It depends on how many people live in the home, and if it's only for the home or irrigation as well. -Generally a home of 4 people would need a 35 -50 gallon pressure tank. A small tank like 30 gall would work, but means your pump will come on more often, so better value to get a slightly bigger tank. Pumps are generally at least twice the cost of tank.
Which water tank, well water, cold storage or hot water heater tank.
If water doesn't go into the pressure tank you will not have water pressure.
If the height is 10' and the tank is full of water, you would have 4.33 lbs.
Water bladder tanks are tanks which contain a rubber bladder that is filled with either water or air. The majority of water bladder tanks have water-filled bladders. When a water faucet is turned on or a toilet is flushed, the water is piped in from the water tank. As the water pressure and air pressure get low, the contacts on the pressure switch click together. The pressure switch sends an electrical current to the water pump which causes the water pump to kick on and pipe water back into the water bladder tank. The amount of time it takes for the pressure switch to click on depends upon the size of the water bladder tank. The larger the water bladder tank, the longer it will be before the pressure switch starts to deliver electrical current to the water pump. Read more: How Does a Water Bladder Tank Work? | eHow.com http://www.ehow.com/how-does_5001805_water-bladder-tank-work.html#ixzz2A9TeSAnX found this on www.ehow.com
Physical size of a tank is irrelevant to it's pressure rating.
Water bladder tanks are tanks which contain a rubber bladder that is filled with either water or air. The majority of water bladder tanks have water-filled bladders. When a water faucet is turned on or a toilet is flushed, the water is piped in from the water tank. As the water pressure and air pressure get low, the contacts on the pressure switch click together. The pressure switch sends an electrical current to the water pump which causes the water pump to kick on and pipe water back into the water bladder tank. The amount of time it takes for the pressure switch to click on depends upon the size of the water bladder tank. The larger the water bladder tank, the longer it will be before the pressure switch starts to deliver electrical current to the water pump. Read more: How Does a Water Bladder Tank Work? | eHow.com http://www.ehow.com/how-does_5001805_water-bladder-tank-work.html#ixzz2A9TeSAnX found this on www.ehow.com
you cannot increase the pressure from a gravity tank by changing the pipe size, only the volume of water that will flow in a given period of time. The only way to increase the pressure is to increase the difference between the elevation of the tank and the elevation of the spigot. Many people will confuse an increase in water volume with an increase in water pressure, because, in both cases, more water will flow in a given period of time. ...moreincreasing the pipe size can reduce elevation loss due to friction which can translate in lay mans terms as an "increase in pressure"
residual air pressure in the tank, and the pressure switch settings
with a pressure tank and pressure switch
If you mean a well tank, the water is forced in by the pump. The residual air pressure pushes the water out to the faucets.
The water pressure depends on the residual air pressure in the tank. Normally it should be between 30 -50-psi. Tank air pressure is important, it should be about 27-29 when water is nearly empty.
First follow all water lines to make sure there secure, and if they are you should Install an expansion tank, they are sized by gallon, per water pressure and hot water tank size, pressure relief,heater temp. Check your water pressure and make sure your expansion tank is charged to the same pressure after you buy one. If you go to watts.com there is a nice calc for ex tank size. There is probably a check valve before or just after you water meter which does not allow for the expansion of the hot water heater and also you could have just over 40psi coming from your water authority, in which case those small arresters are not enough.