Lateral
Section of pipe from outlet flange(s) of single-source relief device(s) downstream of a header connection where relief devices from other sources are tied in.- NOTE: The relief flow in a lateral is always from a single source, whereas the relief flow in a header can be from either single or multiple sources simultaneously.
Lateral
“Lateral” means a portion of a directional well past the point where the well bore has been intentionally departed from the vertical. Source: Oil and Gas, New Mexico Administrative Code Title 19, Chapter 15, January 2013. RegulationsKnockout Drum
Definition(s)
Knockout Drum
Vessel in the effluent handling system designed to remove and store liquids. 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 StandardsJet Fire
Definition(s)
Jet Fire
Turbulent diffusion flame resulting from the combustion of a fuel continuously released with significant momentum in a particular direction. 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 StandardsJet Fire (JF)
Turbulent diffusion flame resulting from the combustion of a fuel continuously released with momentum in a particular direction. Source: ISO 13702:2015, Petroleum and natural gas industries — Control and mitigation of fires and explosions on offshore production installations — Requirements and guidelines, Second Edition, August 2015. Global StandardsJet Fire
Fire created when a leak from a pressurized system ignites and forms a burning jet.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global StandardsJet Fire
Fire created when a leak from a pressurized system ignites and forms a burning jet.- NOTE: A jet fire can impinge on other equipment, causing damage.
Hydrate
Definition(s)
Hydrate
Solid, crystalline compound of water and a low-boiling-point gas (e.g. methane and propane), in which the water combines with the gas molecule to form a solid. 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 StandardsHuddling Chamber
Definition(s)
Huddling Chamber
Annular chamber located downstream of the seat of a pressure-relief valve, which assists the valve to lift. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsHeat Release
Definition(s)
Heat Release
Total heat liberated by combustion of the relief gases based on the lower heating value. 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 StandardsGround Flare
Definition(s)
Ground Flare
Non-elevated flare.- NOTE: A ground flare is normally an enclosed flare but can also be a ground multi-burner flare or a burn-pit.
Flashback
Definition(s)
Flashback
Phenomenon occurring in a flammable mixture of air and gas when the local velocity of the mixture becomes less than the flame velocity, causing the flame to travel back through the mixture.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global StandardFlashback
Phenomenon occurring in a flammable mixture of air and gas when the local velocity of the combustible mixture becomes less than the flame velocity, causing the flame to travel back to the point of mixture. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsFlare Header
Definition(s)
Flare Header
Piping system that collects and delivers the relief gases to the flare. 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 Burner or Flare Tip
Definition(s)
Flare Burner or Flare Tip
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, Fifth Edition, January 2007 (Addendum May 2008). 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. RegulationsFlame-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 StandardsEnclosed Flare
Definition(s)
Enclosed Flare
Enclosure with one or more burners arranged in such a manner that the flame is not directly visible. 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 StandardsEntity
Definition(s)
Entity
'Entity' means any natural or legal person or any group of such persons. Source: DIRECTIVE 2013/30/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 12 June 2013 on safety of offshore oil and gas operations and amending Directive 2004/35/EC. LegislationEntity
