Hidden Failure or Dormant Failure

Hidden Failure or Dormant Failure

Definition(s)

Hidden Failure or Dormant Failure

Hidden failures (dormant) are failures that are not detected by themselves and that need a specific action (e.g. periodic test) to be identified. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards
Revealed Failure

Revealed Failure

Definition(s)

Revealed Failure

Revealed failures are failures that are detected by the system itself as soon as they occur. Failures detected by the diagnostic test of a logic solver are also considered as revealed failures.. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  
Non Fail-Safe System

Non Fail-Safe System

Definition(s)

Non Fail-Safe System

Non-fail safe is a safety system where there remains the possibility of dangerous failures. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards
Fail-Safe System

Fail-Safe System

Definition(s)

Fail-Safe System

The fail-safe system is based on a design which has reduced the effect of potentially dangerous failures as far as practically possible. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards
Safe Failures or Spurious Trip Failures

Safe Failures or Spurious Trip Failures

Definition(s)

Safe Failures or Spurious Trip Failures

Safe failures (spurious trip failures) are failures that have the potential to trigger the safety function when it is not needed. A single safe failure is generally not sufficient to actually trip unexpectedly a redundant safety system (e.g. 2 safe failures are needed for a 2-out-of-3 voting system). Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  
Dangerous Failures (or Unsafe Failures)

Dangerous Failures (or Unsafe Failures)

Definition(s)

Dangerous Failures (or Unsafe Failures)

Dangerous failures (or unsafe failures) are failures that have the potential to prevent the safety system from achieving its safety function when there is a true demand. A single dangerous failure is generally not sufficient to prevent a redundant safety system from performing its safety function (e.g. two dangerous failures are needed for a 2-out-of-3 voting system). Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards
Non-Dangerous Failures

Non-Dangerous Failures

Definition(s)

Non-Dangerous Failures

Non-dangerous failures are failures that do not have an immediate effect on the safety function, i.e. do not prevent the safety system from achieving its safety function or do not cause spurious trips. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards
Manual Shutdown

Manual Shutdown

Definition(s)

Manual Shutdown

The machinery is stopped by an intended action of the operator (locally or from the control room). Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards
Spurious Trip

Spurious Trip

Definition(s)

Spurious Trip

Unexpected shutdown results from error(s) in the control/monitoring system or error(s) imposed on the control/monitoring system originating from the environment or people.For some equipment, “spurious stop” is defined as a failure mode that can be either a real trip or a spurious trip as defined above depending on cause. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  
Disposition

Disposition

Definition(s)

Disposition

Action taken in accordance with the applicable specification with regard to a defect in a length of OCTG. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Discontinuity

Discontinuity

Definition(s)

Discontinuity (or Flaw or Imperfection)

Irregularity in the product, such as a lap, seam, pit and lamination. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Detector

Detector

Definition(s)

Detector or Detector Shoe

Scanning shoe carrying one or more transducers, used to protect transducers from mechanical damage. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  

Detector

Detector is the sensing element which measures the gas concentration. Source: IMO MSC.1/Circ.1370, Guidelines for the design, construction and testing of fixed hydrocarbon gas detection systems, 22 June 2010, International Maritime Organization. Regulatory Guidance  
Demagnetization

Demagnetization

Definition(s)

Demagnetization

Process of removing part or all of the residual magnetism from OCTG. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
DC-Field

DC-Field

Definition(s)

DC-Field

Residual or active magnetic field induced by direct current. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Real Trip

Real Trip

Definition(s)

Real Trip

The shutdown is effectuated as a result of a monitored (or calculated) value in the control system exceeding a pre-set limit. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  
Trip

Trip

Definition(s)

Trip

The shutdown is activated automatically by the control/monitoring system. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  

