A.

Introduction
PLUMBING

- defined as the art and science of installing pipes, fixtures

and other apparatus to convey and supply water in
buildings and to dispose and discharge waste water and
other liquids, gases and other substances out of buildings
in a safe, orderly, healthy and sanitary way to ensure
health and sanitation of life and property.

Etymology of ‘Plumbing’

The term plumbing is derived from the Latin word plumbum

for lead (Pb), a metal used as plumbing material by the
Romans, preferred for its twin properties of malleability and
resistance to acid. Historians theorize that lead leaching into
drinking water from water supply pipes and lead from other
sources poisoned the Roman aristocracy, contributing to the
decline of the Roman Empire.

PLUMBER

- a title given to a person who is skilled in the field of sanitation.

Etymology of ‘Plumber’

It was derived from the ancient Roman word plumbarius (an individual who worked in the sanitary
field of ancient Rome) which was taken from the Latin word plumbum.

B. Tidbits from Plumbing History

Greeks

Nearly 4000 years ago, the ancient Greeks had hot and cold water systems in buildings. The Minoan
Palace of Knossos on the isle of Crete had terra cotta (baked clay) piping laid beneath the palace
floor. These pipes provided water for fountains and faucets of marble, gold, and silver that offered hot
and cold running water. Drainage systems emptied into large sewers constructed of stone. Surprisingly,
although hot and cold water systems were in place, for the Spartan warrior it was unmanly to use hot
water.

King Minos of Crete owned the world’s first flushing water closet with a wooden seat and a small
reservoir of water, over 2800 years ago.

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 King Minos of Crete

Romans

The Romans who considered daily bathing as a must, elevated bathing to the level of a daily ritual.
Their almost fanatical demand for a constant supply of clean water, found its expression in the ingenuity
of the now famous Roman Aqueduct, a water system that continuously challenge the skill of the
present crops of engineers.

Roman Aqueduct

The first storm sewers of Rome were built about 2800 years ago. Over 2000 years ago, the Romans
had in place highly developed community plumbing system in which water was conveyed over many
miles by large aqueducts. Water was then distributed to residences in lead pipes. By the 4th century
C.E., Rome had 11 public baths, over 1300 public fountains and cisterns, and over 850 private
baths.
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The Roman plumber was an artisan who worked with lead. Both male and female plumbers soldered,
installed, and repaired roofs, gutters, sewers, drains, and every part of the plumbing supply, waste, and
storm drainage systems.

The famous Goth invasion brought about the disintegration and eventual collapse of the Roman
Empire. The decline of the Roman Empire and an outbreak of deadly bubonic plague that killed an
estimated one-third of the European population during the Middle Ages resulted in the decline of
public baths and fountains. The period from 500 to 1500 C.E. was a dark age in terms of human
hygiene; community plumbing became almost non-existent. It was only during the Renaissance period
that interest in sanitation was again revived. At the end of the Middle Ages, London’s first water
system was rebuilt around 1500. It consisted partly of the rehabilitated Roman system with the
remainder patterned off of the Roman’s design.

Chinese

In the Far East, archaeologists in China recently uncovered an antique water closet in the tomb of a
king of the Western Han Dynasty (206 B.C.E.to 24 C.E.). It was complete with running water, a stone
seat, and a comfortable armrest.

Egyptians

Pumping devices have been an important way of moving fluids for thousands of years. The ancient
Egyptians invented water wheels with buckets mounted on them to move water for irrigation. Over
2000 years ago, Archimedes, a Greek mathematician, invented a screw pump made of a screw
rotating in a cylinder (now known as an Archimedes screw). This type of pump was used to drain and
irrigate the Nile Valley.

Archimedes Screw Pump

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England

In 17th century, the English parliament passed the first plumbing apprentice law. France followed
suit in 18th century when it embarked in the building of water service facilities.

The beginnings of modern plumbing began in the early 1800s, when steam engines became capable
of supplying water under pressure and inexpensive cast iron pipes could be produced to carry it.

Finally, it was through observation of several cholera epidemics in the mid-1800s that epidemiologists
finally recognized the link between sanitation and public health. This discovery provided the thrust
for modern water and sewage systems. In 1848, England passed the national Public Health Act,
which later became a model plumbing code for the world to follow. It mandated some type of sanitary
disposal in every residence such as a flushing toilet, a privy, or an ash pit.

America

In America, like Europe, colonial hygiene and sanitation were poor. Colonial bathing consisted of
infrequent baths in ponds or streams. New World settlers emulated the Native Americans’ discharge of
waste and refuse in running water, open fields, shrubs, or forests. As in Europe, colonials living in town
would empty their chamber pots by tossing excrement out the front door or window onto the street. As
early as 1700, local ordinances were passed to prevent people from throwing waste in a public street.
Eventually, use of the privy or outhouse slowly became accepted.

Drinking water in colonial America came from streams, rivers, and wells. It was commonly believed at
the time that foul-tasting mineral water had medicinal value. Around the time of the American
Revolution, Dr. Benjamin Rush, a signer of the Declaration of Independence and surgeon general
under George Washington, had the bad fortune of having a well with horribly tasting water at the site
of his Pennsylvania home. Townspeople rushed to his well to get drinking water in hopes that its
medicinal value would cure ailments. Unfortunately, when Dr. Rush’s well dried out from overuse, it
was discovered too late that the well was geologically connected underground to the doctor’s
privy.

In 1804, Philadelphia earned the distinction as the first city in the world to adopt cast iron pipe for
its water mains.

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 C. Plumbing in the Philippines
Before the decades of the 40’s, household
plumbing installation was considered a luxury item
available only to the upper crust of the society.
Majority of the population, aside from not being
able to afford plumbing installation in their homes,
were still not aware of the importance of sanitation
facilities in the form of an efficient water supply
and waste disposal system. Most of the
households, particularly in the rural areas, were
adopting the indigenous and ingenious methods
of water supply and waste disposal, unmindful of
the ill effects brought about by poor sanitation.

Water Supply
In the absence of an efficient water supply and distribution system, water was provided through:
1. rainfall
2. springs
3. wells
4. rivers
5. creeks
Water was conveyed through:
1. improvised bamboo pipes
2. man
3. animal drawn carts
4. sleds
Water was stored in:
1. earthen jars
2. wooden or bamboo containers
In those times, water was considered fit for consumption as long as it was visibly clear. There was no
available means to test the water for purity and absence of disease-causing organisms. As a result, not
a few died or were afflicted with digestive disorders. And those ailing were brought to quack doctors
who usually diagnose the disease to be caused by evil spirits.
Water Disposal
Majority of the households who cannot afford plumbing installation in their homes, availed of any
possible means of convenience for their waste disposal.

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Some excreted in any waterways:
1. rivers
2. seashores
3. creeks
Some excreted in any secluded place:
1. trees
2. bushes
Early attempts of promoting plumbing and sanitary waste disposals were accepted by few who could
afford. In the rural areas however, constructed toilets were merely excavated pits covered with coconut
trunks, bamboos or any suitable material provided with a slot where the user shoots his excretion. And
some others were constructed along riverside where one would see his excretion splashing on the
water below.
Those early sewage disposal practices were not only harmful to human health, but also to the
environment particularly to the more populated areas. Indeed, it did not take long for a burgeoning
urban population, to realize the importance of sanitation facilities in the form of an efficient water supply
and sewage disposal system. In the rural areas however, it took another decade and more government
prodding to encourage the population to adopt the sanitary water supply and waste disposal system.
Due to the eminent outbreak of epidemics brought about by the worsening unsanitary condition
prevailing, certain sector of the society and the government, introduced programs to address the
situation. Massive education on proper sanitation was initiated. Water supply systems were constructed
in some urban areas. Model toilets were built. Low cost concrete water seal closet was introduced
to the rural residents backed up by local ordinances, requiring every residence to have a sanitary
comfort room with proper sewage disposal system known as Septic Tank.
D. Objectives of Plumbing
Plumbing has 2 main objectives:
1. To supply water to different parts of the building
2. To remove and discharge human wastes and other substances out of building into the public
sewer or septic tank.
Conditions for an effective water supply in building:
1. To provide sufficient amount of water to supply each fixture.
2. To prevent back flow of used water into the water supply system
The drainage system should accomplish the following:
1. Fast removal of the waste with a minimum probability of leakage and stoppage of drains.
2. To prevent the entry of house vermin and obnoxious gases into the house from the piping
system.
Mandatory requirements for a drainage system
All plumbing design and installations are governed by a set of rules and limitations prescribed by the
National Plumbing Code, which provides that:
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 “All drainage system must conform with a set of requirements enumerated as follows”:
1. That, all pipe joints must be well fitted and tightly connected with each other to prevent leakage
of gas and liquid.
2. That, the drainage pipe should be graded or inclined properly for a downward gravity flow of
water towards the main sewer line or to the septic tank.
3. That, the drainage pipe should be provided with adequate cleanout, accessible for repair in
case of stoppage.
4. The drainage system must be provided with ventilation pipe that will convey gases to the
atmosphere where it can do no harm to human health.
5. That, except for water closet, each fixture shall be provided with suitable trap that will prevent
back flow of gases.
6. That, the drainage system must be vented, to avoid siphonage or back flow of the water seal.

