P-trap angle question

I'm installing a new drain for my shower, and I'm having some trouble working the drain pipe around some joists to the horizontal pipe leading to the main waste line. I have 2 questions.

#1 how far can the outlet portion of a p trap be rotated? See image below #1 is the nomal installation I see and I have seen some done as in #2. My tight situation would require #3, almost doubling back. Would this be a problem?

#2 after leaving the outlet of the P-trap the waste pipe will connect with a horizontal drain pipe that leads to the main house 3" drain. The issue is when running a drain horizontally, I know you must have 1/4" of drop per foot. Is there any limitation on the severity of the bends over the course of the horizontal line. In my situation a 90 bend would "work" but would this severe turn slow down the drain? Would 2-45s be a better solution?

thanks in advance

plumbiong

I am no plumber but...

1. The trap is made to point in any direction and I can't see a reason why the flow would be reduced by doing so.

2. The IDEAL situation would always run a sweeping turn but I know from experience that they do tend to take up a lot of space so you could use a 3x3x2 sanitary T (some codes won't allow it though). The only thing you need to really avoid is using a vent 90, way too shallow of a turn. I used nothing but 3X3X2 sweeps in my system and one 3X3X2 45 degree with a 45 adapter.

top view, then OK

assuming that i have seen top views, looking down, then you are fine. You can turn it like it shows. and it is not a problem.

the other question appears to be whether two 45 degree bends are better than a 90, and the answer is always yes, and never no. But it isn't usually critical, and no-one is going to insist, and someone might even say it makes no difference in 99.9% of applications. But the answer is still yes, and always yes, at all times, everywhere in the world.

When connecting a horizontal drain pipe (with small slope) to a bigger drain on the same plane, use a "Y", a Wye. Otherwise you have to let the water fall in from above, and then you have a few options.

i hope i understood your situation and gave you answers that helped. i read the above response and i'm not sure i caught it all, about T's.

david