A little help with ABS fittings

I recently bought a travel trailer to live in when I'm working since my work is fairly transient. It was -35C the night I hooked up to it after I bought it and on the way out I clipped a piece of wood and it broke all three of my drainage pipes off. Two of them I'm certain I can fix at the tank, but I do have to replace my black water tank. The campground I'm at luckily has a nice showerhouse so I'm not in a huge hurry to get this done, although trucking my dishes over there is becoming a pain.

I also only have Sundays off and there are not RV parts places open on Sundays in my city so I'm reserved to purchasing online.

I'm having some trouble figuring out a couple parts. I've been using this online catalog. http://www.rvretailcatalog.com/ But there's a few things I can't seem to find or I'm not sure I'm choosing the correct part.

1. Are the smaller DWV valves that the 1 1/2" pipe goes into 1 1/2" or 2"? Seems like a stupid question, but the only wye collector I could find was a 3" bayonet end x 3" stationary flange x 2" slip hub leading me to believe that the small waste valve must be a 2" and on the 1 1/2" pipe side of the waste valve that it is an 1 1/2" female slip hub with 2" flange attachment? I am super new to all of this so please bare with me.

2. My next question is on 3" 90 degree hub fitting. How is it connected? Does it have a male on both sides coupling that slides into the elbow hubs? It looks like there is four of these used from where the 3" DWV valve starts to up to the top 90 degree elbow.

3. I also couldn't find a Bend collector like the one you see in the last picture. I believe I need a 3" slip hub x 3" slip hub x 2" slip hub. But the only ones I can find are 3" slip hub x 3" rotating flange x 2" slip hub.

Any help is greatly appreciated.

Cheers.

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