E. Plumbing Design Unlimited

The design and layout of a plumbing system is governed be set of rules promulgated by the National
Plumbing Code. The Code however, does not impose a fixed standard design of the piping layout, more
particularly, the placing and location of the various plumbing fixtures. And to think of the unlimited
design of these fixtures, the different types of plumbing system design go with it.
While we subscribed to the health and safety requirements prescribed by the National Plumbing Code,
unlimited designs are to be expected from various designers. The routing of the entire plumbing, the
location of the outlets and cleanouts plus other related installations are subject to considerable freedom
of choice and design.
F. The Drainage System
To anyone, the word plumbing connotes fixtures and piping installations that will supply water and
dispose waste in various forms. Waste is classified in 2 types:
1. Solid Waste – discharged by water closet
2. Liquid Waste – coming from various fixtures
These types of wastes are also conveyed and disposed of by 2 types of drainage piping:
1. Soil Pipe – conveys waste coming from water closet. However, it can also convey waste from
other fixtures.
2. Waste Pipe – conveys waste from various fixtures other than water closet
The drainage installation is sometimes referred to as DWV which means:
D – drainage of solid waste
W – waste coming from various fixtures other than water closet
V – ventilation of the piping system
G. Modern Plumbing Systems
Modern cities have sophisticated water delivery and wastewater treatment systems.

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In buildings, the plumbing system performs two primary functions:

1. water supply
2. waste disposal
A complete plumbing arrangement consists of:

1. Water Supply System

- consists of the piping and fittings that supply hot and cold water from the building water supply
to the fixtures, such as lavatories, bathtubs, water closets, dishwashers, clothes washers,
and sinks.

2. Sanitary Drainage System

- consists of the piping and fittings required to take that water supplied to the fixtures out of
the building and into the sewer line or disposal field. This system is typically referred to as a
sanitary drainage system or drain, waste and vent (DWV) system.

3. Wastewater Treatment System

- Because of environmental concerns, wastewater treatment is also an important component
of waste disposal from building plumbing systems. Although most buildings rely upon district
or community water treatment plants to dispose of their sewage, some buildings and facilities
operate their own operations. These are generally known as septic or on-site sewage
treatment (OSST) systems.

Plumbing System

- is a network of pipes, fittings, and valves that carry and control flow of supply water and
wastewater to and from points of use known as fixtures.

❖ Fixtures
- are components, receptacles, or pieces of equipment that use water and dispose of
wastewater at the point of water use.

❖ Piping
- is a series of hollow channels that carry water to and wastewater from plumbing fixtures.

❖ Fittings
- are used to connect lengths of pipe in the piping network.

❖ Valves
- are used to regulate or control flow of water.

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FIGURE 1: DWV WITH COLD AND HOT WATER SUPPLY

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FIGURE 2: DWV CONNECTED TO THE MAIN SEWER LINE

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 A. DEFINITION OF TERMS
1. Air Gap – (in a water supply system) the unobstructed vertical distance through the free atmosphere
between the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture, or other
device and the flood level rim of the receptacle.
2. Back Flow – the flow of water, or other liquid mixture or substances into the distributing pipes of a potable
supply of water from any source, other than its intended source.
3. Back Siphonage – the back flow of used contaminated or polluted water from a plumbing fixture or
vessel into a water supply pipe due to a negative pressure in such a pipe.
4. Battery of Fixture – any group of 2 or more similar adjacent fixture which discharges into a common
horizontal waste pipe or soil branch.
5. Bib – synonymous with faucet, cock, tap, plug, etc. The word faucet is preferred.
6. Blind Flange – a flange that closes the end of a pipe. There is no opening for the passage of water.
7. Blow Off – a controlled outlet on a pipeline used to discharge water.
8. Branch – any part of piping system other than the main riser or stack.’
9. Branch Interval – the length of a soil or waste stack corresponding in general to a storey height, but in
no case less than 2.40 meters within which the horizontal branches from one floor or storey of a building
are connected to the stack.
10. Branch Vent – a vent connecting one or more individual vents with a vent stack or stack vent.
11. Calking – plugging an opening with oakum, lead or other materials, that are pounded into the place or
opening.
12. Circuit Vent – a branch vent that serves 2 or more traps, and extends from the front of the last fixture
connection of a horizontal branch to the vent stack.
13. Continuous Vent – a vertical vent that is a continuation of the drain to which the vent connects.
14. Combination Fixtures – a fixture combining one sink and tray or a 2 or 3 compartment sink or tray in
one vent.
15. Combination Waste and Vent System – a specially designed system of waste piping embodying the
horizontal wet venting of one or more sinks or floor drains by means of a common waste and vent pipe
adequately sized to provide free movement of air above the flow line of the drain.
16. Common Vent – a drain from 2 or 3 fixtures connected to a single trap. It is also called a dual vent.
17. Cross Connection – any physical connection between 2 otherwise separate piping system, one contains
potable water, and the other from an unknown or questionable safety, whereby, water may flow from one
system to the other direction of flow depending on the pressure differential between the two systems.
18. Dead End – the extended portion of a pipe that is closed at one end permitting the stagnation of water
or air therein.
19. Developed Length – the length along the center of the pipe and fitting.
20. Diameter – (of a pipe or tube) nominal internal diameter (ID) of such pipe, except brass and copper tube
where the term refers to the outside diameter (OD) of the pipe.
21. Drainage System – includes all piping within the public or private premises that conveys sewage,
rainwater or other liquid waste, to a legal point of disposal. It does not include the mains of public sewer
system, private or public sewerage treatment or disposal plant.
22. Dry Vent – a vent that does not carry water or water-borne wastes.
23. Effective Opening – the minimum cross-sectional area at the point of water supply discharge, measure
or expressed in terms of diameter of a circle. If the opening is not a circle, the diameter of a circle that is
equivalent to the cross-sectional area is used. (This is applicable to air gap)
24. Existing Work – shall apply to that portion of a plumbing system that has been installed and approved
prior to the contemplated addition, alteration or correction.
25. Fixture Branch – a pipe connecting several fixtures.
26. Fixture Drain – the drain from the trap of a fixture to the junction of that drain with any other drain pipe.
27. Fixture Supply – a water supply pipe connecting the fixture with the fixture branch.

