"Jeepers" <moomesa@INVALIDfnbnet.net> wrote in message
news:moomesa-594292.10590024112004@news-east.newsfeeds.com...
| In article <30jsckF3182ubU1@uni-berlin.de>,
| "Ray Drouillard" <cosmicpam2@comcast.net> wrote:
|
| > you will want to have a valve to keep the water from running out through
the pump and
| > back into the barrel that's in the truck.
| > Ray Drouillard
|
| Same for the top fill hole hose? Won't want to run backwards?
|
| I'm gonna use the top fill hole anyway so I don't have to disconnect the
| drain hose from the cabin.
|
| I lost the physics argument, but I had the right idea.

Put a "T" at the bottom with a check valve to the pump side. Pump all the
water in you want without back flow to the pump.

BTW that's the way it's been done with municipal water tower for years.

 

"Jeepers" <moomesa@INVALIDfnbnet.net> wrote in message
news:moomesa-594292.10590024112004@news-east.newsfeeds.com...
| In article <30jsckF3182ubU1@uni-berlin.de>,
| "Ray Drouillard" <cosmicpam2@comcast.net> wrote:
|
| > you will want to have a valve to keep the water from running out through
the pump and
| > back into the barrel that's in the truck.
| > Ray Drouillard
|
| Same for the top fill hole hose? Won't want to run backwards?
|
| I'm gonna use the top fill hole anyway so I don't have to disconnect the
| drain hose from the cabin.
|
| I lost the physics argument, but I had the right idea.

Put a "T" at the bottom with a check valve to the pump side. Pump all the
water in you want without back flow to the pump.

BTW that's the way it's been done with municipal water tower for years.

 

"Mike Romain"

| So if you have a pump that can only generate 'say' 50 psi, then your
| truck tank will fill up at a rate of 50 psi out of that 'say' 100 psi
| line if there is no backflow valve.

PSI is pressure a static number, flow rate (which is effected somewhat by
PSI) is another matter.

If your head generates 100 psi then a 50 psi pump will not work.

 

"Mike Romain"

| So if you have a pump that can only generate 'say' 50 psi, then your
| truck tank will fill up at a rate of 50 psi out of that 'say' 100 psi
| line if there is no backflow valve.

PSI is pressure a static number, flow rate (which is effected somewhat by
PSI) is another matter.

If your head generates 100 psi then a 50 psi pump will not work.

 

"Mike Romain"

| So if you have a pump that can only generate 'say' 50 psi, then your
| truck tank will fill up at a rate of 50 psi out of that 'say' 100 psi
| line if there is no backflow valve.

PSI is pressure a static number, flow rate (which is effected somewhat by
PSI) is another matter.

If your head generates 100 psi then a 50 psi pump will not work.

 

Correct

"James Gemmill" <gemmilljim@hotmail,com> wrote in message
news:cv5aq0d7v2dm85t2mlhm44itoa5jo903cm@4ax.com...
> On Wed, 24 Nov 2004 18:21:07 -0500, "mabar"
> <mabar@NoooSpamgrbonline.com> wrote:
>
> If, and only if, the tanks are of the same height. If the million
> gallon tank is taller there will be more pressure.
> >Tom

 

Correct

"James Gemmill" <gemmilljim@hotmail,com> wrote in message
news:cv5aq0d7v2dm85t2mlhm44itoa5jo903cm@4ax.com...
> On Wed, 24 Nov 2004 18:21:07 -0500, "mabar"
> <mabar@NoooSpamgrbonline.com> wrote:
>
> If, and only if, the tanks are of the same height. If the million
> gallon tank is taller there will be more pressure.
> >Tom

 

Correct

"James Gemmill" <gemmilljim@hotmail,com> wrote in message
news:cv5aq0d7v2dm85t2mlhm44itoa5jo903cm@4ax.com...
> On Wed, 24 Nov 2004 18:21:07 -0500, "mabar"
> <mabar@NoooSpamgrbonline.com> wrote:
>
> If, and only if, the tanks are of the same height. If the million
> gallon tank is taller there will be more pressure.
> >Tom

 

lazolla@hotmail.com (Bartolomeo Cristofori) wrote in message news:<93a0508e.0411241244.70fbb744@posting.google. com>...
> The physics is simple.
>
> If the hose is of the proper diameter for the flow rate generated by
> the pump, then the pressure at the pump will be about equal to the
> vertical distance (the height) between the pump and the point where
> the water becomes free-flowing, times a density value of about .45
> PSI/ft (which is derived from the weight of a cubic foot of water
> divided by 144 to convert from square feet to square inches). If you
> are pumping the water to the top of the barrel and letting it fall,
> then that would be the height difference between the pump and the top
> of the barrel. If you are pumping the water into the bottom bung,
> then you would use the height difference between the pump and the top
> of the water in the barrel.
>
> Therefore, the pump would encounter slightly less pressure if the tank
> were filled through the bottom bung, at least until it became nearly
> full. The difference is small enough that it would make only a small
> change in the amount of time it would take to fill the tank.
>
> The fact that there may be several hundred pounds of water in the
> barrel is immaterial, since pressure is pounds per square inch. You
> could calculate the pressure at the bottom of the barrel by dividing
> the weight of the water in the barrel by the area of the barrel head
> in square inches (assuming straight sides, for a wooden barrel you
> would have to use an average diameter to get an exact figure).
>
> Bartolomeo

Ah yes, finally the proper answer, i.e, it is slightly less pressure
to begin with to fill thru the bottom hole until it is identical when
the barrel is full. Assuming the barrel is about 4' high there would
be about 2psi differential pumping pressure at the bottom of the empty
barrel than at shutoff when it is full. Filling through the top hole
will have the same pressure of whatever throughout the filling.

Harry K

 

lazolla@hotmail.com (Bartolomeo Cristofori) wrote in message news:<93a0508e.0411241244.70fbb744@posting.google. com>...
> The physics is simple.
>
> If the hose is of the proper diameter for the flow rate generated by
> the pump, then the pressure at the pump will be about equal to the
> vertical distance (the height) between the pump and the point where
> the water becomes free-flowing, times a density value of about .45
> PSI/ft (which is derived from the weight of a cubic foot of water
> divided by 144 to convert from square feet to square inches). If you
> are pumping the water to the top of the barrel and letting it fall,
> then that would be the height difference between the pump and the top
> of the barrel. If you are pumping the water into the bottom bung,
> then you would use the height difference between the pump and the top
> of the water in the barrel.
>
> Therefore, the pump would encounter slightly less pressure if the tank
> were filled through the bottom bung, at least until it became nearly
> full. The difference is small enough that it would make only a small
> change in the amount of time it would take to fill the tank.
>
> The fact that there may be several hundred pounds of water in the
> barrel is immaterial, since pressure is pounds per square inch. You
> could calculate the pressure at the bottom of the barrel by dividing
> the weight of the water in the barrel by the area of the barrel head
> in square inches (assuming straight sides, for a wooden barrel you
> would have to use an average diameter to get an exact figure).
>
> Bartolomeo

Ah yes, finally the proper answer, i.e, it is slightly less pressure
to begin with to fill thru the bottom hole until it is identical when
the barrel is full. Assuming the barrel is about 4' high there would
be about 2psi differential pumping pressure at the bottom of the empty
barrel than at shutoff when it is full. Filling through the top hole
will have the same pressure of whatever throughout the filling.

Harry K