exported
necessary
pipe elbow
IRI:
http://www.inf.ufrgs.br/ontologies/copi#Pipeelbow
Generated on 2026-04-16
Natural Language Definition
EN
A pipe elbow is a pipe that has curved geometry enabling directional changes in pipe runs between 0 and 135 degrees.
PT-BR
Um cotovelo de tubulação é uma tubulação que possui geometria curva permitindo mudanças direcionais em trechos de tubulação entre 0 e 135 graus.
Formal Axioms
Semi-formal (Aristotelian)
Every pipe elbow is a pipe that has curved geometry and enables directional change capacity between 0 and 135 degrees.
First-Order Logic Theory
Loading…
▸ Stored override
∀x (PipeElbow(x) → (Pipe(x) ∧ ∃g(CurvedGeometry(g) ∧ hasGeometricProperty(x,g)) ∧ ∃p(DirectionalChangeCapacity(p) ∧ hasProperty(x,p))))
OWL 2 / Turtle
@prefix copi: <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix : <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix bfo: <http://purl.obolibrary.org/obo/> .
@prefix iof-core: <https://spec.industrialontologies.org/ontology/construct/> .
@prefix iof-av: <https://spec.industrialontologies.org/ontology/annotation/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix qudt: <http://qudt.org/schema/qudt/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix apv: <http://inf.ufrgs.br/ontologies/apv#> .
### COPI — Core Ontology for Petroleum Installations
### Class module: PipeElbow
<https://www.inf.ufrgs.br/ontologies/copi>
rdf:type owl:Ontology ;
dcterms:title "Core Ontology for Petroleum Installations (COPI)"@en ;
dcterms:title "Ontologia Core para Instalações de Petróleo (COPI)"@pt-br ;
dcterms:description "BFO/IOF-Core conformant ontology of equipment classes for petroleum production plants, developed using the five-step RDL enrichment method."@en ;
skos:scopeNote "Material artifacts (bfo:material_entity) that (i) are part of a petroleum production plant, and (ii) bear at least one function whose realization involves the transport (e.g. production and injection), processing (separation and other processes), control, monitoring, measurement, containment or offloading of material or energy."@en ;
skos:scopeNote "Artefatos materiais (bfo:material_entity) que (i) fazem parte de uma planta de produção de petróleo, e (ii) possuem ao menos uma função cuja realização envolve o transporte (p. ex. produção e injeção), processamento (separação e outros processos), controle, monitoramento, medição, contenção ou escoamento de material ou energia."@pt-br ;
skos:scopeNote "COPI provides high-level equipment categories defined by function to demonstrate the defined-class mechanism. Equipment subtypes are annotated with references to CFIHOS and PCA RDL terms. COPI is not a reference data library; organizations should use CFIHOS, PCA RDL, or ISO 14224 for comprehensive equipment classification."@en ;
skos:scopeNote "COPI fornece categorias de alto nível de equipamentos definidas por função para demonstrar o mecanismo de classe definida. Os subtipos de equipamentos são anotados com referências aos termos do CFIHOS e do PCA RDL. COPI não é uma biblioteca de dados de referência; organizações devem utilizar o CFIHOS, o PCA RDL ou a ISO 14224 para classificação abrangente de equipamentos."@pt-br ;
owl:versionInfo "1.1.0" ;
owl:imports <https://spec.industrialontologies.org/ontology/core/Core/> ;
owl:imports <http://purl.obolibrary.org/obo/bfo/2020/bfo.owl> ;
dcterms:creator "Nicolau Oyhenard dos Santos"@en ;
dcterms:contributor "Cauã Antunes" ;
dcterms:contributor "Haroldo Rojas" ;
dcterms:contributor "Rafael Petry" ;
dcterms:contributor "Régis Romeu" ;
dcterms:contributor "Mara Abel" ;
dcterms:isPartOf <https://inf.ufrgs.br/projetos/OntoKG> ;
dcterms:publisher "Universidade Federal do Rio Grande do Sul (UFRGS)"@en ;
dcterms:license <https://creativecommons.org/licenses/by/4.0/> ;
dcterms:created "2026-04-08"^^xsd:date ;
dcterms:modified "2026-10-08"^^xsd:date ;
apv:GlobalMinLanguageCoverage "en pt-br" ;
apv:ClassURIFormationRule "https://www[.]inf[.]ufrgs[.]br/ontologies/copi/(COPI_[0-9]{7}|[A-Z][A-Za-z0-9]*)" ;
apv:ClassMinAnnotationCoverage "rdfs:label https://spec.industrialontologies.org/ontology/annotation/naturalLanguageDefinition" .
iof-av:naturalLanguageDefinition rdf:type owl:AnnotationProperty ;
apv:MinAnnotationLength 20 .
### Identity-giving function
:COPI_0000529 rdf:type owl:Class ; # FluidConductionFunction
rdfs:subClassOf iof-core:DesignedFunction ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:allValuesFrom :COPI_0000530 # FluidConductionProcess
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:someValuesFrom :COPI_0000530 # FluidConductionProcess
] ;
rdfs:label "fluid conduction function"@en ;
rdfs:label "função de condução de fluido"@pt-br .
### Process type
:COPI_0000530 rdf:type owl:Class ; # FluidConductionProcess
rdfs:subClassOf :COPI_0000003 ; # MomentumTransfer
rdfs:label "fluid conduction process"@en ;
rdfs:label "processo de condução de fluido"@pt-br .
