There are some cases where the user needs to hide pipe supports in generated isometrics according to their requirement or work standard. To be able to perform this method, it is recommended to use or modify overrides.txt file which allows to set a rule to achieve appropriate outcome.
If above problem still persist, then please create a Service Request and contact the Bentley Product Advantage group. Please include a list of all relevant details to get in depth analysis for a solution or workaround.
http://communities.bentley.com/products/plant/design___engineering/w/plant_design_and_engineering__wiki/12641.modifying-the-iso-content
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