Difference between revisions of "Pumps"
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(see also tidied up) |
(→Flow & Head: hopefully a little clearer) |
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==Flow & Head== | ==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 operates against a column of water (or head) which provides back pressure | + | * The pump often operates against a column of water (or head) which provides back pressure |
* Pipes have resistance to water flow | * Pipes have resistance to water flow | ||
| − | A better idea of real life flow can be gained by plotting head versus flow rate on x | + | 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. |
===More Head Please=== | ===More Head Please=== | ||
Revision as of 13:29, 30 June 2007
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 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 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 water sensor
Drill Pump
- Small minimal cost pump for occasional clear-up use
Foul Water Pump
- Able to handle debris in the water