Datacor’s latest releases of Fathom 14 and Arrow 11 introduce a capability that simplifies a familiar design task: converting Control Valves into equivalent passive flow devices. The new Control Valve Sizing Tool automates this conversion so engineers can move quickly from sizing to finalizing system components.

Why Control Valve Sizing Matters

In many models, Control Valve junctions are used as a design tool for sizing passive devices that rely on resistance to control how flow is distributed through a system. In Fathom, this resistance is defined hydraulically; in Arrow, it is defined pneumatically.

Once the design point is established, those Control Valves often need to be converted into Orifices or Valves so the final model reflects the intended physical components. Traditionally, this required iterative adjustments, multiple simulation runs, and manual calculation and data entry. The Control Valve Sizing Tool is designed to streamline that process.

A Faster Way to Convert Control Valves

With the Control Valve Sizing Tool, engineers can:

• Select one or many Control Valves.
• Choose whether to convert them to Orifices or Valves.
• Apply the conversion using Edit > Morph Control Valves To.

A window allows engineers to select which Control Valves will be included in the morph operation. Model Output must exist before performing the conversion so the tool has the information needed to calculate the equivalent passive device.

How It Works in Fathom 14

In Fathom 14, conversions follow a consistent set of rules:

• Convert to Orifice:
  The Control Valve becomes a Sharp-Edged Orifice, and the orifice diameter is calculated to match the pressure drop across the Control Valve.
• Convert to Valve:
  The Control Valve becomes a Valve using the Cv loss model, with an equivalent Cv calculated and applied.

Engineers can review the calculated values in the Valve Summary, including Cv and Equivalent Orifice Area, before finalizing the conversion.

How It Works in Arrow 11

In Arrow 11, the tool uses models suited to systems where resistance is defined pneumatically:

• Convert to Orifice:
  The Control Valve becomes an Orifice using a Cd (Exit) loss model with an assumed Cd = 0.6. The diameter is calculated to match the behavior of the Control Valve.
• Convert to Valve:
  The Control Valve becomes a Valve using a K factor loss model, with an equivalent K factor calculated.

Flexible Scenario Management

The Control Valve Sizing Tool supports different workflows. Engineers can choose to create a Child Scenario ahead of time if they want to preserve the original model before making changes, or they can perform the morph operation directly in the current Scenario. Engineers can also change one or many Control Valves at once, depending on the level of modification they want to apply.

This gives engineers flexibility in how they update or compare model configurations.

Where Engineers Might Use It

Because Control Valve junctions are commonly used as a design tool for sizing passive flow devices, there are many situations where the Control Valve Sizing Tool can help engineers move from design to finalized components. For example:

• System balancing after design
  An engineer may start by using Control Valves throughout a network to establish the desired flow distribution. Once flows and pressure drops are acceptable and Output exists, they can convert those Control Valves to Orifices or Valves in one operation using the calculated orifice diameters, Cv values, or K factors.
  
  
• Evaluating alternative hardware choices
  An engineer may want to see how a system behaves if certain Control Valves are replaced with passive devices. By morphing selected Control Valves to Orifices or Valves in a Child Scenario, they can compare system behavior between the design case and a case using equivalent passive devices—without manually recreating junctions or re-entering loss data.

Whether used in Fathom 14 or Arrow 11, the Control Valve Sizing Tool provides an efficient way to convert Control Valves while preserving key performance characteristics. Engineers can replace design-stage valves with equivalent passive devices confidently and without manual recalculation.