:COPI_0000003 rdf:type owl:Class . # MomentumTransfer
:COPI_0000530 # FluidConductionProcess
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasInput ;
owl:someValuesFrom :COPI_0000037 # PortionOfFluid
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasSpecifiedOutput ;
owl:someValuesFrom :COPI_0000037 # PortionOfFluid
] .
### Equipment universal: PipeElbow
:COPI_0000323 rdf:type owl:Class ; # PipeElbow
rdfs:subClassOf :COPI_0000321 ; # Pipe
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasFunction ; # Object branch (MaterialArtifact/Assembly/Object/FiatObjectPart)
owl:someValuesFrom :COPI_0000529 # FluidConductionFunction
] ;
rdfs:label "pipe elbow"@en ;
rdfs:label "cotovelo de tubulação"@pt-br ;
iof-av:naturalLanguageDefinition "A pipe elbow is a pipe that has curved geometry enabling directional changes in pipe runs between 0 and 135 degrees."@en ;
skos:definition "A pipe elbow is a pipe that has curved geometry enabling directional changes in pipe runs between 0 and 135 degrees."@en ;
iof-av:naturalLanguageDefinition "Um cotovelo de tubulação é uma tubulação que possui geometria curva permitindo mudanças direcionais em trechos de tubulação entre 0 e 135 graus."@pt-br ;
iof-av:semiFormalNaturalLanguageAxiom "Every pipe elbow is a pipe that has curved geometry and enables directional change capacity between 0 and 135 degrees."@en ;
iof-av:firstOrderLogicAxiom "∀x (PipeElbow(x) → (Pipe(x) ∧ ∃g(CurvedGeometry(g) ∧ hasGeometricProperty(x,g)) ∧ ∃p(DirectionalChangeCapacity(p) ∧ hasProperty(x,p))))"@en ;
iof-av:isPrimitive "true"^^xsd:boolean ;
iof-av:primitiveRationale "Using necessary conditions for this constructive type protects against false positives under OWA. Any curved piping component would be forcibly classified as a pipe elbow under equivalent axioms, including specialized equipment like coiled tubing, serpentine heat exchanger tubes, or custom manifold sections that contain curved passages but should not be asserted into the standard pipe elbow maintenance category."@en ;
skos:definition "[ISO 15926-4] A <PIPE ELBOW> is a <PIPING COMPONENT> and an <ELBOW> that is intended to make a change in the direction of a pipe run between 0 and 135 degrees"@en ;
skos:definition "[POSC Caesar] An 'elbow' and an 'artefact' that is intended to make a change in the direction of a pipe run between 0 and 135 degrees."@en .
# Disjointness: PipeElbow and PipeTee
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000323 :COPI_0000325 ) . # PipeElbow, PipeTee
# Disjointness: PipeElbow and PipeReducer
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000323 :COPI_0000324 ) . # PipeElbow, PipeReducer
Axiomatization Decision Log
1
Identity-Giving Function
Function class
FluidConductionFunction
⊑ DesignedFunction
Realized in
FluidConductionProcess
⊑ MomentumTransfer
A pipe elbow's identity-giving function is the same as any pipe component - to conduct fluid through its internal passage. The elbow geometry is a structural feature that enables this conduction function in directional changes, but does not constitute a distinct function type.
2
Genus Determination
Pipe
From the source hierarchies, pipe elbow is classified as both a PIPING COMPONENT and an ELBOW. The most specific appropriate genus is 'pipe' since a pipe elbow is fundamentally a specialized pipe segment with curved geometry. The enriched pipe class already exists in our ontology with FluidConductionFunction, making it the correct direct superclass.
3
Necessary Parts
No necessary parts recorded (concept may be primitive at this level).
These parts are necessary for any pipe elbow regardless of specific angle, radius, or end connection type. More specific parts (like particular end connection types) vary by subtype and should be modeled at those levels.
4
Process Participation Signature ⟨I, O, T⟩
Inputs (I)
PortionOfFluid
— any phase
Outputs (O)
PortionOfFluid
— same composition, redirected flow
Transformation (T)
directional change without composition alteration
A pipe elbow conducts fluid while changing its flow direction. The fluid composition and phase remain unchanged, but the flow vector is altered according to the elbow's geometry.
5
Axiom Mode Decision
Necessary conditions only
— modelled as a primitive universal
(⊑, SubClassOf). Identity is grounded in designed
function and cannot be reduced to a property checklist.
Using necessary conditions for this constructive type protects against false positives under OWA. Any curved piping component would be forcibly classified as a pipe elbow under equivalent axioms, including specialized equipment like coiled tubing, serpentine heat exchanger tubes, or custom manifold sections that contain curved passages but should not be asserted into the standard pipe elbow maintenance category.
Disjointness Axioms
pipe tee
pipe reducer
C1: pipe tee, pipe reducer. These have incompatible process signatures: pipe elbow enables directional change with single inlet/outlet, while tee/cross enable branching/merging with multiple inlets/outlets, and reducers change cross-sectional area rather than direction.
Cross-Standard Observations
Both ISO 15926 and POSC Caesar provide consistent definitions emphasizing the directional change function and the 0-135 degree angular constraint. The standards align well on the geometric and functional characteristics.