Trip

shutdown of machinery from normal operating condition to full stop Note 1 to entry: Two types of shutdown can be identified: a) Trip: the shutdown is activated automatically by the control/monitoring system. • Real trip: the shutdown is activated as a result of a monitored (or calculated) value in the control system exceeding a pre-set limit. • Spurious trip: unexpected shutdown resulting from failure(s) in the control/monitoring system or error(s) imposed by on control/monitoring system originating from the environment or people. b) Manual shutdown: the machinery is stopped by an intended action of the operator (locally or form the control room). Note 2 to entry: Sometimes statements like “equipment trip” or “spurious trip” can be misleading terminology used for failures causing (rotating) equipment shutdown, especially when it is treated as failure mode in reliability data or modelling. A failure mechanism (see Table B.2 of ISO 14224[15]) can be of various types (e.g. mechanical, instrument) and should not be mixed with the term failure modes (of which one is spurious trip). Failure modes are not necessarily instrument-related failures, but could be mechanical failures. See for example failure modes in Table B.6 of ISO 14224[15] for rotating equipment. [SOURCE: ISO 14224] Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global Standards
Cut

Cut

Definition(s)

Cut (Noun)

Gouge or distortion in two or more thread crests in a line, either parallel to the pipe axis or at an angle across the threads. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  

Cut

Incision without removal of metal caused by a sharp object. Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global Standards  
Crest

Crest

Definition(s)

Crest

Top of a thread. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Couplant

Couplant

Definition(s)

Couplant

Material (usually a liquid) used between an ultrasonic transducer and the test specimen to assist transmission of ultrasonic sound waves between them. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Shutdown

Shutdown

Definition(s)

Shutdown

Shutdown of machinery refers to the situation when the machinery is shut down from normal operating condition to full stop. Two types of shutdown exist: trip and shutdown. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  
Contour-Grind

Contour-Grind

Definition(s)

Contour-Grind or Radius-Grind (verb)

Grind to remove sharp edges and/or abrupt changes in the wall thickness around imperfections or areas of exploratory grinding. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Contour

Contour

Definition(s)

Contour (verb)

Taper gradually by filing or grinding to remove abrupt changes in the wall thickness. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Classification

Classification

Definition(s)

Classification

Action taken to categorize a length of new OCTG based on conformance with the contracted inspection requirements. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  

Classification

A service provided by Classification Societies which establishes and administers standards, known as Rules, for the design, construction and periodic survey of merchant ships and other marine and offshore structures. Classification certifies adherence to these Rules, and means that a vessel possesses the structural and mechanical fitness required for its intended service. Source: International Association of Drilling Contractors, Appendix 2 to Health, Safety and Environment Case Guidelines for Offshore Drilling Contractors, Issue 3.3.2, February 2010. IADC Guidelines  

Classification

A service which comprises the development of independent technical standards for vessels - class rules and standards, and to verify compliance with the rules and standards throughout the vessels' life. Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global Standards
WO

WO

Definition(s)

WO

Work order. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  
Circular Magnetization

Circular Magnetization

Definition(s)

Circular Magnetization or Circumferential Magnetization

Production of a magnetic field in a pipe wall or coupling such that the magnetic field is oriented circumferentially. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Circular Magnetic Field

Circular Magnetic Field

Definition(s)

Circular Magnetic Field or Circumferential Magnetic Field

Magnetic field in or surrounding a current-carrying conductor, or OCTG, such that the magnetic field is oriented circumferentially within the wall of the OCTG. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
TTR

TTR

Definition(s)

TTR

Top Tension Factor Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards

TTR

Top Tensioned Riser Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards

TTR

Time to repair. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards  
Chock

Chock

Definition(s)

Chock

Block or wedge used beneath a length of pipe so that it cannot roll. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Chatter

Chatter

Definition(s)

Chatter

Wavy surface of the thread flank, root, crest, or chamfer, caused by a vibrating cutter insert. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  
Chamfer

Chamfer

Definition(s)

Chamfer

Conical surface at the end of pipe having round or buttress threads. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards