As I understand it, you count the entire run, length and depth from the
intake to the outlet...then add for the friction of the pipe and fittings.
Someone has info about it on their web site but for the life of me I can't
remember the url.

"BenignVanilla" m wrote in
message ...
My main pond has a bottom drain...which feeds a 4 inch pipe up to the VF.
When calculating the head do I need to consider the depth of the bottom
drain and calculate from there? or do I calculate from the water line?

--
BenignVanilla
Experience is something you don't get until just after you need it.
tibetanbeefgarden.com

Remove MYFRONTALLOBE to email me.

"BenignVanilla" m wrote in
message ...
When calculating the head do I need to consider the depth of the bottom
drain and calculate from there? or do I calculate from the water line?

No, the height at which water gets pumped up to is from the water line. The
pressure of the water in the ponds takes into account the part of the run
that is below the waterline. Friction of the 4 inch pipe may or may not be a
factor in the equation: If your VF is gravity-fed from the 4 inch drain,
then it's not a factor at all. Even if that's not the case, unless you are
pumping a lot of water there probably isn't much friction going on in a 4
inch pipe.


--
David Pochron

"David Pochron" wrote in message
...
"BenignVanilla" m wrote
in
message ...
When calculating the head do I need to consider the depth of the bottom
drain and calculate from there? or do I calculate from the water line?

No, the height at which water gets pumped up to is from the water line.
The
pressure of the water in the ponds takes into account the part of the run
that is below the waterline. Friction of the 4 inch pipe may or may not
be a
factor in the equation: If your VF is gravity-fed from the 4 inch drain,
then it's not a factor at all. Even if that's not the case, unless you
are
pumping a lot of water there probably isn't much friction going on in a 4
inch pipe.

My problem is that I made an gross error in the position of my VF...It is
higher then my reservoir...so water is draining from the VF to the pond. I
plan to put a check valve in tonight to stop this...My next test will be too
see if the pump can then manage to pull from the bottom drain in to the VF
properly. *sigh*

BV.

"John Hines" wrote in message
...
You'd want to watch out for uv on the liner though from the sun.

As I found out this year. :-( Didn't know the sun would shrink exposed
liner.


--
David Pochron