new here and have water pressure questions - DIY Chatroom

BAM · 10-22-2009, 12:38 PM

I am looking into installing a booster pump but not sure if that is exactly what will solve my problem or if I have pipe size/flow issues. Here is some background on my system.

The home is served with 1" copper and reduces to 3/4" thru meter and check valve and then is reduced again to a 1/2" header to feed the 1/2" branch connections. The home has lousy pressure, so bad that when the washer is filling the kitchen sink is useless. I have tested the pressure on an outside hose bibb at 27 psi.

The house is located on top of a hill and the city water storage tank is only a quarter mile up the road, roughly 15' in elevation difference. Does this sound like low pressure issues or is the 1/2" header the problem? Just to let you know most of my neighbors have some type of booster system in their homes. Any help would be greatly appreciated.

hayewe farm · 10-22-2009, 04:13 PM

You need a booster pump. Small tubing will cause low water flow but will not affect static pressure.

Yoyizit · 10-22-2009, 05:50 PM

Quote:

Originally Posted by BAM

I have tested the pressure on an outside hose bibb at 27 psi.

I thought values outside 30 to 80 PSI were against Code.
15' should give you a 7 PSI drop.
Check with the neighbors at lower altitudes.

Daniel Holzman · 10-22-2009, 06:56 PM

Yoyizit is right on the money, there should be less than 10 psi drop from the tank to your house if the elevation difference you refer to is the difference in ground level elevation. Assuming the water tank that is 1/4 mile away feeds your house, the pressure at the water tank should be around 100 psi, and you should have plenty of pressure at your house.

You need to check the pressure in the line before it enters your house, maybe the city has the records. The pressure at your hose bib reflects pressure on your side, and may not be representative of pressure available at the street. You could have a defective pressure reducing valve installed, or there could be an issue with the line from the city to your house.

BAM · 10-27-2009, 03:52 PM

thanks any other ideas? I checked my flow rate several times yesterday and it comes in at 4 gpm at my washer which is 12' from my water meter. Does this sound like a reasonable flow or what? I also should correct myself and the incoming serivce is 3/4" not 1". I do not currently have a prv installed and the city says the curb stop is fine and fully open. The main in the street is 16" D.I. I was looking into installing the Amtrol pressuriser system but specs say it requires 10 gpm from city. Is this strictly for pump durability or that the pressure boosting will not be as advertised? Right now I would be happy with 20 psi more. Any ideas?

cm3putter · 10-27-2009, 10:59 PM

Pressure at the tank is not 100psi.. pressure will be 0 at the water height in the tank (ignoring atmospheric pressure) and depending on the tank height, the pressure at the base of the tank will be equal to 1 psi per 2.31 feet of water column. If there is 15 elevation difference between your house and the water level in the tank as you suggested (I think it's much more than that) then the pressure at your house would be roughly 6.5 psi (15ft/2.31ft). If the pressure at your house is roughly 27 psi as you said you measured then the the elevation change between your house and the tank level would be about 62 feet (27psi x 2.31 ft) which I suspect is closer to the actual. Most state regs adopt a 20 psi minimum to be provided by local water provider at the meter.

That being said, you have bad hydraulics based on your location near the tank. The 16 inch line will give you all the flow you'll ever need... you just need a booster pump to "boost" the pressure to the house.

Daniel Holzman · 10-27-2009, 11:28 PM

cm, I think the OP meant that the elevation difference between the bottom of the tank and the grade at his house was 15 feet, not that the difference in elevation between the water in the tank and the water in his house was 15 feet. He said the tank was on a hill (typical for a water tank). The pressure in the water lines at the base of the tank is probably about 90 or 100 psi, that is pretty typical for municipal water systems. No one measures pressure at the top of the tank, you are correct it is always taken as atmospheric, unless you have the somewhat unusual case of a pressurized tank.

Assuming the pressure at the tank is OK, it make little sense that the water pressure would drop to less than 30 psi at the house. And the OP measured 4 gpm at the washing machine, which is pretty typical for a 1/2 inch copper line. I would check with the city to see what pressure they are delivering at the meter before I went out and bought a pressure increasing pump, the problem may be in the 1/2 inch distribution piping in the house.

cm3putter · 10-29-2009, 10:20 AM

thx DH.. understood.. I agree no one measures pressure at the top of the tank. I was simply stating, since the OP stated he lived on a hill, I didn't believe the tank was 231+ feet tall (necessary to produce 100 psi at the base). Tanks on hills typically are more in the range of 40-75 feet. If the OP recorded 27psi at his house and there's a 15 ft. elevation diff to the base of the tank, then the pressure at the base would be about 20.5 psi (6.5 psi change) making the tank about 48 feet tall which seems more logical. It would also explain why the OP stated most of his neighbors have a booster pump. Here in middle TN, our system has 13 tanks on hills, all in the 50-75 ft range. Any of our customers above a certain elevation are required to install a booster pump; and It just seems logical that the OP has a similar circumstance.

BAM · 10-29-2009, 04:48 PM

cm..I think you are on the right path and I have be told this same thing from others I was just trying to get more advice. I have a plumber coming Monday to give me an idea to resolve the issue. FYI, I believe the tank is roughly 55' high and the 15' difference I stated was base elevations. I talked to a neighbor at the base of the hill, roughly 60' in elevation difference from myself and they have no problems. Thanks for all help guys. Any experience with booster manufacturers or recommendations?

cm3putter · 10-29-2009, 05:44 PM

there are a lot of good pump manufacturers out there, I'd consult with a local reputable plumber or even a neighbor as to what might be best for you... fyi, just remember 1 psi is necessary to push water 2.31 feet so if your neighbor is about 60 ft down the hill, and your pressure is 27 psi, then their pressure will be about 53 psi or double yours (60 feet / 2.31 ft = 26 psi + your 27 psi = 53 psi).