AseptSoft Core Documentation
AseptSoft Core Documentation
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Fluid

A Fluid (formally a Fluid Flow State) defines a type of fluid that flows through the piping system in Fluidstream Simulations. Each fluid has a name, color, aggregation state, priority, and flow direction setting.

💡 In pharmaceutical terms: Fluids represent the actual media flowing through your plant — WFI (Water for Injection), CIP caustic, CIP acid, product, steam, nitrogen, and more. Each fluid gets a unique color so you can instantly see on the P&ID which medium is flowing through every pipe.

📋 Properties

Property

Type

Description

Name

Text

Unique identifier for the fluid (e.g., "WFI", "CIP Caustic", "Steam")

Color

Color

The color used to paint pipes and connectors when this fluid flows through them

Aggregation

Selection

Physical state of the fluid (see table below)

Priority

Integer

Determines which fluid wins when multiple fluids meet at a junction (higher priority wins)

Reversed Flow

Yes/No

Whether this fluid flows in the reverse direction relative to normal pipe flow

Custom Attributes

Collection

User-defined attribute key-value pairs

🌡️ Aggregation States

The aggregation state describes the physical form of the fluid:

Aggregation

What It Means

Examples

Liquid

The fluid is in a liquid state

WFI, CIP Acid, CIP Caustic, Product, Buffer Solution

Gas / Vapor

The fluid is in a gaseous or vapor state

Steam, Nitrogen, Compressed Air, CO₂

Not specified

Aggregation state has not been defined (treated as liquid by default)

Use this when the state is not relevant

⚖️ Priority System

When multiple fluids converge at a junction or mixing point, the Priority value determines which fluid takes precedence. The fluid with the higher priority value wins and is displayed downstream.

🏭 Pharma example: During a CIP sequence, both WFI and CIP Caustic may be present at different points in the piping. If CIP Caustic has a priority of 2 and WFI has a priority of 1, the simulation will show CIP Caustic when both are present at the same junction.

This is important when a pipe receives flow from multiple sources with different fluids — the priority system ensures a deterministic visual result.

🔄 Reversed Flow

When Reversed Flow is enabled, the fluid is shown flowing in the opposite direction of the normal pipe flow. This is useful for:

  • 🏭 CIP return lines — return flow traveling back to the CIP skid

  • Backflow scenarios — representing reverse flow conditions

  • Counter-current heat exchangers — media flowing in opposite directions

🔗 How Fluids Work with States

Fluids are connected to the system through State fluid responses:

State Fluid Response

Effect on Fluid

Allow fluid to pass

Fluid passes through the item unchanged

Block fluid

Fluid is blocked — cannot pass through

Unknown

No fluid information — neutral

Change into an existing fluid stream → Fluid

Incoming fluid is transformed into the specified Fluid

Generate a new fluid stream → Fluid

A new Fluid is created at this point (e.g., a WFI supply source)

📖 How To: Define Fluids for Your Module

  1. Open Module Data — Navigate to the Data panel in the Module Ribbon and open the Module Data window.

  2. Go to the Fluids tab — Select the Fluids section.

  3. Create a new Fluid — Click "Create new" and give it a clear name (e.g., "WFI", "CIP Caustic").

  4. Choose a color — Pick a distinctive color that will be clearly visible on the P&ID. Use industry conventions where possible (blue for water, gray for steam, etc.).

  5. Set the aggregation — Choose "Liquid" or "Gas / Vapor" based on the physical state.

  6. Assign a priority — Higher numbers win when fluids conflict at a junction. Give process-critical fluids higher priority.

  7. Enable Reversed Flow (if needed) — For return lines and backflow scenarios.

  8. Connect to States — In your State definitions, use "Generate a new fluid stream" or "Change into an existing fluid stream" to connect valves and sources to this fluid.

🏭 Example: Typical Fluids in a Biotech Facility

Fluid Name

Color

Aggregation

Priority

Reversed Flow

Typical Use

WFI

Blue

Liquid

1

No

Water for Injection — final rinse, dilution

CIP Acid

Orange

Liquid

2

No

Acid cleaning solution (e.g., phosphoric acid)

CIP Caustic

Purple

Liquid

2

No

Alkaline cleaning solution (e.g., NaOH)

CIP Return

Dark Blue

Liquid

1

Yes

Return flow from CIP circuit back to skid

Product

Gold

Liquid

3

No

Active pharmaceutical product or buffer

Steam

Light Gray

Gas / Vapor

3

No

SIP sterilization steam

Nitrogen

Yellow

Gas / Vapor

1

No

Inert blanketing gas

Compressed Air

Light Green

Gas / Vapor

1

No

Instrument air, valve actuation

Condensate

Cyan

Liquid

1

Yes

Steam condensate return

💡 Tip: Establish a color convention early in your project and document it. Consistent fluid colors across all modules make P&IDs much easier to read during reviews and commissioning.