Roman Aqueduct w/Siphon lock?

109A_5

RickDelta said:

I still have no clue as to what the "siphon only flow" gpm would be.

When I shut off the pumps and noticed the water was still discharging long after, then putting my ear up to the pipe and touching it, I could tell a very large, solid volume of water was flowing thru this pipe!

Well it is more than no flow and less than the pump, maybe there is an engineering web site with some formulas for siphon flow characteristics. Presently I bet the pump is a restriction in siphon mode.

Curious does the flow continue if the discharge end of the pipe is above the canal water level ?

If you get it set up and controlled properly for the most efficient use of a siphon you probably could reduce your electric bill a bit.

109A_5

Maybe this will help.
https://www.engineersedge.com/fluid_flow/siphon_flow_rate_15114.htm
https://www.engineersedge.com/fluid_flow/siphon_flow_and_discharge_rates_15113.htm

RickDelta

Question:
Wouldn't the addition of a "foot check" valve aid or emulate immediate water flow close to the start up performance of the submersibles?
(not having to wait for suction pipe to prime)

109A_5

RickDelta said:

My actual service gpm is around 230 gpm with head loss.

You have two 4" pipes, right ? Looking at the charts, if you get the siphon working correctly, you may only need to run a pump (water or vacuum) a few times a year and only have standing water in the sump pit.

RickDelta

"@109A_5"
Curious does the flow continue if the discharge end of the pipe is above the canal water level ?

No clue! : ( ....... its surrounded by very tall grasses and cattails.

109A_5

The foot check valve may help the pump maintain a prime (as long as it does not leak down) but may cause a restriction in the siphon path. Unless the siphon uses a separate dip tube with its own swing check valve. Swing check valves require very little cracking pressure, but have to be orientated correctly.

109A_5

RickDelta

"@109A_5"
If the single siphon can't keep up with with the water ingress to the basement the second siphon could be activated then if needed

My thinking was always to use both 4" PVC discharge pipes for max. GPM siphon flow. (hoping this acquired siphon flow would equate to 70% of my basement ingress during the year)

109A_5

RickDelta said:

Thinking:
If water level again rises, release stop solenoid valve to resume siphon flow (no pumps).

Why even use a solenoid valve in the discharge pipe?

The problem I see with this is, during the inactivity time if the long primarily horizontal discharge pipe drains and air get in and the vacuum is not maintained you no longer have a siphon and you would have to re-prime the system.

109A_5

RickDelta said:

"@109A_5"
If the single siphon can't keep up with with the water ingress to the basement the second siphon could be activated then if needed

My thinking was always to use both 4" PVC discharge pipes for max. GPM siphon flow. (hoping this acquired siphon flow would equate to 70% of my basement ingress during the year)

I think done properly it can recover the lowest basement tier and keep the water in the sump pit except the water that may run across the floor.

Looking at the graphs, if your actual (pumped) service GPM is around 230 GPM max I would think the siphon would cover 99% with the 1% for priming with a good working system. But I am not there and have not lived with the issue.

If your two 4" pipe systems are basically independent I would use them that way (except for maybe the PLC). Let the PLC determine the evacuation rate needed (water rate of rise) and save the electricity of the extra valve control, pump priming, etc. If you can maintain a siphon prime, throttle the system as needed. I think I would try to find a power to open and power to close type valve so you are not powering the valve (or solenoid) continuously for a significant amount of time.

Also using only one 4" pipe when needed it may reduce the open / close cycles and thus wear and tear. The PLC can flip between the two systems and detect failures if you get creative.

I think I would monitor the sump pit at 20% height and 90 % height. 90% starts minimal evacuation and should reach the 20% in a given time (TBD). The 20% shuts down the process so the prime is not lost to air getting into the intake pipes. If the greater than 90% remains for a extended time the second siphon is activated. If the 90% still remains for an additional time period a pump is activated, and so on...

