Jeepers proclaimed:

> In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
> "c" <c@me.org> wrote:
>
>
>>My physics is a bit rusty here, but IIRC, the pressure created at the bottom
>>opening will be equal to the weight of a water column (which is the area of
>>the opening x the height of the water column). This applies whether the
>>bottom opening is at the side or on the bottom. A fluid exerts equal
>>pressure against all sides of its container that it is in contact with. What
>>this means in essence is that it would take slightly less energy to bottom
>>fill. Any fluid in a container has some amount of stored energy, The wider
>>and shorter the container is, the less energy it will take to fill it.
>>
>>Also, like the others said, the energy required to top fill will remain
>>constant as the barrel fills. For bottom filling, the energy will start out
>>slightly less, and end up the same as the barrel reaches full.
>>
>>Chris
>
>
> O.K. my lame-*** attempt at physics argument:
>
> Isn't part of the column the barrel? The barrel has a bigger column in
> it's part, than the hose. So the weight of the water column is GREATLY
> larger than the one in the hose going to the top. Less water - less
> weight, right?
>
Nope. Height matters, width doesn't. Presuming the top has been
vented to the atmosphere.

 

Jeepers proclaimed:

> In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
> "c" <c@me.org> wrote:
>
>
>>My physics is a bit rusty here, but IIRC, the pressure created at the bottom
>>opening will be equal to the weight of a water column (which is the area of
>>the opening x the height of the water column). This applies whether the
>>bottom opening is at the side or on the bottom. A fluid exerts equal
>>pressure against all sides of its container that it is in contact with. What
>>this means in essence is that it would take slightly less energy to bottom
>>fill. Any fluid in a container has some amount of stored energy, The wider
>>and shorter the container is, the less energy it will take to fill it.
>>
>>Also, like the others said, the energy required to top fill will remain
>>constant as the barrel fills. For bottom filling, the energy will start out
>>slightly less, and end up the same as the barrel reaches full.
>>
>>Chris
>
>
> O.K. my lame-*** attempt at physics argument:
>
> Isn't part of the column the barrel? The barrel has a bigger column in
> it's part, than the hose. So the weight of the water column is GREATLY
> larger than the one in the hose going to the top. Less water - less
> weight, right?
>
Nope. Height matters, width doesn't. Presuming the top has been
vented to the atmosphere.

 

default@uri.edu proclaimed:

>>Nope. When we speak of a column in this context, the column has the
>>same area as the hose through which you're pumping fluid. If you
>>wanted to know the pressure in pounds per square inch, you'd consider
>>an imaginary coulumn with a cross-sectional area of 1 square inch.
>
>
> Shouldn't it be the area of whatever piston, diaphram, or whatever
> you're moving the water with, in the pump? The hose is just
> a weirdly shaped part of the reservior you're pumping water into.

Nope. That only matters if you want to calculate how many linear
feet of water moving up the hose it will take to make the depth
inside the barrel rise by one inch.

 

default@uri.edu proclaimed:

>>Nope. When we speak of a column in this context, the column has the
>>same area as the hose through which you're pumping fluid. If you
>>wanted to know the pressure in pounds per square inch, you'd consider
>>an imaginary coulumn with a cross-sectional area of 1 square inch.
>
>
> Shouldn't it be the area of whatever piston, diaphram, or whatever
> you're moving the water with, in the pump? The hose is just
> a weirdly shaped part of the reservior you're pumping water into.

Nope. That only matters if you want to calculate how many linear
feet of water moving up the hose it will take to make the depth
inside the barrel rise by one inch.

 

default@uri.edu proclaimed:

>>Nope. When we speak of a column in this context, the column has the
>>same area as the hose through which you're pumping fluid. If you
>>wanted to know the pressure in pounds per square inch, you'd consider
>>an imaginary coulumn with a cross-sectional area of 1 square inch.
>
>
> Shouldn't it be the area of whatever piston, diaphram, or whatever
> you're moving the water with, in the pump? The hose is just
> a weirdly shaped part of the reservior you're pumping water into.

Nope. That only matters if you want to calculate how many linear
feet of water moving up the hose it will take to make the depth
inside the barrel rise by one inch.

 

Don Bruder proclaimed:

> In article <moomesa-6BB8BB.12550424112004@news-east.newsfeeds.com>,
> Jeepers <moomesa@INVALIDfnbnet.net> wrote:
>
>
>>In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
>> "c" <c@me.org> wrote:
>>
>>
>>>My physics is a bit rusty here, but IIRC, the pressure created at the bottom
>>>opening will be equal to the weight of a water column (which is the area of
>>>the opening x the height of the water column). This applies whether the
>>>bottom opening is at the side or on the bottom. A fluid exerts equal
>>>pressure against all sides of its container that it is in contact with. What
>>>this means in essence is that it would take slightly less energy to bottom
>>>fill. Any fluid in a container has some amount of stored energy, The wider
>>>and shorter the container is, the less energy it will take to fill it.
>>>
>>>Also, like the others said, the energy required to top fill will remain
>>>constant as the barrel fills. For bottom filling, the energy will start out
>>>slightly less, and end up the same as the barrel reaches full.
>>>
>>>Chris
>>
>>O.K. my lame-*** attempt at physics argument:
>>
>>Isn't part of the column the barrel? The barrel has a bigger column in
>>it's part, than the hose. So the weight of the water column is GREATLY
>>larger than the one in the hose going to the top. Less water - less
>>weight, right?
>
>
> I'm with you on this one -
> The barrel has a lager cross-section than the hose. Much like the
> pistons in a kiddie-toy-simple two-ram hydraulic system - Big piston
> pushes on fluid, sending it throrugh the lines to wherever the work
> needs to be done, where it presses against a smaller piston. Thethe
> smaller piston can be seeing *RIDICULOUSLY HUGE* amounts of pressure
> from a very light pressure being applied to the larger piston (The
> multiplication of force effect that comes from the larger piston
> displacing more fluid)

Except that this is totally irrelevant. Only if you are working where
you put pressure on the water in the barrel...say by forgetting to
open the top vent.
>
> My take on this is that filling from the top would put take less effort
> from the pump - Rather than needing to fight both its own "head" (The
> size of the tube multiplied by the height it's climbing, if I remember
> rightly) AND the "head" in the barrel, the pump only has to push against
> it's own head until it's above the highest point of the barrel, where
> gravity takes over and delivers it the rest of the way.
>
> Pumping to the bottom of the barrel means a steadily increasing head in
> the barrel as the barrel gets fuller. To go with the head developed in
> the fill hose. The pump has to overcome that "total head" to get
> anything more into the barrel.
>
> How to test this theory:
> Put a pressure gauge at the lowest point of the system after the pump -
> right at the pump outlet would be ideal. Now fill the hose with water
> (You'll probably have to block the pump's intake to get any reading at
> all), and raise it into posiiton to fill from the top. What's the gauge
> say?
>
> Now hook the hose to the bottom bung, make sure it's full of water, then
> pump until the top barrel is full. Shut down the pump and block the
> intake as before, and read the gauge. What's it say now?
>
> My nickel says that the "from the bottom" setup is going to show a
> higher PSI than the setup to fill from the top.
>

 

Don Bruder proclaimed:

> In article <moomesa-6BB8BB.12550424112004@news-east.newsfeeds.com>,
> Jeepers <moomesa@INVALIDfnbnet.net> wrote:
>
>
>>In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
>> "c" <c@me.org> wrote:
>>
>>
>>>My physics is a bit rusty here, but IIRC, the pressure created at the bottom
>>>opening will be equal to the weight of a water column (which is the area of
>>>the opening x the height of the water column). This applies whether the
>>>bottom opening is at the side or on the bottom. A fluid exerts equal
>>>pressure against all sides of its container that it is in contact with. What
>>>this means in essence is that it would take slightly less energy to bottom
>>>fill. Any fluid in a container has some amount of stored energy, The wider
>>>and shorter the container is, the less energy it will take to fill it.
>>>
>>>Also, like the others said, the energy required to top fill will remain
>>>constant as the barrel fills. For bottom filling, the energy will start out
>>>slightly less, and end up the same as the barrel reaches full.
>>>
>>>Chris
>>
>>O.K. my lame-*** attempt at physics argument:
>>
>>Isn't part of the column the barrel? The barrel has a bigger column in
>>it's part, than the hose. So the weight of the water column is GREATLY
>>larger than the one in the hose going to the top. Less water - less
>>weight, right?
>
>
> I'm with you on this one -
> The barrel has a lager cross-section than the hose. Much like the
> pistons in a kiddie-toy-simple two-ram hydraulic system - Big piston
> pushes on fluid, sending it throrugh the lines to wherever the work
> needs to be done, where it presses against a smaller piston. Thethe
> smaller piston can be seeing *RIDICULOUSLY HUGE* amounts of pressure
> from a very light pressure being applied to the larger piston (The
> multiplication of force effect that comes from the larger piston
> displacing more fluid)

Except that this is totally irrelevant. Only if you are working where
you put pressure on the water in the barrel...say by forgetting to
open the top vent.
>
> My take on this is that filling from the top would put take less effort
> from the pump - Rather than needing to fight both its own "head" (The
> size of the tube multiplied by the height it's climbing, if I remember
> rightly) AND the "head" in the barrel, the pump only has to push against
> it's own head until it's above the highest point of the barrel, where
> gravity takes over and delivers it the rest of the way.
>
> Pumping to the bottom of the barrel means a steadily increasing head in
> the barrel as the barrel gets fuller. To go with the head developed in
> the fill hose. The pump has to overcome that "total head" to get
> anything more into the barrel.
>
> How to test this theory:
> Put a pressure gauge at the lowest point of the system after the pump -
> right at the pump outlet would be ideal. Now fill the hose with water
> (You'll probably have to block the pump's intake to get any reading at
> all), and raise it into posiiton to fill from the top. What's the gauge
> say?
>
> Now hook the hose to the bottom bung, make sure it's full of water, then
> pump until the top barrel is full. Shut down the pump and block the
> intake as before, and read the gauge. What's it say now?
>
> My nickel says that the "from the bottom" setup is going to show a
> higher PSI than the setup to fill from the top.
>

 

Don Bruder proclaimed:

> In article <moomesa-6BB8BB.12550424112004@news-east.newsfeeds.com>,
> Jeepers <moomesa@INVALIDfnbnet.net> wrote:
>
>
>>In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
>> "c" <c@me.org> wrote:
>>
>>
>>>My physics is a bit rusty here, but IIRC, the pressure created at the bottom
>>>opening will be equal to the weight of a water column (which is the area of
>>>the opening x the height of the water column). This applies whether the
>>>bottom opening is at the side or on the bottom. A fluid exerts equal
>>>pressure against all sides of its container that it is in contact with. What
>>>this means in essence is that it would take slightly less energy to bottom
>>>fill. Any fluid in a container has some amount of stored energy, The wider
>>>and shorter the container is, the less energy it will take to fill it.
>>>
>>>Also, like the others said, the energy required to top fill will remain
>>>constant as the barrel fills. For bottom filling, the energy will start out
>>>slightly less, and end up the same as the barrel reaches full.
>>>
>>>Chris
>>
>>O.K. my lame-*** attempt at physics argument:
>>
>>Isn't part of the column the barrel? The barrel has a bigger column in
>>it's part, than the hose. So the weight of the water column is GREATLY
>>larger than the one in the hose going to the top. Less water - less
>>weight, right?
>
>
> I'm with you on this one -
> The barrel has a lager cross-section than the hose. Much like the
> pistons in a kiddie-toy-simple two-ram hydraulic system - Big piston
> pushes on fluid, sending it throrugh the lines to wherever the work
> needs to be done, where it presses against a smaller piston. Thethe
> smaller piston can be seeing *RIDICULOUSLY HUGE* amounts of pressure
> from a very light pressure being applied to the larger piston (The
> multiplication of force effect that comes from the larger piston
> displacing more fluid)

Except that this is totally irrelevant. Only if you are working where
you put pressure on the water in the barrel...say by forgetting to
open the top vent.
>
> My take on this is that filling from the top would put take less effort
> from the pump - Rather than needing to fight both its own "head" (The
> size of the tube multiplied by the height it's climbing, if I remember
> rightly) AND the "head" in the barrel, the pump only has to push against
> it's own head until it's above the highest point of the barrel, where
> gravity takes over and delivers it the rest of the way.
>
> Pumping to the bottom of the barrel means a steadily increasing head in
> the barrel as the barrel gets fuller. To go with the head developed in
> the fill hose. The pump has to overcome that "total head" to get
> anything more into the barrel.
>
> How to test this theory:
> Put a pressure gauge at the lowest point of the system after the pump -
> right at the pump outlet would be ideal. Now fill the hose with water
> (You'll probably have to block the pump's intake to get any reading at
> all), and raise it into posiiton to fill from the top. What's the gauge
> say?
>
> Now hook the hose to the bottom bung, make sure it's full of water, then
> pump until the top barrel is full. Shut down the pump and block the
> intake as before, and read the gauge. What's it say now?
>
> My nickel says that the "from the bottom" setup is going to show a
> higher PSI than the setup to fill from the top.
>

 

No the size or the volume of the barrel is not part of the column. The
barrel could also be a lake, or any container. The only consideration is the
height difference between the top water level and the pump. The height
refers only to the water column which is a 1 square inch imaginary column to
the top of the water level at the top barrel, or the top of the lake, or
wherever the top end of the hose ends up.

Let's say the hose goes from the pump, up 40 feet to the top of the barrel.
Then the water pressure would be 40 x 0.43 psi = 17.2 psi. Now if the hose
makes a 180 degree turn at the top and goes down into the barrel 3 feet,
then after you pump the initial water to the top of the hose, the 3 feet of
siphon action of the water in the hose will cause the pressure to be 37 x
0.43 = 15.91 psi.

If the water level in the top barrel rises above the end of the hose (which
is at 37 feet) the pressure will increase according to the top of the water
level. Same formula: about 0.43 psi for every foot of height.

Another way to visualize water pressure: A diver at 100 feet deep in the
ocean experiences the exact same water pressure as a diver 100 feet deep in
a small swimming pool (if there were such a thing.) The volume of water does
not matter. The only thing that matters is the height of the imaginary 1
square inch water column.

Tom

"Jeepers" <moomesa@INVALIDfnbnet.net> wrote in message
news:moomesa-6BB8BB.12550424112004@news-east.newsfeeds.com...

> Isn't part of the column the barrel? The barrel has a bigger column in
> it's part, than the hose. So the weight of the water column is GREATLY
> larger than the one in the hose going to the top. Less water - less
> weight, right?
>
> --
> Member AAAAAAAA
> American Association Against Acronym Abuse And Also Ambiguity.
>
> ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet
News==----
> http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
> ----= East and West-Coast Server Farms - Total Privacy via Encryption
=----

 

No the size or the volume of the barrel is not part of the column. The
barrel could also be a lake, or any container. The only consideration is the
height difference between the top water level and the pump. The height
refers only to the water column which is a 1 square inch imaginary column to
the top of the water level at the top barrel, or the top of the lake, or
wherever the top end of the hose ends up.

Let's say the hose goes from the pump, up 40 feet to the top of the barrel.
Then the water pressure would be 40 x 0.43 psi = 17.2 psi. Now if the hose
makes a 180 degree turn at the top and goes down into the barrel 3 feet,
then after you pump the initial water to the top of the hose, the 3 feet of
siphon action of the water in the hose will cause the pressure to be 37 x
0.43 = 15.91 psi.

If the water level in the top barrel rises above the end of the hose (which
is at 37 feet) the pressure will increase according to the top of the water
level. Same formula: about 0.43 psi for every foot of height.

Another way to visualize water pressure: A diver at 100 feet deep in the
ocean experiences the exact same water pressure as a diver 100 feet deep in
a small swimming pool (if there were such a thing.) The volume of water does
not matter. The only thing that matters is the height of the imaginary 1
square inch water column.

Tom

"Jeepers" <moomesa@INVALIDfnbnet.net> wrote in message
news:moomesa-6BB8BB.12550424112004@news-east.newsfeeds.com...

> Isn't part of the column the barrel? The barrel has a bigger column in
> it's part, than the hose. So the weight of the water column is GREATLY
> larger than the one in the hose going to the top. Less water - less
> weight, right?
>
> --
> Member AAAAAAAA
> American Association Against Acronym Abuse And Also Ambiguity.
>
> ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet
News==----
> http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
> ----= East and West-Coast Server Farms - Total Privacy via Encryption
=----