Auto-Fill Flooded Suction?

RickDelta

leonz said:

You need the right pump, they can show you what 4" pump will work and work well.

I have all the pumps! : )
573 Auto-fill/back flow preventer just came in this morning (thanks to HotRod)

I finished the core hole drilling last night ..... total 20ft of 3" holes thru 16" concrete!

Starting to run pipe now.

ChrisJ

@RickDelta
Out of curiosity, what do you think "Self priming" actually means?

A centrifugal pump isn't going to pump air no matter what special super powers it claims. Certainly not enough to pull water up 12 feet of pipe.

Pumpguy

Rick,

Before you consider using your $25 auction pump, see if you can get a copy of its performance curve.

If the pump is 12' above the water surface, you will have a 12' WC vacuum on the suction side of the pump. Thats about a 6" Hg. vacuum.

The pump you have may not be suitable for operation under these conditions.

Now, if you use self priming pumps, they are designed for these conditions, so creating the lift and operating under these conditions shouldn't be a problem.

RickDelta

ChrisJ said:

@RickDelta
Out of curiosity, what do you think "Self priming" actually means?

A centrifugal pump isn't going to pump air no matter what special super powers it claims. Certainly not enough to pull water up 12 feet of pipe.

....... I'm not trying to have it pump "air" ever! .... suction line is 24/7 flooded.

RickDelta

Pumpguy said:

Rick,

Before you consider using your $25 auction pump, see if you can get a copy of its performance curve.

If the pump is 12' above the water surface, you will have a 12' WC vacuum on the suction side of the pump. Thats about a 6" Hg. vacuum.

The pump you have may not be suitable for operation under these conditions.

Now, if you use self priming pumps, they are designed for these conditions, so creating the lift and operating under these conditions shouldn't be a problem.

There is NO air in suction line ..... 24/7 flooded

"D" profile curve is my pump

RickDelta

Pumpguy said:

Rick,

Before you consider using your $25 auction pump, see if you can get a copy of its performance curve.

If the pump is 12' above the water surface, you will have a 12' WC vacuum on the suction side of the pump. Thats about a 6" Hg. vacuum.

The pump you have may not be suitable for operation under these conditions.

Now, if you use self priming pumps, they are designed for these conditions, so creating the lift and operating under these conditions shouldn't be a problem.

"Out of curiosity, what do you think "Self priming" actually means?"

I believe its a pumps ability the expel air within its suction line (creating a vacuum) and the atmospheric pressure (14.7psi) pushes the water up to the pumps propelling vanes.

ChrisJ

RickDelta said:

Rick, Before you consider using your $25 auction pump, see if you can get a copy of its performance curve. If the pump is 12' above the water surface, you will have a 12' WC vacuum on the suction side of the pump. Thats about a 6" Hg. vacuum. The pump you have may not be suitable for operation under these conditions. Now, if you use self priming pumps, they are designed for these conditions, so creating the lift and operating under these conditions shouldn't be a problem.

"Out of curiosity, what do you think "Self priming" actually means?" I believe its a pumps ability the expel air within its suction line (creating a vacuum) and the atmospheric pressure (14.7psi) pushes the water up to the pumps propelling vanes.

I've never seen a centrifugal pump that could create enough of a vacuum to do that.  Especially single stage.

Even "self priming" pool pumps need water.

@Pumpguy please feel free to correct me as I'm far from an expert.

RickDelta

ChrisJ said:

RickDelta said:

Rick,

Before you consider using your $25 auction pump, see if you can get a copy of its performance curve.

If the pump is 12' above the water surface, you will have a 12' WC vacuum on the suction side of the pump. Thats about a 6" Hg. vacuum.

The pump you have may not be suitable for operation under these conditions.

Now, if you use self priming pumps, they are designed for these conditions, so creating the lift and operating under these conditions shouldn't be a problem.

"Out of curiosity, what do you think "Self priming" actually means?"

I believe its a pumps ability the expel air within its suction line (creating a vacuum) and the atmospheric pressure (14.7psi) pushes the water up to the pumps propelling vanes.

