WATER

1
WATER PROPERTIES
By Robert Charney, January 2006
2
CHARACTERISTIC STATES OF WATER
3
SOLID
4
LIQUID
5
Vapor
6
VAPOR
7
The Water Molecule

• Water is composed of one Oxygen atom and two
  atoms of Hydrogen orientated on an axis of
  approximately 105 degrees

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The Water Molecule

• The Positive charged Hydrogen is attracted to the
  Negatively charged Oxygen

9
The Water Molecule

• Water has the molecular formula H2O but the
  hydrogen atoms are constantly exchanging due to
  protonation/deprotonation processes.
• These exchanges are catalyzed by both acids and
  bases even when at their slowest reactivity (at
  pH 7), the average residence time is about a
  millisecond.
• This period is brief, however, water is usually
  treated as a permanent structure.
• Much longer timescales are encountered during
  investigations into water's hydrogen bonding or
  hydration properties.

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The Water Molecule
This shows the tetrahedrality of the bonding in
spite of the lack of clearly seen lone pair
electrons although a small amount of distortion
along the hydrogen bond can be seen.
11
The Water Molecule
12
Density
Water has a specific gravity of one to which
other liquids density is compared. Water is most
dense at 4 degrees Celsius or 39.2 degrees
Fahrenheit
13
Weight of Water

• One Liter weighs one Kilogram
• One U.S. gallon weighs 8.34 pounds
• One Imperial gallon weighs 10 pounds
• One cubic foot weighs 62.42 pounds
• One cubic meter weighs 1000 Kilograms

14
Pressure

• A one foot high water column with a base of one
  inch square weighs 0.434
• Rule of thumb one foot water column equals ½ PSI

15
Pressure

• One Pound of pressure is created by a water
  column 2.31 feet high

The total force is increased directly
proportionally to the area in square inches of
the base of the water column. Pressure remains
constant and is directly proportional to the
height of the water column (head).
16
Pressure

• A column of water one meter high creates a
  pressure of 9.8 Kilopascals (Kpa)

17
Affects of heat

• One British Thermal Unit is required to raise the
  temperature of One pound of water 1 degree
  Fahrenheit
• Hardness deposition is increased with increased
  temperature above 100 F
• Water boils at 100 Celsius/ 212 Fahrenheit
• Water freezes at 0 Celsius/ 32 Fahrenheit
• Water expands from the most dense temperature of
  4 C, as heat is gained or lost
• One cubic inch of water becomes one cubic foot of
  water vapor (1728 cubic inches of steam)

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Useful Water Relationships

• One Imperial gallon equals 277 cubic inches
• One U.S. gallon equals 231 cubic inches
• Mercury is 13.6 times as dense as water
• Water requires 144 BTUs of Latent heat to change
  state from solid to liquid (no change in
  temperature)
• Water requires 970 BTUs of Latent heat to change
  state from a liquid to a vapor (no change in
  temperature)
• Sensible Heat is a temperature change that can be
  indicated on a thermometer
• One cubic foot of natural gas equals 1000 BTUs/
  hour
• One Kilowatt equals 3413 BTUs/ hour

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Water Formulas

• Area
• rectangle length x width
• Circle pie x radius x radius
• Cylinder pie x diameter x length
• Volume
• rectangle length x width x height
• Cylinder Pie x radius x radius x length

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Water Formulas

• Required BTUs Temperature change x pounds of
  water
• Boiling point square root of the PSI x 14 198
• Change in volume of air due to pressure Volume
  1 x Pressure 1V2P2 V3P3
• For calculation of draw down (each pressure is
  required to be expressed in absolute psi so add
  14.7 (atmospheric weight). Additionally include
  precharge in P1 only if determining draw from a
  diaphram tank

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Draw Down

• 40 gallon precharged (28 PSI) pressure tank
  operating _at_ 30/50 PSI
• V1P1V2P2V3P3 (in absolute pressure)
• 40(2814.7)V2(14.730)V3(14.750)
• 170844.7V264.7V3
• V21708/44.738.21
• V31708/64.726.39
• Draw downV2-V311.81 gallons

22
Thermal
Expansion

• Heating water causes water to expand from 4
  Celsius requiring provisions within a closed loop
  system for storage or relief.
• Water expands about 1/23 of volume when heated
  from 32F to 212F
• Gallons x Temperature Change x 0.00023 40 Imp
  Gallons x 95 degree change x 0.00023 0.874
  Imperial Gallons

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Tempered Water Formula
105F Mixed _at_ 8GPM
35F change
60F change
95F difference
140F Hot
45 F Cold
60/95 x 8 5.05 gallons per minute hot
35/95 x 8 2.95 cold