“Entity” means a person, association of persons, firm, company or co- operative society, by whatsoever name called or referred to, other than a dealer or distributor, and engaged or intending to be engaged in refining, processing, storage, transportation, distribution, marketing, import and export of petroleum, petroleum products and natural gas including laying of pipelines for transportation of petroleum, petroleum products and natural gas, or laying, building, operating or expanding city or local natural gas distribution network or establishing and operating a liquefied natural gas terminal. Source: The Petroleum and Natural Gas Regulatory Board Act, 2006, No. 19 of 2006, India, amended as of May 2013. LegislationEntiteit (Dutch)
„entiteit”: iedere natuurlijke persoon, rechtspersoon of groepering van deze personen;.Entité (French)
'«entité», toute personne physique ou morale ou tout groupement de telles personnes;.Enhed (Danish)
»enhed«: en fysisk eller juridisk person eller en gruppe af sådanne personer.Entidad (Spanish)
«entidad»: toda persona física o jurídica o agrupación de esas personas;.Entitate (Romanian)
'entitate” înseamnă orice persoană fizică sau juridică sau grupare de astfel de persoane;.Einrichtung (German)
„Einrichtung“ jede natürliche oder juristische Person oder jede Vereinigung solcher Personen.οντότητα (Greek)
«οντότητα» σημαίνει οποιοδήποτε φυσικό ή νομικό πρόσωπο ή οποιαδήποτε ομάδα τέτοιων προσώπων.Entità (Italian)
«entità»: qualsiasi persona fisica o giuridica ovvero qualsiasi forma di associazione di tali persone.Podmiot (Polish)
„podmiot” oznacza osobę fizyczną lub osobę prawną lub grupę takich osób.Entidade (Portuguese)
«Entidade», uma pessoa singular ou coletiva ou agrupamento de pessoas coletivas.Enhet (Swedish)
enhet: en fysisk eller juridisk person eller en grupp av sådana personer..Toimijalla (Finnish)
’toimijalla’ tarkoitetaan kaikkia luonnollisia tai oikeushenkilöitä tai tällaisten henkilöiden ryhmää;.Subjekt (Slovenian)
„subjekt“ pomeni vsako fizično ali pravno osebo ali vsako skupino takih oseb;.Subjekt (Slovak)
„subjekt“ je každá fyzická alebo právnická osobu alebo skupina takýchto osôb;.Subjektas (Lithuanian)
subjektas – fizinis ar juridinis asmuo arba tokių asmenų grupė;.Jogalany (Hungarian)
„jogalany”: bármely természetes vagy jogi személy vagy ilyen személyek csoportja;.Entità (Maltese)
entità‧ tfisser kwalunkwe persuna fiżika jew ġuridika jew kwalunkwe grupp ta’ persuni bħal dawn;.Vienība (Latvian)
“vienība” ir jebkura fiziska vai juridiska persona vai jebkura šādu personu grupa;.Ettevõtja (Estonian)
„ettevõtja”– füüsiline või juriidiline isik või selliste isikute rühm;.Subjektem (Czech)
„subjektem“ jakákoli fyzická nebo právnická osoba nebo jakékoli jejich seskupení;;.субект (Bulgarian)
'„субект“ означава всяко физическо или юридическо лице или група от такива лица;.Competent Authority
Definition(s)
Competent Authority
“Competent Authority” means any person or authority authorized by the Central Government, by notification the Official Gazette, to perform the functions of the Competent Authority under this act and different persons or authorities may be authorized to perform all or any of the functions of the Competent Authority under this Act in the same area or different area specified in the notification. Source: The Petroleum Mineral Pipelines (Acquisition of Right of User in Land) Act, 1962, Act No. 50 of 1962, India, as amended as of May 2013. LegislationCompetent Authority
'Competent Authority' means the public authority, appointed pursuant to this Directive and responsible for the duties assigned to it in this Directive. The competent authority may be comprised of one or more public bodies. Source: DIRECTIVE 2013/30/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 12 June 2013 on safety of offshore oil and gas operations and amending Directive 2004/35/EC. LegislationCompetent Authority
“Competent authority” means authority, appointed by the Central Government for implementation of these rules. Source: Petroleum and Natural Gas (Safety in Offshore Operations) Rules, 2008, India, 18th June 2008. RegulationsBevoegde autoriteit (Dutch)
„bevoegde autoriteit”: de overheidsinstantie die aangesteld is op grond van deze richtlijn en belast is met de haar krachtens deze richtlijn opgedragen taken. De bevoegde autoriteit kan uit een of meer overheidsorganen bestaan.1Autorité compétente (French)
