Roman Aqueduct w/Siphon lock?

RickDelta

leonz said:

Desk Reference Page 823 last column

Using 2 pumps with 4 inch basket strainers and 4' flap check valves,

A 50 foot section of schedule 40 3-inch PVC Pipe with an elbow and short piece of pipe in the sump raised slightly to drain into the sump would theoretically allow almost 574 gallons per minute of syphon flow into the sump once the pump or pumps start.

If the tilt switches were placed away from the sump in calm surface water in the basement mounted on a pressure treated 2" by 2" they would be more effective in controlling the pump or pumps and dewatering the basement.

As "109A_5" said ......"baby steps" here! ....... I agree!

My "Primary" pumping solution will always be the self-priming electric pumps.
If I can incorporate a "Pump + Siphonic" solution .... that would be awesome!

I will follow the path 109A_5 suggested ...."baby steps" Get the pumps up and running reliably, .... only then, begin testing the siphonic piping for any significant discharge contribution possible.

At all times ..... the electric pumps will be on the "Ready"


Foot note: (thinking

There will be times i'm sure, that I'll have a great siphon flow, but less than the ingress of water flow.
So, at high water level trip, lead pump turns on.
Since I have two 4" discharge pipes, one pipe will be discharging under electric pump pressure and the other pipe continues its siphonic discharge contribution with-out any power usage.

RickDelta

Just a lay-out here :

The 3" vertical discharge pipe and the suction pipes will have unions to be able to pull the pumps for service.
I was going to install a 3" full port ball valve above the discharge union to hold back the overhead standing water in there to service the pump.
But, all I really need to do is to install a small 3/4" drain cock in one of the bottom plugged ports on the pump body w/hose tail to drain in floor.

The pumps electrical will be pre-tailed 3ft motor cord w/twist lock plug ends

To service the foot valves (in bottom of small sump basin) .... open suction union, lift pipe up and out of sump basin from the pump room.
Go down to basement and the foot valves will be at eye level, out of the water for servicing.

I decided not to use the expensive mag GPM flow sensor, instead install two inexpensive pressure/vacuum sensors (one on suction side and one on discharge side).

Any flow issues would immediately alarm maintenance staff.

RickDelta

"@PaulFormisano"

.... It just occurred to me what you were saying about actively "regulating" the flow rate of the available siphonic discharge.

Throttle the siphon (via the PLC) to match the varying ingress of water. Never let the siphon "break" by discharging more than is coming in, always maintain a constant water level in the storage basin (that's 80% of the time here)

In leu of an expensive mag flow meter, simply use the "shallow" depth level sensor's digital pulse stream to accurately sample the varying water level to control the modulating discharge valve.

....... a"smart" siphonic discharge paradigm! : )

RickDelta

I think i'll need a combo "pressure/vacuum" gauge for the suction and discharge pump body plugged ports.
...... what pressure range would I need? (ie: -30 vacuum and +60 max. psi full scale)

Pump is an "AMT 2876-95 pump" at 30 ft TDH

leonz

Good morning Rick.

It is better to have a separate high quality gauge for vacuum measurement and a separate pressure measurement gauge for water the same size (3/4") as the upper pump case tapping.

Installing a 3" by " 3/4" short nipple, 3/4" elbow, 3/4" short nipple, 3/4" ball valve and a 3/4 plug(you can use the provided hex plug in the pump case for that) on your pumps for your pressure and vacuum measurements.

The American Water Works Association book "PUMPS AND PUMPING" 10th edition is an excellent reference/bible for everything about centrifugal pumps. $75.00

Pumpguy

RickDelta said:

I think i'll need a combo "pressure/vacuum" gauge for the suction and discharge pump body plugged ports.
...... what pressure range would I need? (ie: -30 vacuum and +60 max. psi full scale)

Pump is an "AMT 2876-95 pump" at 30 ft TDH

Compound vacuum/pressure gauges are available in graduations 30-0-15, 30-0-30, and 30-0-60. Maybe others too.

I agree with @leonz about sensitivity on the vacuum side of the scale. As the gauge goes higher on the pressure side, the sensitivity on the vacuum side decreases.