RickDelta

"@109A_5"

Looking at the graphs, if your actual (pumped) service GPM is around 230 GPM max I would think the siphon would cover 99% with the 1% for priming with a good working system.

 ....... that's 230 + 230 + 115 = 475 gpm at max. ingress.

(2.5 pumps !)

RickDelta

Another foot note:

Even flooding the bottom tier as I want, I'll have to stop pumping when I get to the basement floor level, leaving the existing small sump basin full to the top.

With four 3" PVC vertical suction pipes residing almost all the way down inside this small basin, the suction inlets would draw air in even under water via a generated spiraling vortex if there is not enough water above them.

109A_5

If you reduce the flow slowly and have enough water over the end of the pipe, I bet it won't be an issue.

Maybe a simple and inexpensive way so air can't get back into the discharge end.

leonz

My work with 2 plus decades work with mining equipment involved dealing with vacuum(pressure gradient) rock dust collection systems and large diameter suction(pressure gradient) and pressure(pressure gradient) piping for hydraulic systems.

Induced vacuums with fluids occur with full flow saturation in suction lines to main pumps and the vacuum is broken by removing the plug at the top of the elbow weldment when a primary or secondary oil pump needs to be replaced explained by the continued rush of water out of the piping in the basement and to the canal and the basement sump.

When the vacuum(pressure gradient) is broken the oil flows back into the oil reservoir eliminating a massive leak.

The vacuum/syphon (pressure gradient) is lost once the water volume has ceased to fully occupy a pipes circular diameter and the remaining hydraulic oil or water as a fluid flows back to a reservoir or out of a blown hose or pump seal.

Atmospheric air or compressed air is also a fluid and must be treated and controlled as a fluid which makes dry and wet steam systems work so well in their operation.

This also works when multiple suction hoses and pressure hoses are connected at a machined block used to connect the pressure and suction hoses above the oil level in cramped compartments where the torque converter and the gear pumps are located which makes it easier to remove the bad steering or main pumps with little fluid loss and mess.

Jamie Hall

In terms of calculating the flow in the pipe, as I said above use the Hazen-Williams formula. The slope to use is the difference in elevation between the water level in the inlet pool and the water level in the canal -- the fact that the pipe goes up and down is irrelevant -- divided by the length of the pipe plus an appropriate allowance for fittings.

RickDelta

Jamie Hall said:

In terms of calculating the flow in the pipe, as I said above use the Hazen-Williams formula. The slope to use is the difference in elevation between the water level in the inlet pool and the water level in the canal -- the fact that the pipe goes up and down is irrelevant -- divided by the length of the pipe plus an appropriate allowance for fittings.

........ my head starts to spin looking at that formula! : (
Not sure of what references their referring to.

I'm going to install the magnetic field flow meters and then I'll get my answer from them.

leonz

In using my Desk Reference handbook: 4th Edition 7th printing January 2021

Page 1102 in reference to 'Horizontal Pipe Discharge".

"Gallons per Minute Discharge for a given nominal pipe diameter"

Line one on page 1102 refers to 4 inch pipe as having flow volume of 83 gallons per minute with a 4 inch drop of the flow volume below horizontal in L(length) distance which is 4,980 gallons per hour; 119,520 gallons per day; 836,640 gallons per week.

RickDelta

leonz said:

In using my Desk Reference handbook: 4th Edition 7th printing January 2021

Page 1102 in reference to 'Horizontal Pipe Discharge".

"Gallons per Minute Discharge for a given nominal pipe diameter"

Line one on page 1102 refers to 4 inch pipe as having flow volume of 83 gallons per minute with a 4 inch drop of the flow volume below horizontal in L(length) distance which is 4,980 gallons per hour; 119,520 gallons per day; 836,640 gallons per week.

I'm at a 12ft water level differential to the canal ..... what's the expected siphon flow in gmp then??

leonz

As far as I know it is still 83 gallons per minute if the pipe is full, as you have one atmosphere of pressure at both ends of the syphon.

The syphon would break once the water weight above the syphon decreases.

