|Posted by Gary Slusser on June 10, 2003 at 11:05:12:|
|In response to Re: Should I replace my pressure tank?|
: I have well water which is pumped into a 30 year old steel pressure tank. There is no separation between the air and water. I maintain the tank carefully, recharging it every 4 to 6 months. It runs 42PSI (pump on) to 62PSI (pump off). I get a drawdown of 8 gallons before the pump turns on. The pump was replaced 15 years ago.
: Here is my question. Should I replace this prefectly good, working tank with a larger precharged bladder tank? Since I get only approx 8 gallons between each pump cycle, I would like to decrease the amount of times the pump runs while increasing the amount of water per pump cycle. A 15 year old pump may not have too many cycles left in it and replacing it would be costly. I heard that the pressure tank should be sized based on the number of fawcets in your house. Doesn't it make sence to get the biggest tank possible so that you have more water per pump cycle? I have 14 fawcets in my house. What would you recommend I do? Leave the old tank alone? Replace it with a standard bladder type tank or replace it with the biggest tank I can buy?
You correctly size a pressure tank by one to two minuets of pump run time. The time depends on the HP of the pump; up to 1 hp 1 min..
Your well may not be able to produce say 30 gallons of water for each pump run if you have a LARGE tank. And if it can, the water quality can suffer and the pump will have to work harder as the water level falls in the well, if it does, and you use a lot of water over a short period of time.
Your present tank allows the air to dissolve into the water (while changing the water quality, hence the filters) and you lose drawdown gallons from the first fill until you redo the air in 4-6 months. You should have an air volume control on the tank that maintains the air vloume where it should be. Since it sounds as if you don't, a new captive air tank that provides at least 60 seconds pump run time, makes sense. Going to the next larger size would be fine and give you what you're trying for, longer pump life.