As with recommendations of Vaporstats vs Pressuretrols on steam boilers, I would suggest mounting separate vacuum and pressure gauges in parallel. Although with this arrangement, I can't guarantee the vacuum gauge won't get damaged when subjected to high pressures.

RickDelta

"@Pumpguy"

Thank you!

My original thoughts were to install a GMP flow sensor, NOT that I cared about the actual GPM discharge value, but to simply know if the pump was pumping water normally or something impeding its flow rate.

In presenting this question to AMT (pump manufacture) he said NO need to pressure sensor the suction line on a self-priming pump.

Just install a 0-50 psi pressure sensor on the discharge pipe!
Now, when you run your pump for the first time (while everything is new and unobstructed) note the developed discharge pressure. This pressure reading will indicate "all is well"

A blocked suction line drops this pressure
A blocked discharge increases this pressure
A locked rotor zero pressure

........ your thoughts?

leonz

RickDelta said:

"@Pumpguy"

Thank you!

My original thoughts were to install a GMP flow sensor, NOT that I cared about the actual GPM discharge value, but to simply know if the pump was pumping water normally or something impeding its flow rate.

In presenting this question to AMT (pump manufacture) he said NO need to pressure sensor the suction line on a self-priming pump.

Just install a 0-50 psi pressure sensor on the discharge pipe!
Now, when you run your pump for the first time (while everything is new and unobstructed) note the developed discharge pressure. This pressure reading will indicate "all is well"


A blocked suction line drops this pressure
True, but it also develops a vacuum.


A blocked discharge increases this pressure

Only slightly as it will cavitate since it is not a positive displacement gear, piston Diaphragm pump that will shatter the piping but it may blow the seal.


A locked rotor zero pressure
TRUE-kicked out circuit breaker.


........ your thoughts?

I would worry about starving the pump(s) at start up with this small sump pulling all the water in the sump out at once and the pumps cavitating every time you have a low water condition since the pump chambers have to be primed to start them if there is no foot valve.

Pumpguy

I don't get involved with self priming centrifugal pumps so I can't comment with authority.

That said, and if I understand your planned operating logic, you wouldn't be operating these pumps like a normal pitted sump pump. You wouldn't be starting a pump until the low tier has a certain level of water on the floor above the sump pit, and you would stop the pump when the level is in the pit, below the tier's floor. Am I correct here?

If yes, and if there's any depth at all, that volume of water above the tier's floor would be considerable and there would be no starvation of the pump's suction.

Also, I have no experience with flow sensors and what restriction they might cause. I would want to know though.

Now flow switches, that's a different matter. In short, I don't like them. Any momentary changes to the flow will cause chattering in the control circuit leading to unnecessary control problems.

Unless you have pressure that far exceeds the 12' WC, (5 or 6 PSI) its all downhill, literally, from there. If you're operating pumps that exceed the syphon flow rate of the pipe size, then yes, the pressure will be higher, but then you're defeating the whole syphon concept and just have a pumping application same as irrigation or similar.

RickDelta

"@Pumpguy"

That said, and if I understand your planned operating logic, you wouldn't be operating these pumps like a normal pitted sump pump. You wouldn't be starting a pump until the low tier has a certain level of water on the floor above the sump pit, and you would stop the pump when the level is in the pit, below the tier's floor. Am I correct here?


Yes! ...... (stop pump when bottom tier floor is empty, but leaving the original small sump basin full ....... "bang/bang" level control)


If yes, and if there's any depth at all, that volume of water above the tier's floor would be considerable and there would be no starvation of the pump's suction.

Correct!


Also, I have no experience with flow sensors and what restriction they might cause. I would want to know though.

Depends on the type! .... a turbine flow sensor (having a propeller) has more restriction than a magnetic flow sensor. I use a "water straightner" so the turbine blades don't rattle in the turbulence when needed. A pressure sensor is only a 1/4" hole in the side of the pipe and is not even in the flow's path! (no restrictions)

RickDelta

"@leonz"

I would worry about starving the pump(s) at start up with this small sump pulling all the water in the sump out at once and the pumps cavitating every time you have a low water condition since the pump chambers have to be primed to start them if there is no foot valve.

The 1,500 gallon sump basin you referring to?? : (


" ..... pulling all the water in the sump out at once and the pumps cavitating every time you have a low water condition ....."