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28. Fixture Units – a quantity in terms of which the load producing effects on the plumbing system of different
kinds of plumbing fixtures are expressed on some arbitrary chosen scale.
29. Fixture Unit Flow Rate – the total discharge flow in gallons per minute (gpm) of a simple fixture divide
by 7.5 gallons that provides the flow rate of that particular plumbing fixture as a unit of flow. Fixtures are
rated as multiple of this unit of flow.
30. Flood Level – a device located inside the tank for the purpose of maintaining water level for effective
flushing of the water closet.
31. Ferrule – a metallic sleeve called or otherwise joined to an opening in pipe into which a plug is screwed
that can be removed for the purpose of cleaning or examining the interior of the pipe.
32. Flush Valve – a device located at the bottom of the tank for flushing water closets and similar fixtures.
33. Flushometer Valve – a device which discharges a predetermined quantity of water to the fixture for
flushing purposes activated by direct water pressure.
34. Grade – the slope or fall of pipe in reference to a fraction of an inch per foot length of pipe.
35. Group Vent – a branch vent that performs its function for 2 or more traps.
36. Horizontal Pipe – any pipe or fitting which makes an angle of more than 45° with the vertical.
37. Invert – the lowest point of the inside of any pipe or conduit that is not vertical.
38. Liquid Waste – the discharge from any fixture, appliance or appurtenance in connection with a plumbing
system which does not receive fecal matter.
39. Local Vent Pipe – a pipe on the fixture side of the trap through which vapor or foul air is removed from
a room or fixture.
40. Looped Vent – the same as circuit vent except that it loops back and connects with a stack vent instead
of a vent stack.
41. Lateral – (in plumbing) a secondary pipe. (in sewage) a common sewer to which no other common sewer
is tributary. It receives sewage only from the building sewer.
42. Main – (of any system of continuous piping) the principal artery of the system to which branches may be
connected.
43. Main Sewer – a sewer line or system directly controlled by public authority.
44. Main Vent – the principal artery of the venting system to which vent branches may be connected.
45. Plumbing Fixtures – installed receptacles, devices or appliances which are supplied with water, or which
receives or discharges liquid or liquid-borne waste, with or without discharge into drainage system which
maybe directly or indirectly connected.
46. Plumbing System – includes the water distribution pipes; plumbing fixtures and traps; soil, waste and
vent pipes; house drain and house sewers including their respective connections, devices and
appurtenances within the property line of premises; and water treating or water using equipment.
47. Relief Vent – its primary function is to provide circulation of air between drainage and vent systems.
48. Re-Vent Pipe – (sometimes called individual vent) part of the vent pipeline which connects directly with
an individual waste or group of wastes, underneath or back of the fixture, and extend either to the main
or branch vent pipe.
49. Riser – a water supply pipe which extends vertically one full storey or more to convey water to branches
or fixtures.
50. Rough-In – the installation of all parts of the plumbing system which can be completed prior to the
installation of fixtures. This includes drainage, water supply, vent piping and the necessary fixture
supports.
51. Return Bend – an open return bend usually with inside threads, but applied also to 180° bend in pipe.
52. Public Sewer – a common sewer directly controlled by public authorities where all abutters have equal
rights of connection.
53. Sanitary Sewage – the sewage containing human excrement liquid household waste. It is also called
domestic waste.
54. Sanitary Sewer – a sewer intended to receive sanitary sewage with or without industrial wastes and
without the admixture of surface water, storm water or drainage.
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 55. Secondary Branch – any branch in a building drain other than the primary branch.
56. Sewerage of Sewage Work – a comprehensive term including all construction or collection,
transportation, pumping, treatment and final disposition of sewage.
57. Siamese Connection – a Y connection used on fire lines so that 2 lines of hose maybe connected to a
hydrant or to the same nozzle.
58. Standpipe – a vertical pipe usually used for the storage of water, frequently under pressure.
59. Side Vent – a vent connecting to the drain pipe through a fitting at an angle not greater than 45° or to
the vertical.
60. Soil Pipe – any pipe that conveys the discharge of water closets or fixture having similar functions, with
or without the discharge from other fixtures, to the building drains (house drain) or building sewer (house
sewer).
61. Stack – the vertical main of a system of soil, waste or vent pipe.
62. Stack Group – a term applied to the location of fixtures in relation to the stack so that by means of proper
fittings, vents may be reduced to a minimum.
63. Stack Vent – the extension of a soil or waste stack above the highest horizontal drain connected to the
stack. It is sometimes called soil vent or waste vent.
64. Stack Venting – a method of venting fixture/s through the soil or waste stack.
65. Subsoil Drain – underground drain pipes that receive sub-surface or seepage water only and convey it
to a place of disposal.
66. Sump – a pit or receptacle at a low point to which the liquid wastes are drained.
67. Trap – a fitting or device so designed as to provide when properly vented a liquid seal that will prevent
the back passage of air without materially affecting the flow of sewage through it.
68. Trap Seal – the maximum vertical depth of liquid that trap will retain, measured between the crown weir
and top of the dip of the trap.
69. Vent Stack – a vertical pipe installed primarily for the purpose of providing circulation of air to different
parts of the drainage system.
70. Vent System – pipe/s installed to provide a flow or circulation of air within the plumbing system to protect
trap seals siphoning and back pressure.
71. Vertical Pipe – a pipe installed in a vertical position or at an angle of not more than 45° with the vertical.
72. Waste Pipe – a pipe that conveys liquid waste from fixture that is free of fecal matter.
73. Water Distributing Pipe – (in a building or premises) a pipe that conveys water from the water service
pipe to the plumbing fixtures and other water outlets.
74. Water Service Pipe – the pipe from the water main or other source of water supply to the building served.
75. Water Supply System – (of a building or premises) consists of the water service pipe, the water
distributing pipes and the necessary connecting pipes, fitting, controlling valves and all appurtenance in
or adjacent to the building or premises.
76. Wet Vent – a vent that receives the discharge from wastes other than water closet.

B. WATER: THE SUBSTANCE

Water

- is the name given to the liquid compound H2O. A molecule of water is composed of one oxygen atom
and two hydrogen atoms. In a pure state, it is tasteless and odorless. The physical properties of water
are provided in Tables 12.1 and 12.2.
Under standard atmospheric pressure (14.696 psi, 101.04 kPa):

Boiling point temperature of water = 212°F (100°C)

Freezing point of water = 32°F (0°C)

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❖ The temperature at which water boils decreases with lower atmospheric or system pressure and
increases at higher pressures. Thus, the temperature at which water boils decreases with elevation
increase. For example, at standard atmospheric conditions at an elevation of 5000 ft (1524 m) above sea
level, water boils at 202.4°F (94.7°C). It boils at 193.2°F (89.6°C) at 10 000 ft (3048 m) above sea level.

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Fundamental Units
Several fundamental units describe the properties and behavior of water in building plumbing systems.
Customary and SI unit conversions for water based on weight, pressure, flow, and volume are provided in Table
12.3.

1. Specific Weight (Density) (w)

- is weight per unit volume.

❖ Water density varies with temperature; it is most dense at 39°F (4°C). Below this temperature, crystals
begin to form, increasing its volume and therefore decreasing its density. Water attains a specific weight
of 62.42 lb/ft3 (1.00 kg/L) at a temperature of 39°F (4°C). Above and below 39°F, water is less dense; for
example, the specific weight of water at 80°F (27°C) is 62.2 lb/ft3 (0.996 kg/L). A specific weight of 62.4
lb/ft3 (1.00 kg/L) is commonly used for liquid water in engineering computations.

2. Specific Gravity (s.g.)

- (fluid or solid) is the ratio of the specific weight of the fluid or solid to the specific weight of water at a
temperature of 39°F (4°C), the temperature at which water is most dense (62.42 lb/ft 3 or 1.00 kg/L).

❖ It is a comparison of its weight with the weight of an equal volume of water. Materials with a specific
gravity less than 1.0 are less dense than water (e.g., oil) and will float on pure water; substances with a
specific gravity more than 1.0 are denser than water and will sink. The specific gravity of water is assumed
to be 1.0 at common plumbing system temperatures.

3. Volume (V)
- is the amount of space occupied by a substance.

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❖ Water volume is typically expressed in cubic inches (in 3) or cubic feet (ft3) in the customary system, and
in cubic meters (m3) or liters (L) in the SI system. In plumbing system design, volume is commonly
expressed in gallons (g or gal).
1 ft3 = 7.48 gal
1 gal = 3.8 L

4. Volumetric Flow Rate (Q)

- frequently called the flow rate, is the volume of a substance that passes a point in a system per unit
of time.

❖ Flow rate is usually expressed in liters per second (L/s), liters per minute (L/min), or cubic meters per
second (m3/s) in the SI system. In the customary system, volumetric flow rate is expressed in cubic feet
per second (cfs or ft3/s), cubic feet per minute (cfm or ft 3/min), gal per second (gps or g/s), and gal per
minute (gpm or g/min).

Volumetric flow rate (Q) may be determined with volume (V) and time (t):
Q = V/t

5. Velocity
- is the rate of linear motion of a substance in one direction.

❖ The magnitude of velocity, known as speed, is usually expressed in terms of distance covered per unit
of time. In the customary system of weights and measures, velocity is expressed in inches per second
(in/s) or feet per second (ft/s). In the international system of measure (the SI system), velocity is
expressed in meters per second (m/s).

