AseptSoft Core Documentation
AseptSoft Core Documentation
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Fluidstream Simulations

Fluidstream Simulations overlay your P&ID drawing to visualize where fluid flows when starting from Sources and Engineering Items like tanks — through pipes and open valves.

The system reads the geometry and neighborhood of items in your P&ID to determine where fluid advances. It uses a breadth-first graph traversal algorithm that propagates fluid state from source nodes through connected pipe segments, respecting valve logic and connector routing rules.

Access: Toggle simulations from the Module Ribbon → Simulations panel → Show Path / Hide Path button.

💊 Pharma Example: Verifying CIP Coverage for WFI Spray Devices

In a pharmaceutical facility, you need to confirm that a CIP (Clean-In-Place) cycle delivers WFI (Water for Injection) to every spray ball inside a vessel. Here is how Fluidstream Simulations help:

  1. Open your P&ID containing the CIP supply loop, the WFI Source, and the target vessel with spray devices

  2. Assign the WFI source its Fluid Parameter (e.g., "WFI") with a distinctive color (e.g., light blue)

  3. Set the CIP Step so that all valves along the CIP route are in their Open State and the vessel inlet valve is open

  4. Toggle Show Path from the ribbon — the simulation will paint every pipe segment that WFI reaches in light blue

  5. Visually verify that the colored overlay reaches every spray ball inside the vessel. If a spray device remains unpainted, trace upstream to find the closed valve or missing connection

  6. Use Select Upstream Path on an unreached spray ball to identify exactly which path is broken

This workflow replaces hours of manual pipe-tracing with an instant visual confirmation that your CIP cycle has full coverage.

🔬 How To: Run Your First Fluid Simulation

Follow these steps to run a fluid simulation on any P&ID drawing:

Step

Action

Details

1

Open your P&ID

Load the drawing that contains your piping layout, valves, and instruments

2

Verify Sources

Ensure at least one Source is placed on the drawing and assigned a Fluid Parameter with a visible color

3

Configure valve States

Open the module and set States for your Engineering Items (e.g., Open, Closed, Generating) for the desired Step

4

Launch the simulation

Go to the Module Ribbon → Simulations panel → click Show Path

5

Read the overlay

Colored pipes = fluid is flowing. Uncolored overlay pipes = no fluid has reached them

6

Trace issues

Click an unpainted segment and use Select Upstream Path or Select Downstream Path to diagnose why fluid does not reach it

7

Iterate

Switch Steps, toggle valve States, or adjust your drawing — the simulation updates in real time

Tip: If the simulation looks incorrect after editing geometry, click Clear Cache on the ribbon to rebuild the connectivity graph from scratch. For details on how the graph is built, see Fluidstream Mapping Strategies.

⚙️ How It Works

  1. Graph Construction — AseptSoft builds a unified graph from all entities in the P&ID. Each Engineering Item, pipe segment, and Source becomes a node, with edges representing physical connections. The algorithms that discover these connections are described in detail on the Fluidstream Mapping Strategies page

  2. Fluid Propagation — Starting from fluid sources and generator valves, the simulation propagates fluid state through the graph using breadth-first traversal

  3. Valve Logic — At each Engineering Item, the active State in the current Step determines whether fluid passes, is blocked, is transformed, or is generated

  4. Visual Overlay — Pipe segments touched by fluid are colored with the fluid's color (defined by the Fluid Parameter). Untouched segments remain on a separate overlay layer

🔀 Fluid Competition

When two different fluid streams approach the same pipe segment from opposite directions, both stop at the meeting point — they do not mix. If one stream is later cut off (e.g., a valve closes), the other stream advances to occupy the freed segments.

🔄 Real-Time Updates

The simulation updates automatically when you make changes — switching Steps, toggling valve states, or modifying the P&ID geometry.