«autorité compétente», les pouvoirs publics désignés en vertu de la présente directive et responsables des tâches qui lui sont assignées par la présente directive. L’autorité compétente peut se composer d’un ou de plusieurs organismes publics.1Kompetent myndighed (Danish)
»kompetent myndighed«: den offentlige myndighed, der er udnævnt i henhold til dette direktiv, og som er ansvarlig for de opgaver, der er pålagt den i dette direktiv. Den kompetente myndighed kan bestå af et eller flere offentlige organer.1Autoridad competente (Spanish)
«autoridad competente»: la autoridad pública designada en virtud de la presente Directiva y responsable de las funciones que le asigna la presente Directiva. La autoridad competente podrá constar de uno o de varios organismos públicos.1Autoritate competentă (Romanian)
„autoritate competentă” înseamnă autoritatea publică desemnată în temeiul prezentei directive și care este responsabilă pentru atribuțiile conferite prin prezenta directivă. Autoritatea competentă poate fi compusă dintr-unul sau mai multe organisme.1Zuständige Behörde (German)
„zuständige Behörde“ die Behörde, die gemäß dieser Richtlinie benannt wird und für die Aufgaben verantwortlich ist, die ihr mit dieser Richtlinie übertragen werden. Die zuständige Behörde kann eine oder mehrere öffentliche Stellen umfassen.1αρμόδια αρχή (Greek)
«αρμόδια αρχή» σημαίνει τη δημόσια αρχή που διορίζεται σύμφωνα με την παρούσα οδηγία και είναι υπεύθυνη για τα καθήκοντα που της ανατίθενται δυνάμει της παρούσας οδηγίας. Η αρμόδια αρχή μπορεί να απαρτίζεται από έναν ή περισσότερους δημόσιους φορείς.1Autorità competente (Italian)
«autorità competente»: l’autorità pubblica nominata a norma della presente direttiva e responsabile dei compiti assegnati dalla presente direttiva. L’autorità competente può essere costituita da uno o più organismi pubblici.1Właściwy organ (Polish)
„właściwy organ” oznacza organ publiczny wyznaczony na podstawie niniejszej dyrektywy i pełniący obowiązki przydzielone mu w niniejszej dyrektywie. Właściwy organ może być złożony z jednej lub większej liczby jednostek publicznych.1Autoridade competente (Portuguese)
«Autoridade competente», a autoridade pública designada nos termos da presente diretiva responsável pelas funções que lhe são atribuídas pela presente diretiva. A autoridade competente pode ser constituída por um ou mais organismos públicos.1Behörig myndighet (Swedish)
behörig myndighet: den myndighet som har utsetts enligt detta direktiv och som ansvarar för de uppgifter som den tilldelats genom detta direktiv. Den behöriga myndigheten kan bestå av ett eller flera offentliga organ.1Toimivaltaisella viranomaisella (Finnish)
’toimivaltaisella viranomaisella’ tarkoitetaan tämän direktiivin nojalla nimitettyä viranomaista, joka vastaa tässä direktiivissä sille osoitetuista tehtävistä. Toimivaltainen viranomainen voi muodostua yhdestä tai useammasta julkisesta elimestä.1Pristojni organ (Slovenian)
„pristojni organ“ pomeni javni organ, imenovan v skladu s to direktivo in odgovoren za naloge, dodeljene s to direktivo. Pristojni organ je lahko sestavljen iz enega ali več javnih organov.1Príslušný orgán (Slovak)
„príslušný orgán“ je orgán verejnej moci určený podľa tejto smernice zodpovedný za úlohy, ktoré mu sú pridelené v tejto smernici. Príslušný orgán sa môže skladať z jedného alebo viacerých orgánov verejnej moci.1Kompetentinga valdžios institucija (Lithuanian)
kompetentinga valdžios institucija – pagal šią direktyvą paskirta valdžios institucija, atsakinga už pagal šią direktyvą jai pavestas pareigas. Kompetentingą valdžios instituciją gali sudaryti viena ar daugiau viešųjų įstaigų.1Illetékes hatóság (Hungarian)
„illetékes hatóság”: az ezen irányelv szerint kijelölt és az ezen irányelv szerint ráruházott feladatokért felelős hatóság. Az illetékes hatóságot egy vagy több közjogi szerv alkothatja.1Awtorità kompetenti (Maltese)
‧awtorità kompetenti‧ tfisser l-awtorità pubblika, nominata skont din id-Direttiva u li hija responsabbli għad-dmirijiet mogħtija lilha f'din id-Direttiva. L-awtorità kompetenti tista’ tkun magħmula minn korp pubbliku wieħed jew aktar.1Kompetentā iestāde (Latvian)
