I was thinking of placing the pipe angled over, turning 45 degrees and then crossing the beam and then up, but the question is more about whether it will bear enough if I drill diagonally? I'm going to lay tiles over it afterward, so it needs to be stable 
Do you mean that you want to drill diagonally into the beam? I think that's unnecessary unless you really have to. Otherwise, mlkjlrhr is on the right track. In the middle of the beam and as close to a support as possible gives the least impact.
If you drill an 80 mm hole in the center, the beam weakens by ~16%. Whether the hole is round or oval (angled) doesn't matter. From a strength perspective, an oval hole is better (fewer stress concentrations).
To "cure" the weakening, you can glue 4 strips on the sides / above / below. H=45 mm B=20 mm makes the strength around the hole about 20% higher than original. Then you can make your hole however you like between these strips.
To "cure" the weakening, you can glue 4 strips on the sides / above / below. H=45 mm B=20 mm makes the strength around the hole about 20% higher than original. Then you can make your hole however you like between these strips.
Thanks for your answers,
If I go through, I am now considering taking two 45-degree bends and going straight through the beam, then two 45-degree bends upwards.
If you look at the picture, it is built from the basement (is it called a "hjärtvägg"?) approximately in the lower left corner of the picture (where the prism goes), where the beam is spliced and rests on, and the drainage should go up where it says "disk" if it makes any difference in load-bearing?
Pno, your alternative is not a bad idea either.
If I go through, I am now considering taking two 45-degree bends and going straight through the beam, then two 45-degree bends upwards.
If you look at the picture, it is built from the basement (is it called a "hjärtvägg"?) approximately in the lower left corner of the picture (where the prism goes), where the beam is spliced and rests on, and the drainage should go up where it says "disk" if it makes any difference in load-bearing?
Pno, your alternative is not a bad idea either.
Had a similar issue some time ago, however it was 110 pipes and a thinner beam. I ordered a flat iron approximately 170mm high and about 800mm long, with holes at 120mm and several holes for screws.
Screw-glued it there and sawed the hole.
Screw-glued it there and sawed the hole.
Reinforced my 3 pieces 220x45 with 22mm plywood on each side-