🧪 Fluid Response

Each Engineering Item has a Fluid Response determined by its active State. The possible responses are:

Fluid Response

Behavior

Allow

Fluid passes through the item unchanged

Deny

Fluid is blocked — nothing passes. If fluid arrives from multiple sides, none advance past the item

Unknown

Behaves like Allow, but can generate warnings. Automatically used when an item has no active State (a gray/unset valve). Warnings indicate the item may be unintentionally reached by fluid

Change Into (Fluid)

Fluid passes through but is transformed into a different fluid. Used primarily for filters — e.g., a filter receiving "Water" outputs "Purified Water"

Generate (Fluid)

The item becomes a fluid source, outputting the specified fluid in all directions regardless of incoming fluid. Used primarily for filled tanks

📊 Percentage-Based Fluid Response

When a State activates a percentage, the Engineering Item's effective Fluid Response depends on both the State's Fluid Response and its Zero Fluid Response (the response at 0%):

Active Percent

Effective Response

100%

Same as the State's Fluid Response

1% – 99%

The higher-priority response between the State's Fluid Response and Zero Fluid Response (priority: Generate > Change Into > Unknown > Allow > Deny)

0%

Same as the State's Zero Fluid Response

Example 1 — Tank: State "Water" has Fluid Response = Generate Water, Zero Fluid Response = Allow. At 100%: generates water. At 0%: allows incoming fluid (empty tank). Between 1-99%: generates water (Generate has higher priority than Allow).

Example 2 — Valve: State "Open Percentual" has Fluid Response = Allow, Zero Fluid Response = Deny. At 100%: allows fluid. At 0%: blocks fluid (fully closed). Between 1-99%: allows fluid (Allow has higher priority than Deny).

🔌 Connectors Fluid Response

Connectors (Flow States) behave as child elements of an Engineering Item. When an item has visible Connectors, the fluid simulation routes flow through specific connector paths rather than treating the item as a single pass-through node.

Output Pairs

Each Connector has an Output Pairs list defining which other Connectors on the same parent item can receive fluid forwarded from it:

  • Fluid entering through a Connector is forwarded only to the Connectors listed in its Output Pairs

  • The active State of each destination Connector determines whether the fluid continues or is blocked

Example — Four-Way Valve with Connectors: Top (Inward), Bottom, Left, Right.

  • Top's Output Pairs: [Bottom, Left, Right] — incoming fluid from Top is forwarded to all three

  • Bottom/Left/Right's Output Pairs: [Top] — incoming fluid is forwarded only to Top

  • Since Top is Inward, fluid arriving at Bottom/Left/Right is forwarded to Top but blocked (Inward only accepts, does not emit)

See the Connectors page for details on configuring Output Pairs and directionality.

🎛️ Ribbon Controls

The Module Ribbon → Simulations panel provides:

Button

Action

Show Path / Hide Path

Toggle fluidstream visualization on/off

Clear Cache

Rebuild the fluid graph from scratch (useful after P&ID geometry changes)

Select Upstream Path

Select an item, then highlights all nodes/pipes that feed fluid into it

Select Downstream Path

Select an item, then highlights all nodes/pipes that receive fluid from it

Path selection highlights the traced path in cyan for easy identification on the P&ID.

📐 Layers

Layers represent virtual spaces in AutoCAD on which shapes and pipes are placed. The fluidstream simulation is layer-sensitive — you can control which layers participate in fluid flow.

Restrict Layers

Access the layer restriction window from the Module Ribbon → Simulations panel. Disabling a layer means that any shape or pipe on that layer will not receive or forward fluid.

Overlay Layers

AseptSoft creates temporary overlay geometry to visualize fluid flow:

Layer

Purpose

AseptSoft FluidFlow

Colored overlay lines where fluid is actively flowing

AseptSoft Empty FluidFlow

Overlay lines for pipe segments not yet touched by fluid

These overlay lines duplicate the original Lines/Polylines/Arcs connecting assets. They are temporary and destroyed when the simulation ends.

Tip: You can customize the appearance of these layers (LineWeight, Pattern) in AutoCAD's layer manager. Use the LWEIGHT command and enable "Display Lineweight" for improved visualization.

🎨 Symbol Geometry Painting

When Symbols have static geometry groups defined in the Symbol Editor, the fluidstream simulation can also paint the interior geometry of Engineering Items — not just the connecting pipes. This applies fluid colors to the symbol geometry clones, giving you a complete visual picture of which components are wetted by fluid.