I've never seen a centrifugal pump that could create enough of a vacuum to do that.  Especially single stage.

Even "self priming" pool pumps need water.

@Pumpguy please feel free to correct me as I'm far from an expert.

I'm haven't the knowledge to correct you! : )

..... but I suggest my method has eliminated the need for a vacuum in the suction line to pump water ...... its being feed a steady supply (flooded) of what it does best, pumps water!

Its an "Hydraulic" interface.

As far as the pump knows, it's sitting in the water!

...... you do know I'm using foot check valve in the suction line .....right? (the pumps vanes are always under water even when off)

ChrisJ

@RickDelta

Yes that part I'm understanding.

I think the concerns others have mentioned are whether or not that pump can pull water up 12 feet period, with it being primed and all.



With it sitting in water it would have slightly positive pressure at the inlet.

ChrisJ

Actually after thinking about it for a while id bet cavitation is going to be a huge issue and besides resulting in terrible performance will also destroy the pump.

RickDelta

ChrisJ said:

@RickDelta

Yes that part I'm understanding.

I think the concerns others have mentioned are whether or not that pump can pull water up 12 feet period, with it being primed and all.



With it sitting in water it would have slightly positive pressure at the inlet.

" ......With it sitting in water it would have slightly positive pressure at the inlet."

..... Only til the pump ramps up! (then 50 PSI discharge pressure)

RickDelta

ChrisJ said:

Actually after thinking about it for a while id bet cavitation is going to be a huge issue and besides resulting in terrible performance will also destroy the pump.

....... have you considered the "aiding" pressure assist of the "siphonic" discharge will add?

Think: .... a cabled elevator with its counter weight cancelling out its enormous payload (then it only requires the motor/pump with much less power (differential) to move/flow water)

High pressure differential = cavitation!

leonz

A single cable mine hoist does not have a counterweight other than the weight of the hoist and the hoists concrete foundation.

A double drum mine hoist for hoisting finished ore uses the opposite skip for a counterweight by employing an over under wire lay where one hoist drum has the single lay wire rope layed over the top of the hoist drum and the single lay wire rope on the opposite hoist drum is laid under the drum.

An Otis counter weighted elevator like the four units used at the CN Tower in Toronto employs a track rail that raises the elevator car and lowers the weight blocks with a small diameter single lay sheave wheel grooved pulley that does not store the less than 700 feet of hoist rope for each elevator.
The combined weight of the elevator car and passengers is equal to or greater than the weight block
assembly and the hoist rope.

Please read pages 1-4 of the Masosine pumps information sheets on centrifugal pumps.

RickDelta

leonz said:

A single cable mine hoist does not have a counterweight other than the weight of the hoist and the hoists concrete foundation.

A double drum mine hoist for hoisting finished ore uses the opposite skip for a counterweight by employing an over under wire lay where one hoist drum has the single lay wire rope layed over the top of the hoist drum and the single lay wire rope on the opposite hoist drum is laid under the drum.

An Otis counter weighted elevator like the four units used at the CN Tower in Toronto employs a track rail that raises the elevator car and lowers the weight blocks with a small diameter single lay sheave wheel grooved pulley that does not store the less than 700 feet of hoist rope for each elevator.
The combined weight of the elevator car and passengers is equal to or greater than the weight block
assembly and the hoist rope.


Please read pages 1-4 of the Masosine pumps information sheets on centrifugal pumps.

......... this is a great read!! Thank-you Leonz!

leonz

The above was the reason I suggested that the 4 inch flap valve sandpiper diaphragm pumps be used with your needed water removal needs as they can move massive amounts of water at low operating pressure and make very little noise as long as they are used with an inlet stabilizer and surge dampener and you could have operated all of them with your computer a float valve and a PLC and kept them away from the building in that shed with an air compressor.