“kompetentā iestāde” ir publiska iestāde, kas iecelta, ievērojot šo direktīvu, un kas ir atbildīga par uzdevumiem, kuri tai uzticēti ar šo direktīvu. Kompetentā iestāde var ietvert vienu vai vairākas publiskas iestādes.1Pädev asutus (Estonian)
„pädev asutus”– vastavalt käesolevale direktiivile määratud ja talle käesoleva direktiivi alusel omistatud ülesannete eest vastutav avaliku sektori asutus. Pädev asutus võib hõlmata üht või mitut avaliku sektori asutust.1Příslušným orgánem (Czech)
„příslušným orgánem“ orgán veřejné moci určený podle této směrnice a pověřený výkonem úkolů, které pro něj stanoví tato směrnice. Příslušný orgán může být tvořen jedním nebo více orgány veřejné správy.1компетентен орган (Bulgarian)
„компетентен орган“ означава публичният орган, определен съгласно настоящата директива и отговарящ за изпълнението на задълженията, възложени му с настоящата директива. Компетентният орган може да се състои от една или повече публични структури.1Competent Authority
Competent authority means an organization authorized by the Administration to perform functions required by this Code. Source: IMO Resolution MSC.307(88), International Code for Application of Fire Test Procedures, 2010 (2010 FTP Code), 3 December 2010, International Maritime Organization. Regulatory GuidanceAcceptable
Definition(s)
Acceptable
'Acceptable', in relation to a risk, means a level of risk for which the time, cost or effort of further reducing it would be grossly disproportionate to the benefits of such reduction. In assessing whether the time, cost or effort would be grossly disproportionate to the benefits of further reducing the risk, regard shall be had to best practice risk levels compatible with the undertaking. Source: DIRECTIVE 2013/30/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 12 June 2013 on safety of offshore oil and gas operations and amending Directive 2004/35/EC LegislationAcceptable
For the purpose of interpreting the standards referred to in subsection (2), “acceptable” means appropriate. Source: Oil and Gas Occupational Safety and Health Regulations, SOR/87-612, Canada, current to April 29, 2013. RegulationsTranslations
Enrichment
Definition(s)
Enrichment
Process of adding assist gas to the relief gas. 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 StandardsElevated Flare
Definition(s)
Elevated Flare
Flare where the burner is raised high above ground level to reduce radiation intensity and to aid in dispersion. 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 StandardsDispersion
Definition(s)
Dispersion
Dilution of a vent stream or products of combustion as the fluids move through the atmosphere. 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 StandardsDetonation
Definition(s)
Detonation
Explosion in which the flame front is advancing at or above the speed of sound in the unburned combustible mixture.- NOTE: See deflagration (3.1.23).
Detonation
Explosion in which the flame-front of a combustible medium is advancing at or above the speed of sound. cf. deflagration (3.22). Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsDestruction Efficiency
Definition(s)
Destruction Efficiency
Mass percent of the original combustible vapor that is no longer present in the combustion products.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global StandardsDestruction Efficiency
Mass fraction of the fluid vapour that can be oxidized or partially oxidized. NOTE For a hydrocarbon, this is the mass fraction of carbon in the fluid vapour that oxidizes to CO or CO2. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsDesign Pressure
Definition(s)
Design Pressure
Purchaser nominated maximum pressure to which a piping system is designed to operate at the nominated design temperature (Tdes) and for the nominated design life (Ldes).- Note: 1 to entry: Pdes is typically considered as a sustained pressure, though an additional Pdes occasional can also be nominated. Pdeswill be selected based on the maximum operating pressure plus a purchaser selected uplift.
- to accommodate pressure uncertainty,
- to avoid triggering of pressure safety devices,
- to match the rating of attached piping or equipment and d) to provide a design margin for other purposes.