In a fluidic system such as a plumbing system, water velocity is expressed as an average velocity
because water molecules each have different speeds and directions of travel; that is, water molecules
flowing in the center of a pipe tend to travel faster than water molecules at or near the inner wall of the
pipe.

❖ Average velocity (v)

- Average velocity of a fluid such as water flowing through a pipe may be found by the following
equations based upon average volumetric flow rate (Q) and cross-sectional area (A) or inside
diameter (Di). Units must be consistent in these equations (e.g., volume, area, and diameter must be
expressed in units of in, ft, m, and so on).
𝑄 𝑄
𝑣= = 𝜋
𝐴 2
4 𝐷𝑖

❖ The following equation, in customary units, is useful in plumbing system design. It may be used to find
the average velocity (v) of a fluid flowing through a pipe, in ft/s, based on the volumetric flow rate (Q), in
gpm, and an inside diameter (Di) of the pipe, in inches:
𝑄
𝑣 = 0.409
𝐷𝑖 2

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 ❖ The following equation, in SI (metric) units, may be used to find the average velocity (v) of a fluid flowing
through a pipe, in m/s, based on the volumetric flow rate (Q), in L/min, and an inside diameter (Di) of the
pipe, in mm:
𝑄
𝑣 = 21.22 2
𝐷𝑖

6. Pressure (P)
- is the force per unit area exerted by liquid or gas on a surface such as the sidewall of a container or
pipe.

❖ In the customary system of measure, pressure is expressed in pounds per square inch (lb/in2 or psi) or
pounds per square foot (lb/ft 2 or psf). In the international system (SI), pressure is expressed in Newton
per square meter or the Pascal (N/m 2 or Pa). Although units of lb/in 2 are dimensionally correct, the
acronym “psi” will be used for pounds per square inch of gauge pressure because it is universally
accepted in the plumbing industry. The acronym “psia” will be used for absolute pressure.

❖ Standard atmospheric pressure (Ps)

- is the typical barometric pressure of air at sea level and 70°F (21°C). It is equal to 14.696 psia (101
325 Pa). Atmospheric pressure varies with weather conditions and elevation. In Denver, Colorado,
atmospheric pressure is about 11.8 psia because Denver is about a mile above sea level; it is above
about 20% of the earth’s atmosphere.

❖ Gauge pressure (Pg)

- is the pressure of a fluid (gas or liquid) excluding pressure exerted by the atmosphere. Pressure can
be expressed in terms of absolute and gauge pressure.

❖ Absolute pressure (Pa)

- is the pressure of a fluid (gas or liquid) including pressure exerted by the atmosphere:
Pa = Pg + Ps

A gauge is frequently used to record the pressure difference between the system and the atmospheric pressure.
Normally, if pressure in a system is below atmospheric pressure, it is called vacuum pressure or a suction
pressure. It is expressed as a negative gauge pressure.

Saturation Vapor Pressure

- is the pressure that water vapor molecules exert when the air is fully saturated at a given temperature.
Saturation vapor pressure is directly proportional to the temperature: it increases with rising
temperature and falls with decreasing temperature.
In plumbing systems there are three additional classifications of pressure:

1. Static pressure
- is the pressure that exists without any flow. It is the pressure available at a location in the system.
2. Residual pressure
- is the pressure available at a fixture or outlet during a period of maximum demand. It is the pressure
that exists after pressure losses from friction from water flow, elevation change, and other pressure
losses in the system are subtracted.

CVIL 1083 – ENGINEERING UTILITIES 2 | 9

 3. Discharge pressure
- is the pressure of the water at the point of discharge, such as at the mouth of a showerhead, faucet,
or hose bibb.
Partial Pressure

The constituent gases that make up a mixture of gases such as air each exert a partial pressure that contributes
to the total pressure exerted by the gas mixture. For example, atmospheric air consists of about 75% nitrogen,
by weight, so 75% of the total pressure exerted by atmospheric air is from the nitrogen constituent. Thus, under
standard conditions (14.696 psia), the partial pressure of nitrogen is 11 psia, 75% of the total pressure. The
partial pressure of a constituent gas in a mixture of gases equals the pressure it would exert if it occupied the
same volume alone at the same temperature.

Water Vapor Pressure

- is the pressure that the water vapor molecules alone exert in air. It is based on the amount of water
vapor that exists in the air. Like all constituent gases in air, water vapor exerts a pressure, which is
known as vapor pressure. Water vapor pressure is the contribution of water vapor to the total pressure
exerted by a gas. In buildings, this gas is atmospheric air.
A difference in pressure in a system is required for a fluid to flow; for example, a pump increases the pressure
of the liquid passing through it, thereby causing flow. Flow will always be from a high-pressure region to a low-
pressure region. Pressure difference is the driving force behind water flow. An increase in pressure difference
will increase flow.

EXAMPLES:

1. Raw sewage is found to weigh 60.5 lb/ft3. Determine its specific gravity.
SOLUTION:
s.g. = wraw sewage/wwater = 60.5 lb/ft3/62.42 lb/ft3 = 0.969

2.
a. Determine the volumetric flow rate, in gpm, for water flowing out of a faucet based on 2 gal in 23 s.
b. Determine the volumetric flow rate, in L/s, for water flowing out of a faucet based on 6 L in 8 s.
SOLUTION:
V
a. Q = t
2 gal
Q= 1 min
23 s x
60 s
Q = 5.22 gpm
V
b. Q = t
6L
Q= 1 min
8sx
60 s
Q = 45 L/s

❖ A faucet supplying water at a volumetric flow rate of 5 gpm will fill a 5 gal bucket in exactly 1 min or a 1
gal bucket in 12.5 s (one-fifth of a minute). In plumbing system design, volumetric flow rate is found by
multiplying the area of the inside diameter of the pipe carrying the water by the average velocity of the
flowing water.

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3. Determine the average velocity for water flow in a pipe under the following conditions:
a. A 3⁄4 in diameter, Type L copper tube (0.875 in outside diameter and 0.785 in inside diameter) carrying
water at a volumetric flow rate of 10 gpm.
b. A 2 in diameter, Schedule 40 chlorinated polyvinyl chloride (CPVC) pipe (2.375 in outside diameter and
2.047 in inside diameter) carrying cold water at a volumetric flow rate of 40 gpm.
SOLUTION:
𝑄
a. 𝑣 = 0.409 𝐷𝑖 2

10
𝑣 = 0.409
(0.785)2

v = 6.64 ft/s
𝑄
b. 𝑣 = 0.409 𝐷𝑖 2

40
𝑣 = 0.409
(2.047)2

v = 3.90 ft/s

4. Determine the average velocity for water flow in a 20 mm diameter copper tube (21.4 mm outside
diameter and 19.9 mm inside diameter) carrying water at a volumetric flow rate of 40 L/min.
SOLUTION:
𝑄
𝑣 = 21.22 2
𝐷𝑖
40
𝑣 = 21.22
(19.9)2
v = 2.14 m/s

5.
a. At sea level, atmospheric pressure is 14.7 psia (101 325 Pa). A pressure gauge placed at the bottom
of an 8 ft (2.45 m) deep tank filled with water measures a water pressure at the tank bottom of 3.5 psi
(24 130 Pa). Determine the absolute and gauge pressure.
b. At sea level, atmospheric pressure is 14.7 psia (101 325 Pa). A bicycle tire (at sea level) is inflated
to 50 psi (344 737 Pa). Determine the gauge and absolute pressures in the inflated tire.
c. In Denver, atmospheric pressure is about 11.8 psi (81 358 Pa). A bicycle tire (in Denver) is inflated
to 50 psi (344 737 Pa). Determine the gauge and absolute pressures in the inflated tire.
SOLUTION:
a. Gauge pressure at the bottom of the tank:
Pg = 3.5 psi (24 130 Pa)
Absolute pressure at the bottom of the tank:
Pa = Pg + Ps
Pa = 3.5 + 14.7
Pa = 18.2 psia
or
Pa = 24 130 + 101 325
Pa = 125 455 Pa

CVIL 1083 – ENGINEERING UTILITIES 2 | 11

b. Gauge pressure of the inflated tire:
Pg = 50 psi (344 737 Pa)
Absolute pressure of the inflated tire:
Pa = Pg + Ps
Pa = 50 + 14.7
Pa = 64.7 psia
Or
Pa = 344 737 + 101 325
Pa = 446 062 Pa

c. Gauge pressure of the inflated tire:

Pg = 50 psi (344 737 Pa)
Absolute pressure of the inflated tire:
Pa = Pg + Ps
Pa = 50 + 11.8
Pa = 61.8 psia
Or
Pa = 344 737 + 81 358
Pa = 426 095 Pa

CVIL 1083 – ENGINEERING UTILITIES 2 | 12

 PLUMBING MATERIALS
Introduction

Most popular and commonly used kind of materials available for plumbing installation:
1. Cast iron soil pipe
2. Acid resistant cast iron pipe
3. Asbestos pipe
4. Bituminous fiber sewer pipe
5. Vitrified clay pipe
6. Lead pipe
7. Galvanized steel pipe
8. Galvanized wrought iron pipe
9. Brass pipe
10. Copper pipe
11. Plastic synthetic pipe
12. Stainless steel pipe

The choice of the kind of pipe to be installed depends upon the following considerations:
1. Quality and durability
2. Resistance to external and internal contact with foreign matters
3. Resistance to acid waste and other chemical elements that will pass into it
4. Cost of materials and labor

1. CAST IRON PIPE

PROS CONS
Most popular and generally specified material for Affected by corrosion caused by the action of
drainage system in buildings for the past several carbon dioxide, sulfur oxide and methane gas
decades forming solutions of carbonic acid and sulfuric acid.
These acids attack the metallic material causing a
slow chemical reaction or oxidation to take place
forming ferrous oxide called rust.
Commonly used in gravity building and storm Cast iron pipes and fittings are limited to gravity
drain/sewer systems pressure systems.
Durable, conveniently installed and answer to the Constant vibrations which causes water leak of the
most plumbing needs of all types of buildings less pipe joints for buildings taller than 25 storey
than 25 storey high

2 Types of Cast Iron Pipe:

a. SV (Service) Type
- generally used for above-grade installations and building installation
b. XH (Extra Heavy) Type
- used for applications below grade and underground installation

4 Varieties of Cast Iron Pipe:

a. Standard Pipe
b. Single Hub Pipe
c. Double Hub Pipe
d. Hubless Pipe

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 2. ACID RESISTANT CAST IRON PIPE
- made from alloy of cast iron and silicon
PROS CONS
Widely used in chemical laboratories, industries and Brittle in character and requires stronger support for
other installations where acid wastes are being each pipe installed horizontally to prevent sagging
discharged of joints

3. ASBESTOS PIPE
- made of asbestos fibers and Portland cement.

PROS
Its thickness is twice as that of standard cast iron
pipe.
Could be used in soil, waste, ventilation and
downspout
Remarkably superior for embedment in concrete
structure for having the same material properties

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 JOINTS
- All joints are suitably grouted and firmly packed with oakum or old hemp rope. They are soaked in
tar to be watertight and well secured with pure lead not less than 25 mm deep, well calked, or filled
with cement mortar. For chimney joints, mineral lead is replaced with cement mortar.

4. BITUMINOUS FIBER SEWER PIPE

PROS CONS
Cheapest among the sewer pipes Excessive hot water or chemical flow may soften or
Sometimes recommended for house sewer and for damage the pipe.
septic tank installation
Light in weight, slightly flexible which could take
slight movement w/o danger of cracking or pulling
out from its joint

CVIL 1083 – ENGINEERING UTILITIES 2 | 9

 5. VITRIFIED CLAY PIPE
- one of the oldest materials used for sewer lines
- made out from clay, cast into length of 75 cm treated with glazing compound. The pipe is heated in
a large kiln under a temperature of 1370°C, making it impervious to moisture.

PROS CONS
Highly resistant to most acid wastes Brittle physical property. Hence, it should not be laid
Durable material for underground installations like on unstable ground base.
public sewer, house sewer or storm drain.

CVIL 1083 – ENGINEERING UTILITIES 2 | 10

 6. LEAD PIPE
- also one of the oldest plumbing materials used by the Egyptians, the Greeks and the Roman builders
as soil and waste pipe.

PROS CONS
Highly resistant to acid and is suitable for Never used to convey water for human consumption
underground installation because lead is poisonous and injurious to human
health

7. GALVANIZED STEEL PIPE

- made out from mild steel, drawn through a die and welded, cast into 6 m long.

CONS
Easily corroded by alkaline and acid water. The
carbonic acid in water attack the zinc coating and
ultimately the steel itself.
It is subject to deposits of salt and lime that gradually
accumulate and finally choke the flow of water.
It deteriorates faster when used as hot water supply
line.

8. GALVANIZED WROUGHT IRON PIPE

PROS
Better in quality than the steel pipe for plumbing
installation.
Test showed that it is more resistant to acid waste
than the steel pipe
CVIL 1083 – ENGINEERING UTILITIES 2 | 11
 9. BRASS PIPE
- made of an alloy of zinc and copper mixed at 15% and 85% proportion respectively. Brass pipe fittings
are of the recessed type similar in design with galvanized steel pipe.

PROS CONS
Superior material for waste and water supply One of the most expensive types of pipes
installations because of its smooth interior surface
and high resistance to acid

10. COPPER PIPE

PROS
Durable and extremely corrosive resistant material
Easy to install compared with other types of pipe

3 Types of Copper Pipe:

a. K Type
- heaviest; has the thickest walls
- suitable for underground installation
- preferred for pressure applications
b. L Type
- lighter than the K type
- available in both rigid and flexible form
- commonly used in residential water supply line and for radiant heating installations
- also preferred for pressure applications
c. M Type
- thinnest
- available only in rigid form
- specially designed for small water supply lines and for radiant heating installations
- used for low and no-pressure applications

Comparisons to Steel Pipe:

a. Copper pipe costs little more than the steel pipe but its fittings cost lesser than that of the steel pipe.
b. Because of its very smooth interior surface, one size smaller pipe could be used instead, w/o substantial
reduction of liquid flow.
Example: Where a 25 mm (1”) diameter steel pipe is required, a 20 mm (3/4”) diameter copper pipe is
equally sufficient.
Special Features of Copper Pipe:
a. It could be used as drain and vent pipe.
b. It could be used as cold water supply line.
c. It is remarkably excellent material for hot water lines.
d. It can replace rusted or choked-up sections of galvanized steel pipe.
e. No special tools required to install copper pipe nor threading is necessary.
f. It is bent easily. A flexible vertical line can offset existing structure. Underground lines can be rerouted
around an obstruction.
g. Measuring is less critical.
h. It needs fewer joints and fittings.
i. It comes in longer length.
j. It may be used one size smaller than a steel pipe.

Note: In installing hot water line, the use of bigger pipe should be avoided because heat loss on larger pipe is
higher than on a smaller one.

CVIL 1083 – ENGINEERING UTILITIES 2 | 12

 11. PLASTIC SYNTHETIC PIPE
- a new concept in the field of plumbing. It was introduced in the Philippines at the early 70’s, although
it was developed in Germany in the mid-year of 1935.
- has gained widespread acceptance after it has in many ways proven itself to be superior as sewer
and cold water pipe line.

Some codes however are still apprehensive in approving its use. According to Dick Demske:
“Many codes have not been updated since the days when plastic was still in the test tube stage, and
therefore do not make any mention of the type of plastic piping that are in widespread use today…
Building authorities have a reputation for hard headedness and it is not unknown for them to require the
tearing down of an installation that does not conform to their codes.”

Types of Plastic Synthetic Pipes:

a. Rigid Type
b. Flexible Type

CVIL 1083 – ENGINEERING UTILITIES 2 | 13

The Rigid Types:
a. Polyvinyl Chloride (PVC)
b. Chlorinated Polyvinyl Chloride (CPVC)
c. Unplasticized Polyvinyl Chloride (uPVC)
d. Acrylonitrile Butadiene Styrene (ABS)
e. Polypropylene (PP)
f. Styrene Rubber Plastic (SR)

The Flexible Types:

a. Polyethylene (PE)
b. Polybutylene (PB) – manufactured w/ special length up to 150 m long in coil form.

PE & PB - in coil form available at 30 m long

The plastic pipes being used for hot water lines recently:
a. CPVC
b. PP
c. PVDC (Polyvinyl Dichloride)

It seems to be all right but whether it could withstand hot water at 180°F or higher temperature, plus the
pressure of hot water for years w/o any amount of substantial collapse or damage itself, is still a matter
of facts to be proven. Thus, extensive research is still going on to develop plastic pipes suitable for hot
water.