Jamie Hall

Oh dear. Well, a self-priming pump -- and they are commonly used in agricultural and construction fields -- is when referred to that way a centrifugal pump (note that several types of positive and semi-positive displacement pumps are also self-priming, but no usually described that way). The distinguishing feature of these pumps is a moderately large water reservoir stored in the volute and communicating with the intake. Upon starting the pump, this stored water will create a vacuum at the intake, which will -- with patience -- draw water from a lower source and fully fill the intake and the pump chamber itself.

Something of the same effect can be had if the intake has a foot valve, assuming the valve doesn't leak down.

Now cavitation. Cavitation will occur any time the pressure at some point in the impeller drops below the local boiling point of the water. This usually occurs right at the eye of the impeller. It has nothing to do with pressure differential across the pump, but the static pressure is an important consideration, as are the difference in water elevation between the intake source and the pump inlet together with any hydraulic losses on the way. Every centrifugal pump has a definite minimum net positive suction head pressure which must be maintained to avoid cavitation, but note that that is an absolute, not gauge, pressure. It will be in the pump specifications. I might add that cavitation can be a serious problem even in pump designs or other designs where the delta P is actually quite small -- a good example being ships' propellors.

RickDelta

leonz said:

The above was the reason I suggested that the 4 inch flap valve sandpiper diaphragm pumps be used with your needed water removal needs as they can move massive amounts of water at low operating pressure and make very little noise as long as they are used with an inlet stabilizer and surge dampener and you could have operated all of them with your computer a float valve and a PLC and kept them away from the building in that shed with an air compressor.

...... I have a problem with if were starting off with any solution that requires extensive "noise suppression" in a motel environment. Putting the noise making equipment far away as you suggested would be very costly.

Lets say I did take your path's solution , and the rhythmic diaphragm pump noise transmits to the piping, ever so slightly ........... this would result in a 100% fatal system loss as its un-recoverabale.

RickDelta

Jamie Hall said:

Oh dear. Well, a self-priming pump -- and they are commonly used in agricultural and construction fields -- is when referred to that way a centrifugal pump (note that several types of positive and semi-positive displacement pumps are also self-priming, but no usually described that way). The distinguishing feature of these pumps is a moderately large water reservoir stored in the volute and communicating with the intake. Upon starting the pump, this stored water will create a vacuum at the intake, which will -- with patience -- draw water from a lower source and fully fill the intake and the pump chamber itself.

Something of the same effect can be had if the intake has a foot valve, assuming the valve doesn't leak down.

Now cavitation. Cavitation will occur any time the pressure at some point in the impeller drops below the local boiling point of the water. This usually occurs right at the eye of the impeller. It has nothing to do with pressure differential across the pump, but the static pressure is an important consideration, as are the difference in water elevation between the intake source and the pump inlet together with any hydraulic losses on the way. Every centrifugal pump has a definite minimum net positive suction head pressure which must be maintained to avoid cavitation, but note that that is an absolute, not gauge, pressure. It will be in the pump specifications. I might add that cavitation can be a serious problem even in pump designs or other designs where the delta P is actually quite small -- a good example being ships' propellors.

"Upon starting the pump, this stored water will create a vacuum at the intake, which will -- with patience -- draw water from a lower source and fully fill the intake and the pump chamber itself."

I think to say " this stored water will create a vacuum....." is terribly un-explaining of the principal of how the vacuum is being formed.
I have 1,500 gallons of stored water in basement here .... and its creating NO vacuum at all!

I'll venture to guess that is much the same way my vacuum pump I use to pull down (vacuum) my refrigerant freon lines. Instead of water, they use an oil to seal a pump chamber while aspirating the pipes (directional pressure differential displacement)

This I'm sure, because if I don't expel the air from a self-priming pump chamber.... it can't produce a vacuum.


My contention in all this is that the hardest part (work) is to get the water into the pumps rotating vanes so it can pump a liquid and not a gas (air).

If I use a foot valve, that 24/7 floods the suction and discharge pipes, I see no need for any vacuum. Water is pumped immediately!! .... no vacuum wait time!

I believe the pump starts pumping immediately "siphonically" .... or "hydraulically" is the reason for this.

.... your thoughts?

