Is there a way to make a return act like a Vortech?

[Len]

I admittedly didn't let it run super long (wasn't a continuous application), but all I know is when i switched to 1", it worked right away.

Here's how I theorized it: You have a pump that moves 1000gph rated through it's 1" in and out. If you use 2" tubing, you'll still be moving 1000gph, but over 4x the cross diameter. This means lower velocity, but I think it also means a lot less maximum vertical height (i doubt it's loss of a factor of 4 though). When you're running horizontal, this isn't an issue.

Nope. It is pumps and fluids 101.

1. Pressure in a column of water is the same at a give depth regardless of cross section.
2. A pump's output (volumetric flow rate) is goverened by back pressure at the nozzel which is the height the water is pumped+ losses due to flow velosity+difference in pressure at the inlet and oulet.

This is what I don't get. You have a pump. Without any pipe, it shoots water about 5 feet into the air. You pipe the output and you can get it to pump higher. How does this factor into the equation?

 

[Anonymous]

Thanks Dan, that's really helpful! I might just ask them for a custom job. 8)

While you're here, could you explain what Mark and Len are talking about? I just keep hearing this whooshing sound above my head. :lol:

 

[Anonymous]

I admittedly didn't let it run super long (wasn't a continuous application), but all I know is when i switched to 1", it worked right away.

Here's how I theorized it: You have a pump that moves 1000gph rated through it's 1" in and out. If you use 2" tubing, you'll still be moving 1000gph, but over 4x the cross diameter. This means lower velocity, but I think it also means a lot less maximum vertical height (i doubt it's loss of a factor of 4 though). When you're running horizontal, this isn't an issue.

Nope. It is pumps and fluids 101.

1. Pressure in a column of water is the same at a give depth regardless of cross section.
2. A pump's output (volumetric flow rate) is goverened by back pressure at the nozzel which is the height the water is pumped+ losses due to flow velosity+difference in pressure at the inlet and oulet.

This is what I don't get. You have a pump. Without any pipe, it shoots water about 5 feet into the air. You pipe the output and you can get it to pump higher. How does this factor into the equation?

There are some nozzel equations that address how far water will shoot with a give outlet pressure and flow. Not something I spent lots of time with so I can not speak off the cuff.

 

[Anonymous]

Thanks Dan, that's really helpful! I might just ask them for a custom job. 8)

While you're here, could you explain what Mark and Len are talking about? I just keep hearing this whooshing sound above my head. :lol:

Condensed for Tom

Use a larger pipe and/or more outlets (not a spray bar) to get a lower velosity more distributed flow with out changing the flow rate (gph). Don't use to many or the water will come out so slow you will get no mixing in the tank.

 

[Len]

:lol:

I could be wrong. I'm just bouncing theory off Mark. I just remember running my Iwaki one time, and it wouldn't operate at the height I wanted with a larger diameter pipe, so I figured it's something like your faucet where if you restrict the flow a bit (like with your fingers), you can get it to shoot farther but at a much higher velocity.

 

[Anonymous]

Thanks both of you. Apologies for the non-scientist in the room.

 

[Anonymous]

:lol:

I could be wrong. I'm just bouncing theory off Mark. I just remember running my Iwaki one time, and it wouldn't operate at the height I wanted with a larger diameter pipe, so I figured it's something like your faucet where if you restrict the flow a bit (like with your fingers), you can get it to shoot farther but at a much higher velocity.

In this case you are wrong.

Like most you are confusing volumetric flow rate (gph) with flow veolsity (ft/sec). People generally gauge volumetric flow rate by observing the flow velosity. While they are related they are not the same. Your fauctet example is just that. By reducing the outlet with your finger you are increasing the velosity with out changeing the volume. That is why it shoots further.

 

[Len]

:lol:

I could be wrong. I'm just bouncing theory off Mark. I just remember running my Iwaki one time, and it wouldn't operate at the height I wanted with a larger diameter pipe, so I figured it's something like your faucet where if you restrict the flow a bit (like with your fingers), you can get it to shoot farther but at a much higher velocity.

In this case you are wrong.

Like most you are confusing volumetric flow rate (gph) with flow veolsity (ft/sec). People generally gauge volumetric flow rate by observing the flow velosity. While they are related they are not the same. Your fauctet example is just that. By reducing the outlet with your finger you are increasing the velosity with out changeing the volume. That is why it shoots further.

I realize that at the pump output level, the volume doesn't change, just the velocity. But at height, doesn't it change? I mean, without restricting the flow, the pump will only do 5' vertical. So at 6', the volume is zero. But if you restrict the flow with piping, the pump now does 10' now'; Doesn't it mean the volume has changed at every point form 5' to 10'?

 

[Anonymous]

This is what I don't get. You have a pump. Without any pipe, it shoots water about 5 feet into the air. You pipe the output and you can get it to pump higher. How does this factor into the equation?

Its because the pipe holds the water together in shape, it has a particular output that's governed by a constant flow, its not like there's one big push at one end and all the water goes at once

 

[Len]

Then wouldn't it make sense that if you use too big a pipe, at distance X, there's going to be less structured flow, with some water creating turbulence, thus reducing gph?

 

[Anonymous]

:lol:

I could be wrong. I'm just bouncing theory off Mark. I just remember running my Iwaki one time, and it wouldn't operate at the height I wanted with a larger diameter pipe, so I figured it's something like your faucet where if you restrict the flow a bit (like with your fingers), you can get it to shoot farther but at a much higher velocity.

In this case you are wrong.

Like most you are confusing volumetric flow rate (gph) with flow veolsity (ft/sec). People generally gauge volumetric flow rate by observing the flow velosity. While they are related they are not the same. Your fauctet example is just that. By reducing the outlet with your finger you are increasing the velosity with out changeing the volume. That is why it shoots further.

I realize that at the pump output level, the volume doesn't change, just the velocity. But at height, doesn't it change? I mean, without restricting the flow, the pump will only do 5' vertical. So at 6', the volume is zero. But if you restrict the flow with piping, the pump now does 10' now'; Doesn't it mean the volume has changed at every point form 5' to 10'?

You are talking two different things. Flow in a pipe act a certian way and nozzel flow acts in another. With a nozzel there is nothing holding the water together it disburses.

 

[Anonymous]

Then wouldn't it make sense that if you use too big a pipe, at distance X, there's going to be less structured flow, with some water creating turbulence, thus reducing gph?

The larger the pipe the less turbulent the water flows, keeping the same gph, geometry and surface conditions.

 

[Len]

So if I take a pump that has 1" outlet, are you saying that it will move the same volume of water at 10' vertical height regardless if I use 1/2" pipe of 4" pipe, just at different velocity?

 

[Len]

Then wouldn't it make sense that if you use too big a pipe, at distance X, there's going to be less structured flow, with some water creating turbulence, thus reducing gph?

The larger the pipe the less turbulent the water flows, keeping the same gph, geometry and surface conditions.

My thinking is if the pipe is the same size as the pump outlet, water will all be pushed uniformly in one direction until there's too much head pressure. If the pipe is bigger, water could start to "fold" back on itself creating turbulence.

 

[Anonymous]

So if I take a pump that has 1" outlet, are you saying that it will move the same volume of water at 10' vertical height regardless if I use 1/2" pipe of 4" pipe, just at different velocity?

No, it will actually move more water (gph) in the larger pipe to a certian extent. In 10ft you probably would not notice the diference. In 1000 ft you would. Here is why in a table.

 

[Anonymous]

Then wouldn't it make sense that if you use too big a pipe, at distance X, there's going to be less structured flow, with some water creating turbulence, thus reducing gph?

The larger the pipe the less turbulent the water flows, keeping the same gph, geometry and surface conditions.

My thinking is if the pipe is the same size as the pump outlet, water will all be pushed uniformly in one direction until there's too much head pressure. If the pipe is bigger, water could start to "fold" back on itself creating turbulence.

