When you place pipes underwater and are above the water, the pipes often don't render at all. There seem to be chunk borders involved somehow.

In the below image, there are pipes basically in a straight line there going into the hole in the side of the wall

I am unable to reproduce this effect. Please provide testing steps and what mods you have loaded.

Oh, it might be a sodium bug then. I'll see if I can reproduce it tomorrow, with and without sodium

Were you able to reproduce it without sodium?