Elbows on drainpipes, what do they do?

[Mandelstam]

OK, a noob question... A lot of times you see elbows on drainpipes. What exactly are they for?

The Beananimal for instance has elbows and T's and caps on every pipe. Then I see Bill Wann in his Macna talk show his overflow that he's been using for the last 20 years (also three drains and works by the same principle) but without any elbows, just straight open (but with strainer) pipes.

So what exactly are the elbows for and are they worth the extra space/effort?

 

[mcarroll]

Overwrought is usually the word I think of when I think of the overflow you're looking at. It's a nice exercise in thinking and plumbing projects are always fun, but not practically of much use. If other drain styles were actually prone to failure, then it would be different story.....but they are not. I've used nothing but plain-jane U-tube overflows since the 1990's and never had a failure. The closest to it that I've experienced would be when I bought new overflows for my current system (~10 years ago) and one of them had a cracked U-tube. That one failed every time.

 

[Mandelstam]

I mean I like the idea behind the three drainpipes, the low noise, redundancy, etc, I'm just wondering about all the extra bells and whistles that Beananimal put on there...

 

[mcarroll]

Listen to your gut.....it's wondering in the correct direction.

Any gravity drain is almost totally silent with the correct amount of water running through it. Threads where you see noise complaints are often "more is better" situations where folks have just added the biggest pump possible and are trying to max everything out. Not a good strategy in the first place....especially if silence and simplicity are goals.

2x-4x return flow is fine range to target...and is a flow that any standard single drain will handle silently.

For more flow than that (not needed in most cases) you may need to increase the drain size or number of drains for the system to remain silent.