The small sump is never emptied!
Pumps have foot valves and cages!
Pumps have a self-contained water reservoir to prime themselves! (even without the foot valves)

RickDelta

A blocked discharge increases this pressure

Only slightly as it will cavitate since it is not a positive displacement gear, piston Diaphragm pump that will shatter the piping but it may blow the seal.

Jamie Hall said:

There are so many options! I get a chuckle out of the flush idea -- that's a concept which has been used for at least a century on sewer systems with flat grades. The idea being to have a nice big tank at the upstream end which slowly fills (as you say, like a toiler) and then finally the siphon action starts and empties the tank -- whoosh -- and flushes out the sewer. Same concept for dosing siphons for larger septic leach fields, or ones in bad ground.

One which I haven't seen yet, if the space really is needed, is to use horizontal boring from the basement to run a really big enough pipe (say 8 inch maybe) from the sump straight out to daylight near the canal and forget all the fancy stuff. Not cheap, but I wonder if it really would be that much more expensive overall -- never mind the fact that gravity flow is pretty reliable... I've used that technique where you really don't want to dig a trench (under a railroad track for instance!) but you need to get from here to over yonder somewhere...

".......if the space really is needed, is to use horizontal boring from the basement to run a really big enough pipe (say 8 inch maybe) from the sump straight out to daylight near the canal and forget all the fancy stuff. Not cheap, but I wonder if it really would be that much more expensive overall "


........ haven't rented one for awhile, but its like $32,000.00 per hour rental ....... I'll go ask the motel owner here if thats good with him! : )

...... to have delivered to jobsite will cost ya more! (lot cheaper just to go pick it up yourself) : )







........ I don't think he was too crazy about the idea : (

Hey! ....... you guys looking for any help over there? : )

Jamie Hall

I guess the price has gone up since I last used one, about ten years ago... but by a factor of about 20? Seems a bit steep...

leonz

Youn rented a small track drive HDD UNIT and drilling mud cleaner for $32,000.00 an hour?????????????
What brand was it, BARCO, ACKERMAN, VERMEER?

Jamie Hall

The last time I used one it was a Vermeer. Two man crew, plus yours truly trying to look helpful. And nowhere near the price quoted above. But then, didn't have to go that far -- under a railroad track about a hundred feet or so, eight inch.

leonz

RickDelta said:

"@leonz"

I would worry about starving the pump(s) at start up with this small sump pulling all the water in the sump out at once and the pumps cavitating every time you have a low water condition since the pump chambers have to be primed to start them if there is no foot valve.

The 1,500 gallon sump basin you referring to?? : (


" ..... pulling all the water in the sump out at once and the pumps cavitating every time you have a low water condition ....."

The small sump is never emptied!
Pumps have foot valves and cages!
Pumps have a self-contained water reservoir to prime themselves! (even without the foot valves)

=================================================================

For what it's worth, I have had self priming centrifugal pumps starve themselves.
This is why I suggested that you lay a section of PVC pipe with an elbow and short drop pipe down and tip up the end of the pipe to create a siphon at pump start up.

RickDelta

"@109A_5"

I'm going to go with your recommendation and install a full port stop valve in the discharge pipes just above the unions.
I'll still put a small drain cock on the pump drain port with hose into drain for servicing as well.

Just above the discharge stop valve I'll install the discharge pressure sensor.
When that pump is sleeping, the 8 ft of vertical sitting water above the pump, I'll still "see" on the pressure sensor.

This will be a good indication of a leaking foot and check valve!

RickDelta

"@Leonz"

I added an "floating" OAK deck for a much stronger motor mounting base.
There are NO bolts or screws attaching this deck to the aluminum frame below. The deck does not contact the frame below.
Its floating on an 1/8" inch bed of heavy duty adhesive silicone on all the aluminum support rails acting as a "vibration" damper.

leonz

Please look at these AMT submersible sump pumps they are float controlled and designed for the extreme service you need. You would not have to keep them all in the existing sump and they can operate un-attended with no computer interface

Model No.5983-95 operates with 170 gallons per minute total head using 110 volts.
4 of them would pump 680 gallons per minute and you could push 340 gallons per minute through each pipe.