Farm question - SIPHONING a pond

[sbiel]

I've got a 3/4 acre pond that I am in the process of draining. It's about 10 feet deep at the deepest point.



I am going to be installing a siphon line about 2 feet above the lowest point, so this will not be strictly a drain, however it will prime on it's own. The outlet is well below the botton of the pond, so keeping a vacuum should not be an issue.



My question is this - for the drain lines, I am thinking about either three 2 inch lines or one 4 inch line. The speed to drain the pond is not real important. What I am not sure of is will a 2 inch line hold a better vacuum than the 4 inch line ??? At the bottom of the drain, I have a 90 degree bend (pointing upwards) to hold the water with a seal (to prevent vacuum loss).



My goal is to be able to open the drain valve(s) and have the water start flowing, quitting on when the water level drops below the inlet (assuming nothing clogs the line).



Thanks in advance for the help !!!

 

['956Wheel]

The larger pipe will have more vacuum and, if sealed 100% at all joints will not lose siphon and will start faster than the smaller pipe.



The entire piped section of th L. A. aqueduct is siphoned 300 or so miles... no pumps! from Bishop to L. A.



Mike

 

[illflem]

4" will be less prone to clogging

 

[sbiel]

Another question or two ...



Should I use (assuming I use 4" pipe) 4" pipe all the way down or at some point should I use a reducer to take it down to 2 or 3 inches ??



My thoughts were to go with 4" pipe, but I am open to other's ideas.



Yes, the 4 inch pipe is less prone to blockage - a very valid point. And my lines will be 100% sealed, so that should not be an issue.



Another question is this - will the larger pipe hold a vacuum ?? It would seem to me that the larger the pipe, the more the water that has to flow thru the pipe to keep the vacuum up ...

 

['956Wheel]

Leave it at 4". If you reduce it thats where it WILL clog.



Mike



Edit, On vacuum...

if you got a bigger pipe the weight of the water is greater thus the vacuum is greater.

 

[Doc Tinker]

Years ago, my boss showed me an old cast iron device that he claimed was used to aid in siphoning. It had a large iron bulb, that was evidently hollow, on top and the inlet and outlet hoses fitted to the bottom. The thing supposedly amplified the flow of water without being powered by motor or engine. Anyone seen something like that in action?



Doc

 

[illflem]

Doc is this what you're thinking of? They are way cool, but are a pump that doesn't use power. I've seen these made with $10 worth of pipe fittings. They will pump up 1000 feet, make a neat rhythmatic clanging sound.

http://members.tripod.com/ATLASPUB/index.htm Picture won't link look far right



sbeil, elaborate a bit further, is your pipe going up and over the pond berm or straight though?