1. Convert 20 gpm to mgd
2. Convert 60 mph to ft/second
3. Convert 6000 cf to gallons
4. Convert 120 feet of static head into psi
5. Convert 14 acres into square feet
1. 20 gal/min X 1440 min/day = 28,800 gal/day OR 20 gal/min X 60 min/hr X 24 hr/day
(28,000 gal/day) / (1,000,000) = 0.0288 MGD
(20 gal/min) / (1440 min/day) / (1 mg/1,000,000 gal) = 0.0288 MGD
2. (60 mph) / (60 min/hr) = 1 m/min
(1 m/min) / (60 sec/min) = 0.0167 mile/sec
0.0167 mile/sec X 5280 ft/mile = 88 ft/sec
(60 miles/hr) / (1 hr/min) / (1 min/sec) / (5280 ft/1 mile) = 88 ft/sec
3. 6,000 cf X 7.48 gal/cuft = 44,800 gal
(6,000 cuft) / (7.78 gal/1 cuft) = 44,800 gal
4. 120 ft X 0.433 psi/ft = 51.96 psi
NOTE: The column exerts 0.433 pounds per square inch of pressure. One pound per square inch (psi) of pressure can be created using a 1-in. square column of water nearly 28 inches or 2.31 feet high.
5. 14 acres X 43,560 sf/acre = 609,840 sf
NOTE: Acre is 43,560 square feet. So, if you dig 1 foot deep over an acre, you get 43,560 cubic feet of dirt.
Hello i am need of a problem I can’t understand. I wanted to see if you can help me.
A pump is located at the bottom of a hill that is 175 feet tall. The pump is lifting water from a wet well (a below-ground storage tank) beneath the pump to another storage tank on top of the hill. The Total Dynamic Head on the pump is 240 feet, and it is experiencing a friction loss of 7 psi. The suction lift for the pump (from the wet well) is 5 psi. What is the reading on the pressure gauge at the bottom of the storage tank on top of the hill?
Thank you so much for reaching out to Wastewater 101, LLC.
I will tell you right up front – I am more familiar with Wastewater Math than Water Math, and numbers are numbers and formulas are formulas. With that said, it is important to pay attention to the process or you will end up like me and you will work it wrong. So, here is the way to work the problem through and the answer:
Convert the “feet” of the towers to PSI by dividing each by 2.31 psi/ft
The relationship between PSI and feet of head is that 2.31 feet of head = 1 PSI. Translated, that means that a column of water that’s 1 inch square and 2.31 feet tall will weigh 1 pound. Or, one foot column of water that’s 1 inch square weighs 0.433 pounds. These two numbers, 0.433 and 2.31, are the conversion numbers used to convert from one unit to the other.
(240 ft) / (2.31 psi/ft) = 105.9 psi
(175 ft) / (2.31 psi/ft) = 75.8 psi
Now you subtract = 105.9 psi – 75.8 psi – 7 psi – 5 psi = 16.1 psi
(NOTE) The reason it is so important to know a little more about the Water side to be able to work this out. I always say – when it doubt draw it out, but I worked it wrong myself, so I reached out to get the correct way to work it out. I did convert both the 240 ft and 175 ft to psi (have to have the correct units). Then I subtracted = 105.9 – 75.8 = 28.4 psi. But then I also subtracted = 7 – 5 = 2 psi. Then I subtracted again = 28.4 psi – 2 psi = 26.4 psi. So you can see for this one you need to understand the function of the formula and I didn’t have that knowledge.