Pumpguy

I didn't realize you already have this pump installed and piped.

The idea of the check valve in the bypass around the pump for syphon only operation is something I didn't think of. Nice touch.

With a pump started syphon arrangement, I really don't think you need a check valve at the outlet to the canal. (A vacuum pump primed syphon arrangement would need the check valve or submerged outlet water seal.)

So long as any opening to atmosphere is below the syphon inlet, the weight of the falling water column should keep the syphon operating.

RickDelta

RickDelta said:

leonz said:

In using my Desk Reference handbook: 4th Edition 7th printing January 2021

Page 1102 in reference to 'Horizontal Pipe Discharge".

"Gallons per Minute Discharge for a given nominal pipe diameter"

Line one on page 1102 refers to 4 inch pipe as having flow volume of 83 gallons per minute with a 4 inch drop of the flow volume below horizontal in L(length) distance which is 4,980 gallons per hour; 119,520 gallons per day; 836,640 gallons per week.

I'm at a 12ft water level differential to the canal ..... what's the expected siphon flow in gmp then??

I would think a 4" drop in elevation compared to and a 12ft drop in elevation there would be a large difference in siphon flow in gpm??

Jamie Hall

You're not taking into account the length...

RickDelta

Jamie Hall said:

You're not taking into account the length...

I do know in a "siphonic roof drain system" its the elevation that gives it its powerful siphon flow rate.

RickDelta

https://youtube.com/watch?v=_ELwOXIiwAI

RickDelta

https://www.youtube.com/watch?v=5O0EDaZV8XE

RickDelta

Siphonic water flow

Jamie Hall

RickDelta said:

Jamie Hall said:

You're not taking into account the length...

I do know in a "siphonic roof drain system" its the elevation that gives it its powerful siphon flow rate.

Indeed. But you still need to take into account the length of the pipe...

109A_5

The friction loss due to the length of the pipe may diminish this flow rate and the chart with the 4" pipe was in cubic feet per second. Even with a 3" pipe that's a lot of water.



If it were me, I set up the system to try to maintain the siphon prime, regulate the siphon flow rate to equal the water ingress to the basement at any given moment and only use the pumps if more flow is needed above and beyond the maximum siphon rate.

Let gravity do the work not the electric bill.

RickDelta

"@JamieHall"

If you were to guess (GPM Flow) ...... two 4" pipes under a siphon with my elevations and lengths?

RickDelta

109A_5 said:

The friction loss due to the length of the pipe may diminish this flow rate and the chart with the 4" pipe was in cubic feet per second. Even with a 3" pipe that's a lot of water.



If it were me, I set up the system to try to maintain the siphon prime, regulate the siphon flow rate to equal the water ingress to the basement at any given moment and only use the pumps if more flow is needed above and beyond the maximum siphon rate.

Let gravity do the work not the electric bill.

......... Agreed! : )

The main problem I'm up against is I have to install a completely new pumping station ........ while its under flash flooding conditions!
: (

If I turn off the power to the existing submersibles (to work safely in that water basin) ........ I have about 20 mins of work time then to get out of there as the water level is up to the bottom of the 3-phase power panel on tier two (aprox 4ft of water).

RickDelta

...... I'm getting ready to drop in some temp pumps so I can work down there.

That makes 7 pumps total running! (3 big guys and 4 small ones)

109A_5

Well I'd pump it down using one or both 4" pipes then if one 4" pipe and the submersible pumps will maintain it start to convert the other 4" pipe to a siphon configuration that is prime-able with a pump and with a pump siphon bypass. The first build-out may have to be versatile to determine what works and what does not.

You probably need to plan your attack in doable stages and it may be weather or season dependent.

Good Luck !!!

Jamie Hall

RickDelta said:

"@JamieHall"

If you were to guess (GPM Flow) ...... two 4" pipes under a siphon with my elevations and lengths?

Somewhere around 500 gpm for the two of them together, if both are unobstructed.

