Inverted siphon

Inverted siphons are not always the same in CAD. The drawing should reflect the installations, the head diferential required across the siphon, the depth of any structures it must pass under, the separation depth of the siphon under such structures. Essentially it is just a pipe that follows a curve (and sometimes a straight portion) under some physical structure to convey gravity flows like sewage, from the siphon entry to siphon exit. Sometimes these will have casings outside the conductor pipes, sometimes (frequently) they will have multiple conductors inside the casing. The radius and legths are frequently driven by the method of installation. Installation processes like HDD have minimum and maximum diameter, pull stresses, pull lengths, curvature and slope requirements for the equipment, materials and soils specific to the project. All of these need to be engineered.

".. and am having hard time to find more detailed picture so I can draw it"

An Inverted Syphon, Down Page

Large Scale Inverted Syphon

Hello Guest

Larger inverted siphons are often used to get an irrigation canal towards and under a flowing river, to the other side, and up to the surface, where the irrigation canal keeps flowing away from that river.

In essence an inverted siphon is shaped like the letter U with a flat bottom instead of curved as per the bottom of the letter U.

The water flows into one arm, and flows out the other.

We do have several of these, all made of concrete, some under quite large rivers, within 70 miles of my location.

Have a look at some diagrams and calculations here:

http://www.lmnoeng.com/Channels/InvertedSiphon.htm

Don't forget the feedback here please ....

Hi Sparks... Meaning your link was/is better that what I posted. By activating the calculation features you have a ready made design tool for large scale Inverted Syphons!

wiki says this.

that could then be transposed to all other uses.

Have fun.

Lady Beware! Anyone can draw a siphon! It's the dimensions that count. There are two HEADS involved in the design of said device. I think a good Hydrolgy or Civil Eng book can show you in detail all calculations and dimensions involved. Sorry I'm not CIVIL.

From the wiki article and general piping and transport considerations, I guess I dont see anything particularly unique about designing an "inverted siphon" except for consideration that flows must be great enough to preclude salting out of any particulate matter that would interfer with flow.

If you are designing your inverted siphon for sewage and the like, with high levels of particulates, it is important to have multiple small pipes rather than a single one.

That way the current speed remains faster in each pipe, preventing sedimentation at direction changes in the siphon, with the eventual blockage, and clearing trouble.....

Why don't you try puchasing a 2inch piece of sched 20 pvc pipe, bend and form an inverted siphon to your liking, cut to length as you desire, draw your design on a paper, add all lengths, dimensions and properties with total disregard for engineering design specifications and try to sell it as a bonafide 100% engineered device that will work all the time?

I think that is exactly what should happen indeed, it is only a kind of syphon for pete's sake. If it does not work so what, you go back to your shed and try another shape. No child overboard.

Most of these inverted syphons are only to stop the stench coming back into the house and we all know they do not always work either, even if you buy a so called "bonafide" article.

Anyway, who are you calling "lady"? You show a funny local hairdo yourself or are you posing in front of mount krakatoa

Only kidding of course, you all know me by now

Lady, is for the Guest; I think it's a woman...and the Doo is a ball cap I put on backwards. The backgound scenery is from somewhere you should go some time, like I do twice every year. It's the Grand Turks and Caicos Islands. Jimmy Buffets famous island spot and home of Margaritaville. Take a vacation, maybe cool-off a bit...?

That just shows we all have different interpretations of what we look like. I never thought the poster was a woman, I thought it was a school kid maybe doing some thesis or homework.

Hey Ronald, I just fooling around man, that's why I state that fact just to make sure for everyone.

It is early evening here, slowly winding down, I don't tend to take things too seriously this time of the weekend unless I really have to.

Vacation, I take one of those to warm up, not to cool down. I live in England remember.

An inverted syphon is a 'U-bend'. Nearly every flush toilet pan has one.

What can I say, except a picture is worth a thousand words: ...

The drawing is simply a pipe, sometimes with pipes inside this outer casing, that is the simple part as someone noted above. The drawing has to properly reflect the design though. An inverted siphon design is easy, just need to calculate the head losses to the pipe during flow at minimum flushing velocity (typically 3 or 4 fps) for the conductor pipe size and material over the length of the proposed arc it will follow (this may need to be reiterative to achieve proper locations and depths for inlets and outlets). The arc it follows, flat linear section lenghts and locations, and the entry and exit angles are dependant upon the limitations of the method of installation (e.g. HDD) and strengths of the materials chosen. Materials stresses and fracture potentials are dependant on the stratigraphy you must pass through, so you should have a geotechnical investigation conducted to at least 5'10 feet below the bottom of your installation. Also there are maximum exit angles to properly flush the siphon that should not be exceeded. Typically local authority (municipal or county public works) will set the standards you must meet. You can set up a interative process to evaluate the path, relative to pipe size and materials and entry/exit points. The outer casings will typically be steel, though sometimes HDPE can be specified (small diamter and very thick). Typical limitations that must be considered in the use of these structures are adequate depth below the bottom of the structure you must pass under, typically at least 25 feet clearance, flushing velocities at exit, maximum exit angles for flushing, minimum and maximum entry/exit angles for installation, maximum curvature, maximum material stresses, soils strenghts and friction, etc..

Dear Sir,

Did you receive a reply to your need for an AUTOCAD drawing of an inverted siphon? If so, could you please send me the AUTOCAD drawing of an Inverted Siphon? I currently only have AUTOCAD 2000. So could you please send it to me in AUTOCAD 2000 format? My e-mail address is: johnjgamel@hotmail.com.

Thank you in advance for sending.

John Gamel, EIT

Engineer

Ezra Golub Assocaites

4141 Woerner Avenue

Levittown, PA 19057

Telephone: 215-943-2230

FAX: 215-943-7944

You guys do realize the drawings are just a set of conductor pipes set within a casing pipe. I would suspect you probably should not mess with inverted siphons if you are having trouble with the drawings, as this is the simple part. If you just need an example, any large modern City's Public Works will have typical siphons shown in their Standard Drawings. Try looking it up in like LA's standards or NYC's for examples. However, every siphon differs to fit the design needs. Casing is sized to fit the conductor pipe that must pass through within materials limits and cost (plus some additional for pulling the conductor pipes). Also, I noticed in original post qurestion about pipe fittings. It is probably best not to mess with a inverted siphon if you do not already have some knowledge of how the pipe segments are connected, you should probably have some experience already with major conductor pipelines before getting into siphons.

did any mention the venturi effect