Design Pressure
For each design condition, maximum fluid temperature that can be reached during service. 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 StandardsDesign Pressure (of a piping component)
The pressure at the most severe condition of coincident internal or external pressure and temperature (minimum or maximum) expected during service. It is the same as the design pressure defined in ASME B31.3 and other code sections and is subject to the same rules relating to allowances for variations of pressure or temperature or both.
Source: API 570, Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems, Fourth Edition, February 2016, with Addendum May 2017. Global StandardsDesign Pressure
Pressure, together with the design temperature, used to determine the minimum permissible thickness or physical characteristic of each component, as determined by the design rules of the pressure design code.- NOTE: The design pressure is selected by the user to provide a suitable margin above the most severe pressure expected during normal operation at a coincident temperature, and it is the pressure typically specified on the purchase order. The design pressure is equal to or less than the MAWP (the design pressure can be used as the MAWP in cases where the MAWP has not been established).
Design Pressure
Maximum sustained difference between internal pressure and external pressure during normal operations, referred to a specified elevation. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsDesign Pressure
Maximum difference between internal pressure and external pressure that is unlikely to be exceeded during the life of the riser, referred to a specified reference height.- NOTE: Design pressure is often named maximum allowable pressure or rated working pressure or maximum allowable.
- EXAMPLE: Design pressure is the maximum pressure considering shut-in pressure at the wellhead (seabed) or at the top of the riser with subsea valves open, maximum well fracturing pressure, maximum well injection pressure, maximum surge pressure or maximum well kill pressure.
Design Pressure
Maximum pressure for which the system or component was designed for continuous usage. Source: API SPEC 17F, Specification for Subsea Production Control Systems, Second Edition, December 2006 (Reaffirmed April 2011). Global StandardsDesign Pressure
Maximum pressure ratings for a pipe or vessel based on its specified minimum yield strength (SMYS), diameter and wall thickness, operation zone, and weld joint type.. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsDesign Pressure
Minimum or maximum pressure, inclusive of operating pressure, surge pressure including shut-in pressure where applicable, vacuum conditions and static pressure head. Source: API SPEC 17J, Specification for Unbonded Flexible Pipe, Third Edition, July 2008. Global StandardsDesign Pressure
Pressure, together with the design temperature, used to determine the minimum permissible thickness or physical characteristic of each component, as determined by the design rules of the pressure-design code. NOTE The design pressure is selected by the user to provide a suitable margin above the most severe pressure expected during normal operation at a coincident temperature, and it is the pressure specified on the purchase order. The design pressure is equal to or less than the MAWP (the design pressure can be used as the MAWP in cases where the MAWP has not been established). Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsDesign Pressure
Design pressure means the hydrostatic pressure for which each structure or appliance assumed watertight in the intact and damage stability calculations is designed to withstand. . <Chapter II-1, regulation 2>. Source: IMO Resolution MSC.216(82), amendments to the International Convention for the Safety of Life at Sea, 1974, as amended, 8 December 2006, International Maritime Organization. LegislationDeflagration
Definition(s)
Deflagration
Explosion in which the flame front is advancing at less than the speed of sound in the unburned combustible mixture.- NOTE See detonation (3.1.26).
Deflagration
Explosion in which the flame-front of a combustible medium is advancing at less than the speed of sound. cf. detonation (3.25). Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsCorrected Hydrotest Pressure
Definition(s)
Corrected Hydrotest Pressure
Hydrostatic test pressure multiplied by the ratio of stress value at upset temperature to the stress value at test temperature.- NOTE :1 See 4.2.2 and C.7.
- NOTE : 2 In this definition, the hydrostatic test pressure is that specified by the pressure design code, whether or not the equipment has actually been hydrostatically tested.
Corrected Hydrotest Pressure
Hydrostatic test pressure multiplied by the ratio of stress value at design temperature to the stress value at test temperature. NOTE See 4.3.2. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsConventional Pressure-Relief Valve
Definition(s)
Conventional Pressure-Relief Valve
Spring-loaded pressure-relief valve whose operational characteristics (set pressure, closing pressure, and relieving capacity) are directly affected by changes in the backpressure.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards