Impeller pumps
 

OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

Hi
I half there, I'm old. I'm not sure I understand. Do you have two
impellers? If you only have one the baldes are going to be in the same
direction no matter which way you turn it.



engsol wrote:
OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

On Tue, 25 Jan 2005 19:23:32 -0800, engsol
wrote:

OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

Here's my best guess:
impeller rotating clockwise:
impeller blades trail
Left port in
Right port out.

Brian W

I always thought the intake was in the center of these pumps, but I haven't
looked in a while so my memory may be failing me.

I do know that the vanes must always trail the rotation or they will tear
themselves up.

"Brian Whatcott" wrote in message
...
On Tue, 25 Jan 2005 19:23:32 -0800, engsol
wrote:

OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

Here's my best guess:
impeller rotating clockwise:
impeller blades trail
Left port in
Right port out.

Brian W

Oh yes, the impeller is ecentically mounted. See:
http://www.uaf.edu/seagrant/boatkeeper/water-pumps.pdf


"Brian Whatcott" wrote in message
...
On Tue, 25 Jan 2005 19:23:32 -0800, engsol
wrote:

OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

Here's my best guess:
impeller rotating clockwise:
impeller blades trail
Left port in
Right port out.

Brian W

Norm:
It is not really possible to answer your question with the information you
posted. The center of the drive shaft is offset from the center of the
impeller housing. Whichever side has the most volume will be the inlet and
the other side will be the outlet. Or another way of saying this is the side
closest to the drive shaft will be the outlet. The pumping action occurs as
the vane sweeps from a large volume to a smaller one. When you look at it
with the cover removed it will be obvious which way the vane turns to pump
once you understand the pumping mechanics. It would be best to orient the
vanes so they sweep out opposite to the rotation direction. If you install
the vanes the wrong way, don't worry, they will flip over on the first rev
or so.

I also coat the vanes with some non petroleum based lubricant like Lanacoat.

David
"engsol" wrote in message
...
OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

On Tue, 25 Jan 2005 20:06:13 -0800, "Johnhh"
wrote:

Oh yes, the impeller is ecentically mounted. See:
http://www.uaf.edu/seagrant/boatkeeper/water-pumps.pdf


"Brian Whatcott" wrote in message
.. .
On Tue, 25 Jan 2005 19:23:32 -0800, engsol
wrote:

OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

Here's my best guess:
impeller rotating clockwise:
impeller blades trail
Left port in
Right port out.

Brian W

If its like the eccentric rotor pump illustrated in John's URL,
the left port would be out, right port in.

Brian W

Away from the discharge. Even if you don't set them that way, they will set
themselves.

Cntrflm


"engsol" wrote in message
...
OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B

Put the new one in the same way the old one was when you took it out.
The vanes should always trail the direction of spin, e.g., if the pump turns
clockwise, the vanes should bend to the left, and vice-versa.

--


Keith
__
Take my advice; I'm not using it!
"engsol" wrote in message
...
OK, here's where you old salts can set me straight.
Visualize an impeller pump as being a T...with the vertical part of
the T being replaced by a circle, i.e., the impeller. Now assume the arms
of the the T are labeled IN/OUT (left) and OUT/IN.(right)

The question is...for a given rotation (direction) of the impeller,
which direction is the water going to flow..and which direction
should the impeller vanes be flopped...with the rotation or against
the rotation..if that makes sense.

An ancillerary question....before you install the pump, do you
need to fix the impeller vanes properly depending on the
anticipated rotation? And if you don't...what happens?

Thanks
Norm B