The WaTr vocabulary

plumb.watr is generated from WaTr v0.3.0.rc1, vendored unmodified as ontology/watr-0.3.0rc1.ttl. Terms may change before 0.3.0.

Equipment, process, objective, and role

Each answers a different question about a unit:

Question	Relation	Example
What is it?	rdf:type	watr:GravityThickener
What does it do?	watr:hasProcess	watr:Process-Settling
What is it for?	watr:hasTreatmentObjective	watr:TreatmentObjective-Thickening
What is its place in this system?	s223:hasRole	watr:Role-Primary

A sedimentation tank and a gravity thickener share a process, settling, but not an objective: one clarifies water, the other thickens sludge. A role depends on the installation.

Processes and objectives are classes, used directly as values; they serialize as class IRIs. Roles are enum values. See Set processes, objectives, and roles.

Class defaults

Some processes and objectives follow from the equipment class: every GravityThickener settles to thicken. WaTr’s ClassDefaultsRule infers these in RDF, and generated constructors apply the same defaults. A default is skipped when you supply that term or a subclass of it.

Where	Defaults applied
Python constructor	most specific term only
ClassDefaultsRule (validate(), or from_graph(infer=True))	every implied term
from_graph() without infer	none; the graph is kept as written

ProcessObjectiveRule adds the objective a process implies (Process-Chlorination implies disinfection). It runs only as a SHACL rule. No rule supplies a role.

Media and constituents

WaTr models freshwater with an H₂O constituent, and seawater, brackish water, and brine with H₂O and NaCl. A shared constituent makes media compatible at a connection. It does not assert equal composition.

Fluid-Sludge is a Mix-Fluid of water and solids, not a kind of Fluid-Water, so a sludge port does not accept a water-only connection.

The bundled shapes also check percentage compositions:

• CompositionPercentageShape flags constituent percentages that exceed 100%.

• CompositionComplementRule infers a single missing percentage from the rest.

Names shared with S223

plumb.watr contains the S223 classes it imports as well as WaTr’s own. When both define a name, WaTr’s keeps it and S223’s gets a suffix: Pump is watr:Pump and Pump_2 is s223:Pump. WaTr’s pump accepts any Mix-Fluid, including sludge; S223’s admits only water, oil, or refrigerant. Check Pump.meta.iri when it matters.

WaTr’s enum additions, such as Fluid_Sludge and Role_Backwash, sit alongside the S223 values in plumb.watr.enums.