Help me identify my rough in plumbing pipes
If the basement bathroom requires a sewage pump, one of those pipes (quite possibly #3) will be the output of the sewage pump going up to the level of the house drain (which is presumably above the floor level, if a sewage pump pit was roughed in.) Pull the cover off the pit and poke a snake into the pipes...
Or if there's only one pipe into the pit, and the pump output would go out via the cover, it may be a vent pipe and cleanout access.
Lack of vent pipes above the concrete is fairly normal. The rough in is &quot;put pipes before pouring concrete&quot; rather than &quot;prepare all for a bathroom that hasn't been put in for the next 11 years, and may never be&quot; - pipes above the concrete are easier to add than those below.
Sump basins are pretty generic - make sure the pump you want to buy fits in the one you have, but that's pretty much physical size of pump and hole, not brand-specific. The part number is for exactly what it is - a sump cover. There will be a sump basin under it, with the plumbing run to it if it's in fact for a sewage pump. An alternate possibility (not knowing where your sewage or septic pipe leaves your house) is that the sump cover is covering &quot;the other kind of sump&quot; (drainage) and the bathroom plumbing goes directly to your septic or sewer pipe below floor level. Once again suggesting open it, take a look, poke a snake in the pipes and see where it comes out, or listen for it, anyway.