Ok before we get started here, I do know the idea behind a herbie. However I consistently see the outflow being submerged in ones sump. My question is MUST it be submerged to create the full siphon if that gate valve is right at the end of the pipe. Would the pressure of the water flowing continue the full siphon or is there a chance of the air seeping back up into the pipe and making this all pointless? Or do people keep it below the water level for noise reduction?
Herbie overflow output question
- Thread starter savannah_az
- Start date
I have seen it displayed in 3 ways:
1) free discharge
2) open discharge (just above the water)
3) submerged discharge
My impression is that the preferred choice is (3), although there are other reasons one might be using the other 2 methods.
All produce the same siphon amount (according to calculators) provided they are designed properly to restrict air intake. That might be true because the distances being covered are relatively small (2-6 feet), although I don't know the mechanics to explain how (1) woks the same as (2) and (3.) It makes sense that the noisiest is (1), the next being (2), and the quietest (3.)
Valves are useful to control the down flow in (2) and (3) in cases where it's excessive. Recall that up to a point, the siphon increases the farther the liquid falls in a straight line. People who have very steep drops (e.g., to a basement) might have a desire to restrict the siphon.
1) free discharge
2) open discharge (just above the water)
3) submerged discharge
My impression is that the preferred choice is (3), although there are other reasons one might be using the other 2 methods.
All produce the same siphon amount (according to calculators) provided they are designed properly to restrict air intake. That might be true because the distances being covered are relatively small (2-6 feet), although I don't know the mechanics to explain how (1) woks the same as (2) and (3.) It makes sense that the noisiest is (1), the next being (2), and the quietest (3.)
Valves are useful to control the down flow in (2) and (3) in cases where it's excessive. Recall that up to a point, the siphon increases the farther the liquid falls in a straight line. People who have very steep drops (e.g., to a basement) might have a desire to restrict the siphon.
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So in theory, the velocity of the water on any drop would ideally be enough to keep air out of the siphon from the "exhaust" end assuming its already running at full capacity. Is anybody running it like this that can vouch first hand?
The siphon won't be affected above the valve that is used in the line to restrict flow and create the siphon. However, the line between the valve and the sump could fill with some air, depending on how much flow and how large the line is. The reason people run it submerged in the sump (I do have mine setup this way) is because it doesn't allow any air to enter the line at all, and creates a completely silent drain that is capable of very high flow. If the line is not submerged in the sump then you will have a lot more noise. Think of it like when you are filling a tub or bucket with a hose. It may be quieter than a non-siphon drain but it will be much louder than a submerged siphon.
I don't have a sump per say so I have no way to submerge the overflow pipe. So I'll try this out and update the thread with of its quoted than just running it with stand pipes in case anyone else ever needs this info. Thanks you two.
I submerge the output on mine because it's quieter. But, also, because it's a constant back pressure, and that helps the gate/siphon/system run more consistently. I have a drip system with an upturned elbow, maintaining a constant water level in my sump. With the drains being under that level, it's just all a more constant drain rate--so little or no adjustment to the gate valve.