Right at the pump outlet it will. Once the flow settles it will move faster in the center and slower at the wall due to friction. If it is going slow enough. In cross section it kind of looks like a bell curve. to get that to happen you have to go really slow with the velosity. Generally most flow is turbulent (whole pipe moving at roughly the same velosity profile with lots of mixing). They have a bunch of equations to where you can calculate the theortecal flow rate for a give pipe size to get lamaner flow.

 

[Len]

So if I take a pump that has 1" outlet, are you saying that it will move the same volume of water at 10' vertical height regardless if I use 1/2" pipe of 4" pipe, just at different velocity?

No, it will actually move more water (gph) in the larger pipe to a certian extent. In 10ft you probably would not notice the diference. In 1000 ft you would. Here is why in a table.

Ya, I understand friction loss. But if you have a pipe that is, say, 12" on a pump with a 1" output, it's pretty much like having no pipe at all. Sure, there's virtually no friction loss, but the water isn't going to go as high as a smaller diameter pump. It'll move the same amount of volume at the pump's output, but not at all heights. But I guess between 1" and 1 1/2", it shouldn't behave that much differently (though it did with my Iwaki 30RLXT )

 

[Anonymous]

Thanks Dan, that's really helpful! I might just ask them for a custom job. 8)

While you're here, could you explain what Mark and Len are talking about? I just keep hearing this whooshing sound above my head. :lol:

That's the sound of a return being made to act like a Vortech.

















Thank you. Thank you. I'll be here all week.



Tom, what if you fed the water into a reverse overflow kind of setup? Wouldn't that diffuse the flow enough without reducing it too significantly?

 

[Anonymous]

So if I take a pump that has 1" outlet, are you saying that it will move the same volume of water at 10' vertical height regardless if I use 1/2" pipe of 4" pipe, just at different velocity?

No, it will actually move more water (gph) in the larger pipe to a certian extent. In 10ft you probably would not notice the diference. In 1000 ft you would. Here is why in a table.

Ya, I understand friction loss. But if you have a pipe that is, say, 12" on a pump with a 1" output, it's pretty much like having no pipe at all. Sure, there's virtually no friction loss, but the water isn't going to go as high as a smaller diameter pump. It'll move the same amount of volume at the pump's output, but not at all heights. But I guess between 1" and 1 1/2", it shouldn't behave that much differently (though it did with my Iwaki 30RLXT )

It's like having no pipe until it fills with water, then it it a really big pipe. The volumetric flow of the pump will be more in the larger pipe because of less friction. The diamer of the pipe does nothing to the pressure the pump sees. Only the height matters to the pressure.

Between the 1" and 1.5" the flow in the 1" will be faster they should pump to the same height.

 

[Len]

So if I take a pump that has 1" outlet, are you saying that it will move the same volume of water at 10' vertical height regardless if I use 1/2" pipe of 4" pipe, just at different velocity?

No, it will actually move more water (gph) in the larger pipe to a certian extent. In 10ft you probably would not notice the diference. In 1000 ft you would. Here is why in a table.

Ya, I understand friction loss. But if you have a pipe that is, say, 12" on a pump with a 1" output, it's pretty much like having no pipe at all. Sure, there's virtually no friction loss, but the water isn't going to go as high as a smaller diameter pump. It'll move the same amount of volume at the pump's output, but not at all heights. But I guess between 1" and 1 1/2", it shouldn't behave that much differently (though it did with my Iwaki 30RLXT )

It's like having no pipe until it fills with water, then it it a really big pipe. The volumetric flow of the pump will be more in the larger pipe because of less friction. The diamer of the pipe does nothing to the pressure the pump sees. Only the height matters to the pressure.

Between the 1" and 1.5" the flow in the 1" will be faster they should pump to the same height.

Height matters for pressure, but wouldn't a bigger volume pipe cause more energy dissipation? All the water that isn't moving one direction isn't causing more head pressure, but it is causing energy to be wasted. I can't imagine all water flows as uniformly in a bigger pipe as it does in a smaller pipe. But i don't know how much friction offsets this either. All I know is I could pump higher with 1" pipe then 1 1/2" pipe (over the span of about 20 minutes).