Advantages of Plastic Pipe:

a. It is more resistant to rust and corrosion.
b. Water conveyed by plastic pipe has no pipe tastes.
c. The extreme smooth interior surface prevents the buildup of scale, rust and foreign material that often
impedes flow through metallic pipes.
d. There is no turbulence of water and therefore, has a minimum resistance to flow.
e. PVC pipe and fittings weigh about 1/5 of the metal pipe. They are easily and quickly installed through
solvent cementing.
f. Plastic pipes are cast in longer length and easy to cut as well as to install.
g. The Polyethylene (PE) pipe is flexible material that weighs about 1/8 as much as the steel pipe.
For example: A 100 m long 25 mm diameter coil plastic pipe could be easily carried by one individual
compared with metal pipes having the same length and diameter which could be hardly carried by 5
persons.
h. PVC pipe can be connected to existing metal pipe using a threaded adapter.
i. PVC is virtually acid proof to any chemical used in recommended strengths around the home.
j. No special tools are needed for installing PVC except a rule to measure and a saw to cut.
k. The best reason at all: You can do it yourself.

Certain chemicals such as methyl-ethyl-ketone (acetone), paint remover or paint brush cleaner should
not be poured in PVC or any other drainage pipe.

Selecting Your Plastic Pipes

Physical and mechanical properties of plastic pipes that manufacturers should publish for the users’ information:
1. Specific gravity
2. Hardness
3. Impact strength
4. Compression, shearing and tensile strength
5. Test results
6. Characteristic value of materials

CVIL 1083 – ENGINEERING UTILITIES 2 | 14

 Most of plastic pipes and fittings are produced from synthetic resins. The chemistry of plastic is
perplexing and the finished product could appear in a great variety of forms and colors. It is derived
from coal and petroleum products.

Celluloid - the first plastic material introduced about 100 years ago
1905 – Bakelite was developed.
Polyethylene (PE) – remarkably successful in water piping services for more than 50 years
1945 – Extensive researches on plastic products towards standardization of quality have started when various
plastic materials were introduced for plumbing use.
1972 – Approximately 4,500 state, country and city codes permitted the use of plastic pipe for all or a portion of
the plumbing system. The plumbing code that was promulgated by the Association of Plumbing Officials and
the Plumbing Contractors was called “Model Code”.

Support
PVC and CPVU installation must be supported when hanging from the ceiling, rafters or floor joists.

The Model Codes that approved the use of plastic pipe for plumbing systems are:
1. The National Standard Plumbing Code
2. Building Officials and Code Administrations International
3. National Associations of Plumbing, Heating, Cooling Contractors
4. Southern Standard Plumbing Code
5. Southern Building Code Congress
6. Uniform Standard Plumbing Code
7. International Association of Plumbing and Mechanical Officials

CVIL 1083 – ENGINEERING UTILITIES 2 | 15

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 FITTINGS AND VALVES

FITTINGS
- A variety of fittings must be used to connect pipe lengths and make all the pipe turns, branch lines,
couplings that join the straight runs, and stops at the end of the runs. Fittings for steel and wrought-
iron pipe are made of malleable iron and cast iron. The fittings for plastic, copper, and brass pipe are
made of the same materials as the pipe being connected.

1. ELBOWS
- (usually at 45°and 90°) angular fittings used to change the direction of a supply pipe. On a sanitary
drainage system, a sanitary bend makes a more gradual turn to prevent blockage.
2. TEES
- are used in a supply system when a line must branch off at a straight run. A reducing tee allows
different pipe sizes to be joined together in a supply system. Sanitary T and sanitary Y are tee-like
fittings used in sanitary drainage systems that make a more gradual turn to prevent blockage. A
sanitary Y can accept two or three branches before combining flow into one pipe.
3. COUPLINGS
- are used to join straight runs of pipe. A union joins straight runs of pipe but also allows the pipes to
be more easily disconnected when future piping revisions are expected or equipment needs to be
replaced. A reducer is a straight fitting used to decrease the diameter in a pipe in a water supply
system. An increaser is a straight fitting used to increase the diameter in a pipe in a sanitary drainage
system.
4. ADAPTERS
are used in a supply system where threaded pipe is being connected to copper or thermoplastic. Adapters
have one threaded end to accommodate threaded pipe.

JOINING PIPES AND FITTINGS

a. Pipes and fittings can be joined mechanically:
1. threaded joints
2. insert fittings with crimped connections or clamped connections
3. hub and spigot
4. flared (metal to metal) joints
b. Fire suppression sprinkler pipes are frequently joined using a grooved Victaulic fitting.
c. A compression fitting
- is a type of connection for tubing or pipe where a nut, and then a sleeve or ferrule, is placed over a
copper or plastic tube, and is compressed tightly around the tube as the nut is tightened, forming a
positive grip and seal without soldering.
d. Ways of Joining Metal Surfaces:
1. Soldering
- involves melting solder to a temperature below 840°F (449°C), usually in the range of 350°to 550°F
(177° to 288°C). Soldered joints are used when the service temperature does not exceed 205°F
(96°C).
2. Brazing
- involves melting the metal filler above 430°C (800°F), usually in the range of 1100°to 1500°F (593°to
816°C), but still below the melting temperature of the metals to be joined. Brazed joints offer greater
strength and should be used where operating temperatures are up to 400°F (204°C).

CVIL 1083 – ENGINEERING UTILITIES 2 | 1

 3. Welding
- typically involves joining two or more pieces of metal by the application of heat. Unlike soldering or
brazing, welding involves a partial melting of the surfaces of the metals to be joined. It offers the
greatest physical strength.
e. Plastic pipe materials
1. Solvent cementing
- involves coating the plastic surfaces with a prime coat and a solvent cement coat before they are
joined. The cement cures joining the surfaces in a manner similar to the cementing technique used
to attach the pieces of a plastic model airplane.
2. Fusion welding
- involves heating the surfaces until they melt, allowing them to be joined.

VALVES
- are used to control flow of the water throughout the system. Proper location of valves simplifies repairs
to the system, fixtures, or equipment being serviced. Valves also regulate flow to deliver the
appropriate quantity of water and reduce water consumption. In building plumbing systems, there are
usually valves at risers (vertical pipe serving the building), branches (horizontal pipe serving the
fixtures), and pipes to individual fixtures or equipment. The inner workings of most valves are
generally accessible for repairs.

1. GATE VALVE
- is a manual valve that has a wedge-shaped leaf that, when closed, seals tightly against two metal
seats that are set at slight angles. This type of valve is usually used where the flow of the water is left
either completely opened or closed for most of the time. Because the flow of water passes straight
through the valve, there is very little water pressure lost to friction. The gate valve is not used to
regulate flow of water. Instead, it is used to shut off the flow of water such as to fixtures and equipment
when repairs or replacement must be made.
2. GLOBE VALVE
- is a manual, compression-type valve, commonly used where there is occasional or periodic use, such
as lavatories (faucets) and hose connections (called hose bibbs). This type of valve regulates the
flow of water. Design of the globe valve is such that the water passing through is forced to make two
90° turns, which greatly increases the friction loss in this valve compared with that in a gate valve.
3. ANGLE VALVE
- is a manual valve similar in operation to the globe valve, utilizing the same principle of compressing
a washer against a metal seat to cut the flow of water. It is commonly used for outside hose bibbs.
The angle valve has a much higher friction loss than the gate valve and about half the friction loss of
the globe valve.
4. CHECK VALVE
- opens to allow the flow of water in the direction desired and prevents flow in the other direction.

Two Types of Check Valves:

a. SWING CHECK VALVE
- the pressure of the water forces the valve gate to swing open, but once the flow stops, gravity causes
the gate to fall closed, preventing a reversal of the flow. This type of valve must be mounted vertically
or horizontally to work properly.

CVIL 1083 – ENGINEERING UTILITIES 2 | 2

 b. SPRING CHECK VALVE
- is spring loaded. Water pressure forces the gate open much like the swing type, but when the flow
stops, a spring (not gravity) forces the gate closed. This enables the valve to be mounted in any
position and at any angle. This valve is used in such places as the water feed line to a boiler (heating
unit) where the water from the boiler might pollute the system if it backed up.