NOTE:
I am not referring to its point of conversion to a vapor (cavation)

Mustangman

To me, this seems like a job for a freak drive. You can massage the performance of the pump by changing the frequency and voltage. No more short cycles just varying RPMs. I haven't given much thought as to how to control it. Possibly floats maybe a wet switch or switches. I am sure you could find a few ways to control it. The big advantage is no short cycles and the adjustments can be very fine. You can adjust pressure and or flow.
We have installed many larger well pumps where we buy a freak drive package. A 60 - 40 pressure switch isn't for everyone... they want the same pressure ... all the time. You can watch the control and gauges and see and hear the drive adjusting to a desired pressure. You can watch it ramp up and down, depending on usage.
I don't have all the bits and pieces of what you may need to pull this off. I am sure the pump people can help you out on that.
Steve

Jamie Hall

Without showing you a self-priming pump in person, there's clearly no way I can explain how they work to you. So I won't even try.

RickDelta

"@ChrisJ"
"Yes that part I'm understanding.
I think the concerns others have mentioned are whether or not that pump can pull water up 12 feet period, with it being primed and all."


My self-priming pump can prime itself to just over 20 feet of suction rise and then pump 300 gallons per minute.

Why don't you think a centrifugal couldn't do the same? A self-priming pump is a centrifugal pump too!

ChrisJ

RickDelta said:

"@ChrisJ"
"Yes that part I'm understanding.
I think the concerns others have mentioned are whether or not that pump can pull water up 12 feet period, with it being primed and all."


My self-priming pump can prime itself to just over 20 feet of suction rise and then pump 300 gallons per minute.

Why don't you think a centrifugal couldn't do the same? A self-priming pump is a centrifugal pump too!

Try it.
If it works, great.

But I have a feeling it'll sound like it's pumping rocks.

leonz

RickDelta said:

leonz said:

The above was the reason I suggested that the 4 inch flap valve sandpiper diaphragm pumps be used with your needed water removal needs as they can move massive amounts of water at low operating pressure and make very little noise as long as they are used with an inlet stabilizer and surge dampener and you could have operated all of them with your computer a float valve and a PLC and kept them away from the building in that shed with an air compressor.

...... I have a problem with if were starting off with any solution that requires extensive "noise suppression" in a motel environment. Putting the noise making equipment far away as you suggested would be very costly.

Lets say I did take your path's solution , and the rhythmic diaphragm pump noise transmits to the piping, ever so slightly ........... this would result in a 100% fatal system loss as its un-recoverabale.

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

The properly charged inlet stabilizer and the properly charged surge dampener would eliminate this entirely providing an even flow of water.

From Warren Rupp

www.sandpiperpump.com/parts-accessories

youtube.com/watch?v=xqKtgym2N4U

youtube.com/watch?v=80s3fzSGu08
-not sure if the z should be a (2) instead

youtube.com/watch?v=wBVxQr_ekYU

youtube.com/watch?v=XqKtgym2N4U&

The sandpiper pumps we used pumped millions of gallons salt water brine uphill out of a deep mine shaft sump for thousands of feet to old mined out areas for its disposal.


If a pair of precast cesspools and round base was placed below grade near the drain pipes and wrapped in landscape fabric you could pump all your water out below grade away from the hotel and have a dry basement.

RickDelta

leonz said:

RickDelta said:

leonz said:

The above was the reason I suggested that the 4 inch flap valve sandpiper diaphragm pumps be used with your needed water removal needs as they can move massive amounts of water at low operating pressure and make very little

Intplm. said:

Flooded suction. That means that the pump would be below the water line from which it is drawing water.This way the pump would stay primed.
If I understand you correctly, you are planning to have water piped to circulate from the suction to the discharge maintaining the pumps prime?
That can work if you have a proper water supply and properly installed check valves on the suction and discharge.
Im I following your thoughts? Or am I in error?

no! auto-fill valve to keep the prime

hot_rod

A call or email to AMT pump to go over your intended use could save some potential heart break

https://amtpumps.com/site/

RickDelta

ChrisJ said:

RickDelta said:

Rick,

Before you consider using your $25 auction pump, see if you can get a copy of its performance curve.

