What size plumbing?

[sphelps]

The bigger the better for both lines, more flow and will allow for future upgrades. If you got the ability to run 1.5" for both, go for it.

[Myka]

The return size depends on the pump, you should find a reccommended size for your particular pump in the user manual. Many manufacturers recommend a pipe size twice the diameter of the in/outputs on the pump. For drains I would use 1". Are you doing Herbie drains?

[mark]

A single 1" drain is good for ~600gph and a 1.5" for around 1200gph (remembering if planning a Herbie, the second drain is normally dry and only flows in the emergency situation).

If doing a Herbie, me, I'd go 1" return and considering it's a 45g, probably just 2x1" drains if not planning on your return pump contributing significantly to the displays flow. 2x1.5" if you don't mind a bit of flow through your sump.

[Parker]

Quick question, do herbies flow faster then typical drains due to them operating at full syphon?

Does the 600 / 1200 gph hold true?

[Myka]

Quick answers: No to the first, and yes to the second.

Just because it's Herbie doesn't mean it can mysteriously take more flow. the only way it would is if it was overflowing into the emergency drain which totally defeats the purpose of the Herbie.

[sphelps]

Well actually a Herbie can drain more flow without using the back-up, provided it's done properly. For example if you have a standard Durso and you cover the air hole on the top you'll start a siphon and you'll be able to take more flow, this is especially a Herbie but you fine tune the flow rate with a gate valve to match the return and run a back up drain encase of the perfectly matched flow becomes unmatched. It's not a mystery but rather the effect of head pressure, so ideally the drains are placed at the bottom of the overflow and no extension tubes are used, this will however result in the entire overflow box draining during a power outage.

You can get around the overflow draining issue and you can also use a standard standpipe instead of a straight tube for back up. This will allow you to put a little flow through the back-up resulting a less finicky system and almost as quiet.

This is a system I commonly employed when I did installs, however it's better to have the two drains enter the sump separately rather than joining together first as shown.

[Myka]

It kind of can, but not really. A 1" pipe takes 600 gph no matter which way you try to shove water down it. It's just that which a Herbie you don't have a bunch of air taking up room in the pipe.

[Parker]

My thoughts behind the question:

Traditional overflows have air introduced into them to quiet them down. The overflow works on a weir type principle ( might be the wrong term ) Water flows over the edge of the pipe (HGB) and up through the pipe ( Duroso ) Since air is introduced into the system you have air mixed with water traveling down the pipe. With a herbie no air is introduced into the pipe, therefore space previously occupied by air is now being taken up by water. On top of that you are also introducing head pressure, how much of a difference that makes is up in the air.

[Parker]

Opps I was too late with my thoughts...