All valves are modifications of these fundamental types. Valves can also be categorized by their function.
There are several types of special valves that justify a description.

1. BALL VALVE
- is a manual valve that has a ball with a hole through it that is mounted between two seats. When the
ball hole is in line with the valve openings, full flow of water occurs. A 90° rotation of the ball causes
the valve to be fully closed. Ball valves are available in both on/off shutoff control and controlled-flow
designs. Controlled-flow ball valves are designed to regulate the flow of water.
2. METERED VALVES
- are designed to automatically discharge for a specific length of time and thus deliver a fixed quantity
of water before closing off flow. They operate by pushing down or against the valve handle. They are
used on lavatories in public restrooms such as in transportation terminals, restaurants, and
convention halls to ensure that water is shut off after a short period of time. A flushometer valve is a
metered valve that discharges a predetermined quantity of water to fixtures for flushing purposes
(e.g., water closets and urinals) and is closed by direct water pressures.
3. FLOW CONTROL VALVE
- automatically adjusts the rate of water flow to a predetermined flow rate as pressure in the system
varies. They can be used to limit flow at a fixture outlet thereby holding demand to a required
minimum.
4. THERMOSTATIC VALVE
- frequently called a tempering valve or mixing valve, is an automatic valve thermostatically blends hot
and cold water to desired temperatures and to prevent scalding.
5. TEMPERATURE-PRESSURE RELIEF (T/P) VALVES
- is a safety valve designed to limit pressure of a liquid vapor or gas. These valves are specified such
that the valve remains closed at normal operating pressures yet it is allowed to open to release
excessive pressure. They are commonly found as a safety feature on water heaters and boilers.

CVIL 1083 – ENGINEERING UTILITIES 2 | 3

6. PRESSURE-REDUCING VALVE
- is an adjustable valve designed to reduce pressure to a specific setting. These valves are commonly
used in building plumbing systems where street water pressure is excessive and needs to be reduced
before being sent to plumbing fixtures.
7. HOSE BIBB
- sometimes called a sill cock,is a valve designed to accept the threaded connection of a hose. A
freezeless hose bibb has a long body that when placed in an exterior wall, cuts off the water supply
near the interior wall surface. This allows water near the exterior wall surface to drain out when the
valve is closed to avoid freezing of water and valve damage in severe winter temperatures. Secured
hose bibbs require a specially designed knob to open the valve, which prevents use by the general
public.

8. FLUSHOMETER
- is a valve-like device designed to supply a fixed quantity of water for flushing toilets and urinals. When
operated, it automatically shuts off after a measured amount of water flow in order to conserve water.
It uses pressure from the water supply system rather than the force of gravity to discharge water.
9. SENSOR-OPERATED VALVES
- Modern urinals and water closets (toilets) use a sensor-operated valve that automatically flushes the
fixture when a user departs. The unit uses an infrared proximity sensor to detect a user approaching
the fixture, then waits until the user departs. A solenoid is used to actuate the flush. Typically, a batter
contained within the unit powers the sensor circuit.

Valves referred to as standard weight are designed to withstand pressures up to 125 psi (860 kPa).
High-pressure valves are also available. Most small valves have bronze bodies, while large valves (2 in
(50 mm) and larger) have iron bodies with noncorrosive moving parts and seats that must be replaced
periodically. They are available threaded or soldered to match the pipe or tubing used.

Valves must be installed in the appropriate direction of flow. An arrow cast in the body of the valve usually
indicates direction of flow. Some valves are better than others in regulating flow. Gate valves and ball
valves undergo excessive wear (from cavitation) when they are partially closed. Globe valves are
designed to more easily and effectively regulate flow.

CVIL 1083 – ENGINEERING UTILITIES 2 | 4

 PLUMBING FIXTURES
PLUMBING FIXTURE
- is an approved receptacle, device, or appliance that uses water and discharges wastewater such as
a water closet, urinal, faucet, shower, dishwasher, drinking fountain, hose connection, hose bibb,
water heater, water softener, underground sprinkler, hot tub, spa, and clothes washer. They must be
made of dense, durable, nonabsorbent materials with smooth, impermeable surfaces. Plumbing
fixtures are the only part of the plumbing system that the owners or occupants of the building will see
regularly, because most of the plumbing piping is concealed in walls and floors.

1. WATER CLOSET
- is a plumbing fixture that serves as an indoor receptacle and removal system for human waste.
Although this fixture is commonly called a toilet or commode, the building code specifically refers to
it as a water closet. Water closets are typically made of solid vitrified china cast with an integral (built-
in) trap. They are also available in stainless steel that is typically specified for high-vandalism
installations such as at highway rest stops, outdoor recreation areas, jails, and detention centers.
Water closets are available as single flush, flush tank, or flush valve fixtures.

ULTRA-LOW FLUSH (ULF) WATER CLOSETS

- average water consumption is 1.6 gal (6.0 L) per flush. Infrared and ultrasonic sensors can be built
into the flush valve to automatically flush and avoid nonflushing or double flushing.

a. FLUSH TANK WATER CLOSET

- has a water tank as part of the fixture. As the handle or button on a water closet is pushed, it lifts the
valve in the tank, releasing the water to flush out the bowl. Then, when the handle is released, the
valve drops and the tank fills through a tube attached to the bottom of the tank. This type of water
closet cannot be effectively flushed again until the tank is refilled. Foam lining can be installed in the
tank to minimize condensation on the outside of a toilet tank by insulating the cold water in the tank
from warm, humid air.

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b. FLUSH VALVE WATER CLOSETS
- have no tank to supply water. Instead, when the handle is pushed, the water to flush the bowl comes
directly from the water supply system at a high rate of flow. When used, it is important that the water
supply system be designed to supply the high flow required. Although most of the fixtures operate
effectively at a pressure of 20 psi (140 kPa), the manufacturer’s specifications should be confirmed
because higher pressure is often required.

a. FLOOR-MOUNTED FIXTURE
- is much less expensive in terms of initial cost, but the wall-mounted fixture allows easier and generally
more effective cleaning of the floor. It is acceptable for most residential applications.

b. WALL-MOUNTED FIXTURES
- are considered desirable for public use, and some codes even require their use in public places.
When wall-mounted fixtures are used in wood stud walls, a wider wall will be required than is
sometimes used with floor-mounted fixtures.

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 DUAL-FLUSH WATER CLOSET
- a technology first developed in the early 1980s, takes
water conservation one step further by using 1.6 gal (6.0
L) of water to flush solid waste but only 0.8 gal (3.0 L) to
flush liquid waste.

2. URINALS
- plumbing fixtures that are commonly used in public restrooms where it is desirable to reduce possible
contamination of the water closet seats. They are commonly available in vitreous china and
sometimes in enameled iron. They are also available in stainless steel for high-vandalism
installations. Floor and trough-type urinals are no longer allowed in new construction. Urinals are
available as flush tank or flush valve fixtures.

ULF URINALS - average water consumption is 1.0 gal (3.8 L) per flush. Special metal urinals with
straight drain lines limit average water consumption to 0.5 gal (1.9 L) per flush.

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WATERLESS URINAL
- a urinal that is specifically engineered to eliminate potable water consumption for urinal flushing. It
looks very much like a conventional urinal except the flush valve and piping that is normally positioned
above the fixture is omitted. Conventional urinals use about 3.5 (13 L) of water per flush and modern
water-saving urinals use about 0.5 to 1 gal (2 to 4 L) of water per flush. The chief benefit of waterless
urinals is that they do not use water. In office buildings and schools, waterless urinals can save up to
25 000 gal (100 000 L) of potable water per year per fixture, saving water and sewer costs and
reducing the burden on the municipal sewage and sewage treatment system.
- A waterless urinal fixture blocks odors and gasses by a means other than a traditional trap. Each
manufacturer constructs its waterless urinal fixture differently. The most popular types use a
removable cartridge that needs to be replaced on a regular maintenance schedule, or a liquid
sealant that must be regularly flushed and refilled periodically, usually by the housekeeping staff. With
most designs, urine flows by gravity off the smooth surface of the urinal into a trapped liquid with a
lighter- than-water specific density. The liquid floats, allowing the urine to flow through it to the drain.
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 The liquid remains and serves to trap the odor. One manufacturer recommends cartridge replacement
after an estimated 12 000 to 15 000 uses, which on average will be every 3 to 4 months depending
on usage.

