Difference between revisions of "Pumps"

Revision as of 03:55, 30 January 2012

All about pumps. Please contribute & help complete the article.

Flow & Head

Marketing departments have a habit of claiming flow rate figure with no pipe attached to the output, and head figure at zero flow. These are both unrealistic conditions for real world use. In reality:

The pump often operates against a column of water (or head) which provides back pressure
Pipes have resistance to water flow

A better idea of real life flow can be gained by plotting head (at zero flow) versus flow rate (at zero head) on x & y axes, and drawing a straight line from max flow to max head. This enables approx flow rates to be read off for any given head. This does not take pipe resistance into account, which will lower flow rates further.

More info

More Head Please

Plumbing 2 pumps in series gives a total head of the 2 pumps added together.

Pump Power

Pump Materials

Brass: used for potable water
Plastics: some are approved for potable water

Connections

Pump Types

Central Heating circulator

Very quiet operation
Long service life
Speed adjustable.
- too fast can cause pumping over & noise
- too slow can cause boiler kettling
Standardised pipe fittings.

Shower

Boost shower pressure and thus flow
Boosts bills too.

Sump pump

For draining cellars prone to flooding.
Usually automatically operated by a built-in water sensor
Usually placed in a small dug out lowered area of floor to achieve good floor drainage.

Drill Pump

Small minimal cost pump for occasional clear-up use

Foul Water Pump

Able to handle debris in the water

@@ Line 7: / Line 7: @@
 * Pipes have resistance to water flow
-A better idea of real life flow can be gained by plotting head (at zero flow) versus flow rate (at zero head) on x & y axes, and drawing a straight line from max flow to max head. This enables flow rates to be read off for any given head. This does not take pipe resistance into account, which will lower flow rates further.
+A better idea of real life flow can be gained by plotting head (at zero flow) versus flow rate (at zero head) on x & y axes, and drawing a straight line from max flow to max head. This enables approx flow rates to be read off for any given head. This does not take pipe resistance into account, which will lower flow rates further.
+[http://groups.google.com/group/uk.d-i-y/browse_frm/thread/f73a5b1271ece66c# More info]
 ===More Head Please===