Resolving Common Issues

If you encounter issues placing hangers or supports using the MEP Hangers solution, this article addresses common mistakes that prevent successful insertion.

Report Window

When a configuration fails, the software typically generates a report window indicating the MEP elements where hangers couldn't be inserted.

You can select a row in the report and click Show Element to highlight the element in the view for examination. If the configuration fails for only a few selected MEP elements, you can click OK to proceed where possible or Cancel to undo the whole operation.

The report window also provides the Configuration Name and the Rule Name associated with the failure.

Some configurations can have multiple rules and this is what the Rule Name column refers to.

If you encounter an error message and are unsure how to resolve it, or if no hangers are being inserted without any error message, follow the steps below:

1. Hangers are placed but not visible in the floor plan

This is a common issue. If you run a configuration in a floor plan and no hangers appear in the view or and no error message is displayed, it’s likely that hangers were inserted but simply aren't visible in the view.

Solution:

• Switch to a 3D view to check for hangers. If they are present, adjust the cut plane's height in the floor plan to ensure their visibility. Keep in mind that this adjustment may impact the visibility of other elements.

• Alternatively, use the Mechanical Equipment library for hangers. Hangers in this category are visible in floor plans even when above the cut plane, unlike those in the Structural Connections category. Before doing so, refer to this article on the differences between StrC and MeEq category hangers, and the guide on setting up MeEq hangers.

2. Structural elements aren't found

Another frequent error occurs when the structural elements, specified in the configuration, aren’t located within the project. These structural components serve as attachment points for the hangers (such as floors, roofs, walls, and other supports in the case of multi-level hangers). Without these elements, the software cannot calculate the lengths of rods (or other vertical structural members) or determine where hangers should be positioned.

Let's consider a straightforward example: You're attempting to place hangers for a run of pipes beneath a floor. These pipes are 802mm away from the floor, measured from the top of the pipe:

Suppose the Structure Selection in your configuration looks like this:

Running such a configuration would lead to an error. The section highlighted in blue indicates the categories the software searches for to attach hangers.

You should check the category of structural elements above the pipes. If it’s a linked file, you can still select the element by hovering the cursor over it and clicking Tab until it's highlighted (ensure that Select Links and/or Select Pinned Elements are enabled).

Solution:

If the category differs from what you have in the configuration (blue section), tick the respective checkbox in the configuration. You can also select multiple categories if necessary. If the category is not listed, there's a workaround at the bottom of this article.

It could also be the Searching Rule Name (green). This rule determines the direction in which the software searches for structural elements. For instance, 'Bottom' indicates that it's searching below the pipes.

Solution:

In this example, you should set it to 'Top' because the floor is above the pipes.

The 'Searching Distance' determines how far the software will search for structural elements.

Solution:

To locate the floor in this example, let’s increase the value. It needs to be at least 803 mm. To avoid frequent configuration adjustments, let’s set it to a safe value of 1000mm.

If your Project Units are imperial, the configuration will also use imperial units.

Settings highlighted in grey are additional filters you can set. If the filter criteria aren’t met, this can also result in an error. Be sure to review these filters as well.

After modifying these settings, the configuration will be successful.

Please note that this example represents a worst-case scenario, and most of the issues can be avoided by selecting an appropriate configuration from the start.

Additionally, some settings can affect the runtime of a configuration. Therefore, it's not recommended to select all available categories or set an extremely large max Searching Distance value. You can find more information about the individual settings in this article.

3. Filtering MEP elements

In the configuration, you can also establish filters for MEP elements. You can use any property of the MEP element to filter by.

For instance, in this example, I’m filtering only the pipes larger than 200mm in diameter. However, since the pipes are smaller, running this configuration wouldn’t place any hangers. A report window wouldn’t appear either, as the configuration precisely executes its intended function – placing hangers only if the diameter exceeds 200mm.

Solution: Simply modify or remove the filters.

Note that these filters are often used with Rules to place different hangers or adjust spacing based on the properties of the MEP element. Some rules are intentionally designed to "fail." Be cautious not to delete filters that were created for specific tasks.

4. Spacing

In rare cases, the Spacing options can trigger an error, particularly for Layout Direction/Layout Rule sets that include 'Start Offset' or 'End Offset' options. For example, if a pipe is 100mm in length and the Start Offset is set to 200mm, the software will attempt to place a hanger 200mm from the start of the pipe, resulting in an error.

Solution:

Adjust the 'Start Offset' or 'End Offset 'value or consider using a different Layout Direction and Layout Rule.

To prevent this issue in the future, it's advisable to create a Rule specifically for short elements. In the provided example, the configuration includes 2 Rules: one for short pipes, which places a hanger in the middle of the pipe, and another for other pipes, which follows typical spacing settings.

5. Other issues (and a workaround)

If none of the points mentioned earlier improved your situation, the error could be caused by other combinations of settings. You can read more about configuration settings in depth in this article.

It can also be caused by unrecognized objects in the Revit model. However, there's a workaround that can address most other potential issues.

Solution:

Create some 'placeholder'/'dummy' structural elements in the active MEP model.

For instance, if the software isn’t detecting a floor above (and you’ve addressed all the points in #2), create a Floor element and align it with the architectural/structural floors from the linked files. Then, set the 'Search in Project' option to 'Current Project' only. This ensures that the software will only locate the 'placeholder' Floor, to which a hanger can be attached.

Afterwards, you can easily hide these 'placeholder' elements from your floor plans or 3D views using Visibility/Graphic Overrides.

This method is also applicable when linking IFC structural/architectural files, which may have unusual categories assigned. For example, the floors or walls might be classified as Generic Models. While it’s also possible to address this through 'Import IFC Options' in Revit, the 'placeholder' solution may sometimes be quicker.

Conclusion

Following these steps should allow you to insert hangers/supports into your Revit model. If the problem persists, contact us at [e-mail].