Draw a flow sheet

flowsheet() lays out a resolved S223 or WaTr model as a process flow sheet. Streams are lines, not boxes: each connection is drawn between the equipment it joins, coloured by its medium. A connection with properties is labelled with them; its name appears as a tooltip in SVG output.

Draw a model

from plumb import Model, connect, flowsheet
from plumb.qudt import quantity_kinds, units
from plumb.watr import LevelSensor, Pump, Tank, enums
from plumb.watr.drinking_water import (
    ChlorinationStage,
    ClarificationStage,
    RapidSandFiltrationStage,
)

values = enums.values
model = Model("urn:example:flowsheet#")
with model:
    with model.system("plant"):
        intake = Pump("intake-pump")
        clarifier = ClarificationStage("clarifier")
        sand_filter = RapidSandFiltrationStage("sand-filter")
        chlorination = ChlorinationStage("chlorine-contact")
        clearwell = Tank("clearwell", has_role=[values.Role_Storage])
        sludge_tank = Tank("sludge-holding")

raw = connect(intake, clarifier.inlet, name="raw-water")
connect(clarifier.clarified_water, sand_filter.inlet, name="settled-water")
filtered = connect(sand_filter.filtered_water, chlorination.inlet, name="filtered-water")
connect(chlorination.outlet, clearwell, name="disinfected-water")
connect(clarifier.sludge, sludge_tank, name="sludge", medium=values.Fluid_Sludge)
model["plant"].boundary(intake.port("river-intake", direction="in"))

raw.quantity("raw-turbidity", 18.0, unit=units.NTU, kind=quantity_kinds.Turbidity)
raw.sensor("raw-flow", kind=quantity_kinds.VolumeFlowRate, unit=units.M3_PER_DAY)
filtered.sensor("filter-turbidity", kind=quantity_kinds.Turbidity, unit=units.NTU)
clearwell.sensor("clearwell-level", kind=quantity_kinds.Length, unit=units.M,
                 sensor_class=LevelSensor)
intake.actuator("intake-speed", kind=quantity_kinds.Frequency, unit=units.HZ)

flowsheet(model, title="Surface-water plant")

The model is resolved before drawing, so deferred connections appear on the connection points the solver chose. What you see:

• Unit operations (equipment with has_process or has_treatment_objective) list those inside their box. Other equipment, such as pumps and tanks, shows its name and type.

• Sensors are ISA-style bubbles (FT, AT, LT, …) and actuators are dashed ZC boxes, drawn beside the line or equipment they belong to. The quantity they observe or command is shown on the instrument rather than repeated as a stream property.

• Systems are dashed clusters. A system’s boundary point that has no connection becomes a feed or product terminal.

Change the layout

direction="TB" stacks the train top to bottom instead of left to right, which suits long trains on a narrow page:

flowsheet(model, direction="TB", properties=False, legend=False)

Draw a saved model

flowsheet() reads the RDF view of the model, not the Python objects you authored, so a Turtle file loaded back in draws the same sheet. Loading picks the WaTr and drinking-water packages from the file’s owl:imports:

from plumb import Model

model.save("plant.ttl")
loaded = Model.from_graph("plant.ttl")
flowsheet(loaded, title="Loaded from plant.ttl")

A ResolvedModel from model.compile() works too, and skips the resolve step.

Simplify or export

sheet = flowsheet(model, properties=False, instruments=False, legend=False)
sheet

sheet.save("plant.svg") writes SVG; .png and .pdf work too, and .dot writes the Graphviz source in sheet.source. Rendering needs Graphviz’s dot on PATH; the source does not.