Quote:
Originally posted by jtroutma
A SMALL amount of pressure, YES, but a LOT of pressure, NO.
Our pumps are designed so that if something restricts the line, the impeller will just sit there and thurn water. In other pumps which are designed for high pressure systems, if the exit is blocked, the pump will either: burn out due to extreme stress, or cause an impeller to fracture or pump casing to crack, OR be releaved by a releif valve.
ONLY systems designed for pressure have to worry about these problems. (such as in hydrolic systems)
Remember that you can create pressure by forcing more volume into a smaller space but in our setups, its only possible to go up the our pumps rated head pressure.
Head Pressure = NO resistance; how much water can you force up that outlet with nothing attached.
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Head pressure will be rated in PSI (or some similar unit) - how much water you can force up that outlet would be measured in GPH (or some similar unit). Those two things are not the same.
To go back to my favorite electrical analogies - our pumps are small batteries (low voltage, low pressure). If you hook even a small battery up with no resistance (eg. short it out), it will put out a LOT of current (likely fry itself) - if you hook up even one of our small pumps with no resistance, it will move a lot of water.
But really - all pumps are very similar - they create pressure (PSI), not volume (GPH). And a pump doesn't create pressure by pushing water into a small space - a pump creates pressure by transfering electrical energy into mechanical energy and exerting that energy on a fluid (and pressure is stored energy). Forcing more volume through a smaller tube creates more speed (MPH) for the same volume (GPH), and soon gmat will likely post up the formula that shows how to calculate them all based on one-another.
The reason we don't worry about pressure with our pumps, is because they are all mag-drive. The impeller is physically disconnected from the motor, connected only through a magnetic field. If the impeller gets stuck the motor can continue to turn, and so it doesn't burn out. Pressure is irrelivant - though typically a mag-drive system will produce lower pressure because the motor can't exert it onto the impeller without a physical connection.
Edit: I'm out for the day - gotta go do a lot of cooling-unrelated stuff before everything closes.