3. BIDETS
- personal hygiene plumbing fixtures used for genital and perineal cleanliness. It is typically used after
using the water closet. Equipped with valves for hot and cold water, the inside walls of the bowl are
washed the same way as a standard toilet. The bidet is not designed or intended to carry away solid
human waste. It is installed alongside the water closet. The user sits on the fixture facing the wall
(and the water controls) and is cleansed by a rinsing spray. Bidets are available in vitreous china.
Some bidets have a warm air dryer that is used to blow dry the genital and perineal area after washing.

4. BATHTUBS
- plumbing fixtures used for bathing. They are available in enameled iron, cast iron, or fiberglass. Tubs
are available in a variety of sizes, the most common being 30 or 32 in (760 or 810 mm) wide; 12, 14,
or 16 in (300, 350 or 400 mm) high; and 4 to 6 ft (1.2 to 1.8 m) long. Whirlpool bathtubs are fitted
with jets that propel a current of warm water in a swirling motion.
- Enameled iron tubs are formed of steel that is clad with a porcelain enamel finish. They are generally
available in lengths of 41⁄2 and 5 ft (1.37 and 1.53 m); widths of 30 to 31 in (760 to 785 mm); and
typical depths of 15 to 151⁄2 in (375 to 387 mm).
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- The most commonly available length of fiberglass bathtubs is 5 ft (1.5 m), and it takes 34 to 36 in
(865 to 915 mm) of width to install. Generally, the fiberglass units are cast in a single piece. Many
include three walls (eliminating the need for a ceramic tile tub surround). It is this single-piece feature,
with no cracks or sharp corners to clean, which makes the fiberglass tub so popular with clients.
- Bathtub fittings may be installed on only one end of a tub, and the end at which they are placed
designates the tub. As you face the tub, if the fittings are placed on the left, it is called a left-handed
tub, and if placed on the right, it is right-handed.

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 5. SHOWERHEAD
- an overhead nozzle that sprays water down on the bather. Shower fittings may be placed over
bathtubs instead of having a separate shower space; this is commonly done in residences,
apartments, and motels. However, it is important that when a showerhead is used with a bathtub
fixture, the walls be constructed of an impervious material such as ceramic tile.

LOW-FLOW SHOWERHEADS
- average water consumption by a showerhead are that flow rates not exceed 2.5 gpm (9.5 L/min)
HANDSHOWER
- a showerhead attached to the end of a flexible hose, which the bather can hold during bathing or
showering.
SHOWER SURROUNDS
- cover the walls that enclose a shower stall. Special shower surrounds available include corner units
and gang head units.
SHOWER ENCLOSURE
- consists of glass panels, either framed or frameless, used to enclose bathtubs, shower modules,
shower receptors, and custom-tiled showering spaces.
RECEPTOR OR SHOWER PAN
- a shallow basin used to catch and contain water in the bottom of a showering space. They are
available in units of porcelain enameled steel, fiberglass, tile, terrazzo, marble, cement, or molded
compositions.
GANG HEAD SHOWER
- has multiple showerheads extending from the top of a post. It is commonly used in institutions,
schools, factories where workers must shower after work, and other locations where large numbers
of people must shower.

Shower surrounds and receptors of tile, concrete, or marble may be built to any desired size or shape. Typically
lead or plastic sheets are site-formed into shower pans on custom-made showers.

Preformed shower stall surrounds are most commonly available in sizes of 30 in by 30 in (760 mm by 760 mm)
and 30 in by 36 in (760 mm by 915 mm).

Steel shower surrounds are usually available in sizes of 30 in by 30 in (760 mm by 760 mm) and 30 in by 36 in
(760 mm by 915 mm).

Fiberglass shower surrounds are commonly available in sizes of 36 in by 36 in (915 mm by 915 mm) and 36 in
by 48 in (915 mm by 1220 mm).

Code generally sets a minimum shower size (except as permitted herein) of at least 1024 in 2 (0.66 m2) of interior
cross-sectional space with a minimum interior dimension of 30 in (760 mm). The only exception is a prefabricated
one-piece shower designed to accommodate a 32 in by 32 in (800 mm by 800 mm) roughed-in opening, provided
it has at least 900 in2 (.56 m2) of interior area.

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 6. LAVATORY
- a bathroom basin or sink used for personal hygiene. Lavatories are generally available in vitreous
china or enameled iron, or they may be cast in plastic or a plastic compound with the basin an integral
part of the countertop. They are also available in stainless steel for high-vandalism applications.

Present requirements for nonmetered lavatory faucets limit the average water consumption to 2.2 gpm (8.4
L/min). Metered lavatory faucets are designed to shut off after a short period of time. They are used in public
restrooms such as in transportation terminals, restaurants, and convention halls to ensure that water is shut off
and not flowing freely. Metered faucets used on lavatories should not deliver more than 0.25 gal (1.0 L) per use.
Infrared and ultrasonic sensors can be installed to operate faucets and limit waste.

Lavatories are available in a large variety of sizes and the shapes are usually:

a. square
b. rectangular
c. round
d. oval.

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The lavatory may be:

a. wall-hung
b. set on legs
c. set on a stand
d. built into a cabinet

Lavatory styles:

a. SELF-RIMMING LAVATORIES
- have a finished rim that is placed directly over the countertop opening.
b. UNDERCOUNTER LAVATORIES
- an installation in which a lavatory (or sink) is attached to the underside of a countertop.
c. PEDESTAL LAVATORIES
- have a basin that is supported primarily by a freestanding pedestal leg.

Special fittings for lavatories:

a. FOOT CONTROLS
- often used in institutions such as hospitals and nursing homes
b. SELF-CLOSING FAUCETS
- commonly used in public facilities (especially on hot water faucets) to conserve water
c. AUTOMATIC “NO-TOUCH” FLOW
- operates automatically when a sensor recognizes that hands are positioned under the faucet.
d. LIFT ROD
- Residential lavatories have a lift rod that opens the pop-up drain when the lift rod is depressed. When
rod is lifted, the drain closes so the lavatory will retain water.

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 7. SINKS

Kitchen sinks are most commonly made of enameled cast iron or stainless steel. Sinks are usually available in
a single- or a double-bowl arrangement; some even have a third bowl, which is much smaller. A waste disposal
is typically connected to one of the sink drains. Kitchen sinks are generally flush-mounted into a plastic laminate
or into a composition plastic counter. Present water conserving requirements for residential kitchen sink faucets
limits the average water consumption to 2.5 gpm (9.5 L/min). A common sink width for the kitchen is 30 in.

UTILITY OR SERVICE SINK

- has a deep, fixed basin that is supplied with hot and cold water and is used for rinsing mops and
disposing cleaning water. They are often called slop sinks or mop sinks. These sinks are made of
enameled cast iron or vitreous china. Most service sinks have high backs, and there may be two or
as many as three bowl compartments. Other sinks commonly used are laundry trays, pantry sinks,
bar sinks, and surgeon’s sinks. Service sinks are generally available in enameled iron or in stainless
steel.
FLOORMOUNT SINK
- installed into the center of a concave floor to dispose of water. The dome strainer and grate provide
a convenient drain and catch basin for general cleaning and maintenance tasks.

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 8. LAUNDRY TUBS OR TRAYS
- large deep sink used in laundry rooms. They are usually available in a single- or a double-bowl
arrangement. Laundry tubs are typically floor or wall-mounted units available in low-cost plastic,
enameled iron, or stainless steel.

9. DRINKING FOUNTAINS AND WATER COOLERS

DRINKING FOUNTAINS

- offer users a limitless supply of drinking water at any location where water and sanitary drainage are
readily available.

WATER COOLERS

- can deliver 8 gal/hr (30 L/hr) or more of chilled drinking water. They require connections to power,
water, and drainage.

Drinking fountains and water coolers are available in wall-mounted and floor units. Drinking fountains and water
coolers should not be installed in public restrooms.

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 10. OTHER FIXTURES

EMERGENCY FIXTURES

- include eye-face washes, drench showers, decontamination units, portables, and accessories
designed for use wherever hazardous substances are present.

Other types of fixtures:

a. baptisteries
b. ornamental ponds
c. fountains
d. aquariums.

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