If the pump is 12' above the water surface, you will have a 12' WC vacuum on the suction side of the pump. Thats about a 6" Hg. vacuum.

The pump you have may not be suitable for operation under these conditions.

Now, if you use self priming pumps, they are designed for these conditions, so creating the lift and operating under these conditions shouldn't be a problem.

"Out of curiosity, what do you think "Self priming" actually means?"

I believe its a pumps ability the expel air within its suction line (creating a vacuum) and the atmospheric pressure (14.7psi) pushes the water up to the pumps propelling vanes.

I've never seen a centrifugal pump that could create enough of a vacuum to do that.  Especially single stage.

Even "self priming" pool pumps need water.

@Pumpguy please feel free to correct me as I'm far from an expert.

"@ChrisJ"

"I've never seen a centrifugal pump that could create enough of a vacuum to do that. Especially single stage."

Your right! They can't! That's why I'm not using a vacuum to lift the water up 12 feet.

The inlet and outlet ports are already filled with water! (flooded).

The pump is sitting in the stuff it pumps best ..... water!

hot_rod

The graph you posted answers the question. The column on the right, for the D series pump it looks like you need 32' (13.8 psi) NPSHr

Net Pump Suction Head, the r suffix is for "required"

Do a search for NPSH, lots of videos and graphics explaining the concept.

RickDelta

RickDelta said:

ChrisJ said:

RickDelta said:

Rick,

Before you consider using your $25 auction pump, see if you can get a copy of its performance curve.

If the pump is 12' above the water surface, you will have a 12' WC vacuum on the suction side of the pump. Thats about a 6" Hg. vacuum.

The pump you have may not be suitable for operation under these conditions.

Now, if you use self priming pumps, they are designed for these conditions, so creating the lift and operating under these conditions shouldn't be a problem.

"Out of curiosity, what do you think "Self priming" actually means?"

I believe its a pumps ability the expel air within its suction line (creating a vacuum) and the atmospheric pressure (14.7psi) pushes the water up to the pumps propelling vanes.

I've never seen a centrifugal pump that could create enough of a vacuum to do that.  Especially single stage.

Even "self priming" pool pumps need water.

@Pumpguy please feel free to correct me as I'm far from an expert.

"@ChrisJ"

"I've never seen a centrifugal pump that could create enough of a vacuum to do that. Especially single stage."

Your right! They can't! That's why I'm not using a vacuum to lift the water up 12 feet.

The inlet and outlet ports are already filled with water! (flooded).

The pump is sitting in the stuff it pumps best ..... water!




"@ChrisJ"

Hey ChrisJ!

Just some feed back:

I installed that centrifugal (Non- self priming) pump with a foot valve tonight.

Inlet pipe 15ft below pump in basement well.
Pump at street level.
Outlet pipe 12ft vertical over pump then 90 degrees horizontal down and out.

I fully primed the inlet and outlet pipes with water.

Turned on pump and it pumped the water immediately!!
Smooth running and with no perceptible cavitation.


..... tomorrow i'll install an auto-fill valve to "auto-prime" should I ever loose prime to this pump.

RickDelta

@ChrisJ

https://forum.heatinghelp.com/discussion/comment/1797520#Comment_1797520

ChrisJ

@RickDelta ?

RickDelta

sorry! ……. this was about a question if I could make a standard pump emulate a self-priming pump ……. with this pump 15 ft above the intake water line.

I just added a foot check and an auto fill valve (in case the foot valve ever leaked its suction prime).

The auto-fill unit keeps the water level 6ft high in the discharge pipe.

For the same HP of my self-priming pumps ……. this standard pump,pumps 100 GPM more than the self-priming pumps.

20240429_202000.jpg

Works great automatically every time! : )

PC7060

https://forum.heatinghelp.com/discussion/comment/1820424#Comment_1820424

impressive work Rick! I’m waiting with anticipation for the outcome of the motel sewer dilemma and the demise of the big condenser!
🍿🍿🍿