Adjustable Y-fitting

Here is an example of a Y-shaped adapter generated on iteration3d:

https://www.iteration3d.fr/en/templates/template-view.php?templateid=2

You can easily generate another one tailored to your needs — not only 3-way, but also 4-way up to 10-way splitters.

Set the number of branches, inner and outer diameters, and optional end fillets.
Click Generate — it’s done.