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 neighbourhood of items in your P&ID to determine where fluid advances and displays the result as a colored overlay directly on the drawing.

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

ℹ️ Note: The Fluid Stream is configured during the First Time Setup, which is handled by the AseptSoft development team. This page explains how the simulation works and how you can understand, verify, and troubleshoot it. For practical troubleshooting steps, see Fluidstream Troubleshooting.

🧠 How AseptSoft Determines Fluid Flow

For us humans, it is easy to look at a P&ID and see how objects are connected — where the fluid comes from and where it should go. Even without being told what a clamp is, we can look at two parallel lines and instantly understand that fluid flows from one end to the other. AseptSoft, however, cannot simply "look at the screen" and recognise which objects are neighbours.

So how does it work? AseptSoft knows the full geometry of your P&ID. All you need to do is tell it when an object is too far away to be considered connected. Most of the time, connected objects are close together — but not always. That is where a few key settings come in.

These settings help AseptSoft decide:

• ✅ When fluid should flow through an object to its neighbours

• ❌ When fluid should not continue (e.g., the gap is too large or the object type blocks flow)

To make that decision, AseptSoft relies on a set of geometric mapping rules — each one checking for a specific pattern. These are described in detail on the Fluidstream Mapping Strategies page.

📐 Three Pillars of the Fluid Stream

The Fluid Stream simulation depends on three layers of configuration:

When all three are properly tuned, the Fluid Stream works automatically across all your PIDs. If you plan to work on similar PIDs beyond the current project, AseptSoft can reuse the same settings and rules, so the Fluid Stream works out of the box.

✅ The Fluid Stream in Action

When the Fluid Stream is working perfectly, you can open and close valves, fill tanks, and enable fluid sources. AseptSoft then visualizes — right on the P&ID — how the fluid automatically follows the lines according to your configured process.

Here are examples of a properly working Fluid Stream:

💡 Tip: All settings and rules are saved in your Environment. They are correctly tuned during the First Time Setup and apply across all your PIDs.

🔬 How To: Run Your First Fluid Simulation

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

💡 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.

💊 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 (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

⚙️ How It Works

1. Graph Construction — AseptSoft builds a connectivity 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

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). 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:

📊 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%):

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.

📐 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.

Understanding layers is critical because some lines in a P&ID are not pipe lines. For example, wall lines, instrumentation signal lines, and construction lines should not carry fluid. By disabling these layers, you tell AseptSoft to ignore them during mapping.

How to Configure Layers

1. Open the Module Ribbon → Simulations panel

2. Click the Layer Settings button to open the layer restriction window

3. For each AutoCAD layer, you can set:

⚠️ Important: Before disabling a layer, check the impact by using AutoCAD's Q-Select (Quick Select) to see which entities are on that layer. Disabling the wrong layer can break fluid connectivity.

Overlay Layers

AseptSoft creates temporary overlay geometry to visualize fluid flow:

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.

🎛️ Ribbon Controls

The Module Ribbon → Simulations panel provides:

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

🗺️ Neighbours Map (Fluid Map)

The Neighbours Map (also known as the Fluid Map) is a diagnostic visualization that shows you exactly how AseptSoft has connected all entities — before even running a fluid simulation. It is invaluable for verifying and troubleshooting the mapping configuration.

How to Display the Neighbours Map

Click Show Neighbours Map from the Module Ribbon → Simulations panel. When activated, you will see colored lines and text appearing on your P&ID:

💡 Tip: To identify a specific entity among many, select it in AutoCAD and use the LIST command — this displays the entity's Handle value, which you can match against the red n-prefixed labels in the Neighbours Map.

The Neighbours Map shows a proof of connectivity: if you see a blue line between two entities, it means AseptSoft will allow fluid to flow between them (subject to valve states). If there is no blue line, no fluid can pass between those entities.

🔗 Related Pages

• Fluidstream Mapping Strategies — Covers all mapping algorithms used to build the fluid connectivity graph, including tolerance settings and configuration

• Fluidstream Troubleshooting — Common problems and how to solve them

• Fluid — Define fluid types and colors

• Sources — Fluid origin points

• Engineering Items — Items that interact with fluid flow

• State — Determines fluid response behavior

• Symbol Editor — Defines symbol geometry for fluid painting

• Module Ribbon — Simulations panel controls

• Connectors — Flow routing through Engineering Items

• First Time Setup — Initial configuration including classification and mapping