Hi,
you can replace the pipe connectors in InfraWorks with any 3D model of you joice. Simply select the 3D model and adjust the style settings.
The structure in your example is not in the default style catalog. You either need to export it as 3D solid and create a new style for it in InfraWorks or you can search for decent 3D models that are available for free in the internet. A good staring point for example is the sketchup 3D Warehouse (https://3dwarehouse.sketchup.com/).
See also this link for how to import sketchup models in InfraWorks:
http://beingcivil.typepad.com/my_weblog/2013/03/autodesk-infrastructure-modeler-importing-skp-model-...
Regards,
Karsten.