You still haven't mentioned a discharge permit to that canal. Clear water or not, you need one. You also need one into the storm drains, if you were to go that route.

And trust me. You really truly don't want to do this without the proper permits. The resulting fines and litigation, when the authorities catch up to you (which they will), will bankrupt you.

WMno57

During the recent major street intersection rebuilding project by the township, they allowed me to install two 4" PVC pipes thru an abandoned 3ft storm sewer pipe that crossed under that highway (see pic below) beside us.

This now gave us a direct discharge path to the canal.

Think: This new discharge piping became one "air tight" sealed tube from suction pipe starting point all the way out to the canal! With a water level differential approximately 8ft)

Do your two pvc pipes go all the way to the canal? Under the Wawa driveway?
https://www.google.com/maps/search/bristol+beer+store+bristol+pa/@40.1181705,-74.845914,337m/data=!3m1!1e3?entry=ttu
Why was the 3 foot storm sewer abandoned? Is it possible one or more of the new retention ponds have a failed liner and they are draining into your basement?
The storm sewer would make a nice adit to dewater your basement by gravity. No pumps or electricity needed.
https://en.wikipedia.org/wiki/Adit

RickDelta

"@WNno57"
Do your two pvc pipes go all the way to the canal? Under the Wawa driveway?

No .....they stop at the corner there. Thats a side tributary about 100ft short of the canal. (this tributary runs under WAWA driveway). I could easy extend to the canal if needed.
The state engineer didn't want us to discharge into their retention ponds because of their capacity design calculations.
But if we were to have discharged into these retention ponds, we would just be putting the same water we just pumped out back into our basement! : (

RickDelta

I've been saying "retention" pond, but what we have around us on three sides is really a "detention pond" ...... a "dry" pond.
It only stores the rain water for a short time then is slowly metered off to the canal. Most the time its just a dry basin.

RickDelta

"@WMno57"
Why was the 3 foot storm sewer abandoned?

No clue! ..... It was just a section of it that only extended the length of the width of the highway.

Foot note:
Our discharge ended at our property line at the corner. I don't think the state or our township ever addressed our existing 80 years of discharge to the corner in their new intersection redesign plans.
To address this, their "on-site" solution was to install two 4" PVC pipes for us over to the canal for discharge. We did our tie in at our property line only.

RickDelta

@JamieHall"

Somewhere around 500 gpm for the two of them together, if both are unobstructed.

........ that's a lot of water!
Our highest ingress water flow looks to be around 475 gpm.

RickDelta

109A_5 said:

Hello @RickDelta,
Maybe an Eco friendly receiver in the canal to raise the water level for the discharge pipe.

........ I'm going to go with your design here. Pure simplicity! : )

Here goes! : )

(these pics are directly over the 3ft round existing sump basin in the basement)





The door will be raised up 4" off the floor with a ledge to step over into pump room.
The entire room will be like a "panned" shower floor w/drain.

Paul Formisano

The short answer is yes.  The thing required for a siphon to flow is that the discharge end is lower than the intake end.  The discharge doesn’t have to be submerged, but the intake does.  Water can be lifted about 32 feet at sea level in a siphon before the water starts to separate in the pipe, the maximum height is a function of atmospheric pressure at your location.  

You can figure out any method you want to prime the siphon, but it should allow free flow when it’s off.  The siphon will operate until the intake is at the water surface and air gets in. 

If you place an adjustable valve in the line, it would be possible to keep the flow running as the flow rate requires adjustment, as long as there’s still flow coming in.  If the valve is placed at the discharge end, you can shut it off to maintain the prime before the intake gets exposed to air.  This should be something you can rig up with a feedback controller using depth of water as the input and valve position as output.  

If you form a slight horn shape, flared out at the end of the discharge pipe, right after the valve, the flow through the pipe will increase slightly vs. a sharp cut.  Also, use long radius elbows to reduce pipe friction.

I’m a professional engineer.  Good luck with your project.  A siphon will save you a lot of electricity cost.