CHAPTER 10
PLUMBING EQUIPMENT AND SYSTEMS
OVERVIEW
It is not an easy task to condense the entire subject on plumbing equipment and systems into one
chapter. Needless to say, we can only cover the bare fundamentals in this single chapter. Thus,
all topics are very brief. If time allows in your class schedule, you may wish to expand certain
aspect of this topic in your class. For example, you may wish to expand the water supply and
storage topic if students are majoring in landscape architecture, or urban planning; kitchen and
bathroom design for architectural and interior design students, and additional information on
equipment and piping layouts for engineering and construction management students.
One important message to the students should be to increase their interest and therefore their
attention on the importance of plumbing systems in society – its impact on public health and life
safety. Without water and proper waste control, no building could be used for human
occupancy. Thus, the design of water supply and drainage piping systems must be strictly
designed and installed according to codes. In fact, building mechanical and plumbing codes are
so restricted which makes the design of these systems rather straight forward without much
alternative. However, code requirements are only minimum requirements normally sufficient for
small systems. The design of large plumbing systems will require considerable engineering and
computer calculations so as to make the systems work properly and economically.
There are many newer automatic reliable flushing devices for water closets, urinals and
lavatories. These may become the standard or code-required installation in public buildings in
the near future. Water conservation control is another issue that should be discussed.
The material included in this chapter should take 6 to 8 class-hours to cover in the class. It can
also be taught in conjunction with Chapter 11: Fire Protection Equipment and Systems as a
separate 1-credit hour course.
CHAPTER 10
PLUMBING EQUIPMENT AND SYSTEMS
QUESTIONS AND ANSWERS
10.1 Do National Plumbing Codes provide sufficient data and guidelines for designing a
sanitary drainage system? If so, explain.
10.2 Do National Plumbing Codes provide sufficient data and guidelines to design
a domestic water distribution system? Explain.
10.3 Name the major of water quality.
10.4 Name the seven processes used to improve the quality of water.
The processes commonly used to improve water quality, in sequence of processing are:
10.5 What mineral content is used to determine the hardness in water?
10.6 Describe the Zeolite water softening process.
10.7 What is osmosis? Reverse osmosis?
10.8 What are the two commonly used water filtration systems?
10.9 A light commercial building is installed with four flush tank type water
closets, two urinals with flushometers, and four lavatories. What is the total water
supply fixture units (wsfu)? What is the probable water demand?
10.10 A building is installed with 300 tons of air conditioning. The air conditioning unit is
water cooled through a cooling tower. How much make-up water should be provided?
10.11 What is the pressure drop due to friction loss for 400 feet of one-inch PVC
pipe with a flow of 10 gpm?
10.12 What is usually assumed as the equivalent length (EL) of pipe fittings in a
plumbing piping system? (Note: This procedure applies to preliminary design only).
10.13 What is the pressure at the base of a water pipe feeding a plumbing facility
500 feet above the base due to static height alone?
10.14 What is the hot water demand for a residential dishwasher in gpm and total
consumption?
10.15 What type copper pipe is normally used for domestic water system?
10.16 What is the function of a vacuum breaker?
10.17 What is the function of a shock absorber? Where should they be installed?
10.18 What is the most effective method to prevent backflow?
10.19 Why is a flushometer required for water closets in lieu of flush tanks in public
facilities?
10.20 What is the water demand for a pressure tank type water closet per flushing? For
standard gravity tanks?
10.21 What is the purpose of a drainage trap? Do water closets require traps?
10.22What is the nominal rating in drainage fixture units (dfu) of a water closet with
flushometer? with gravity tank?
10.23What is the difference between waste pipe and soil pipe?
10.24What is a bathroom group? What is the wfu of a bathroom group with flush
tank? What should be the minimum soil pipe diameter?
10.25 A secondary school is planned for 2,000 students, teachers and staff. Assuming the
population is 50% male and 50% female, determine the minimum number of plumbing
fixtures required. In your judgment is this adequate?
Based on the general requirements shown in Table 8-7, the number of the
minimum plumbing fixtures recommended for the secondary schools are:
• Water closets for male: 1000 /
30 = 34 (use 17)
be sufficient.
10.26 Calculate the minimum number of plumbing fixtures for a 500 seat movie
theater. Based on your judgment, is this adequate?
10.27 What is a stack? a vent? a stack vent? and a vent stack?
10.28 What is the purpose of a stack vent?
10.29 What are the piping materials commonly used in drainage piping systems?
10.30 Normally, municipalities in the USA have separate sanitary and storm sewer
systems. There are, however, several major cities which still have combination storm
and sanitary sewer systems. In such case, can the sanitary and storm piping systems
within the building be combined?
10.31 Give the major steps in a sewage primary treatment system, and the
secondary treatment process.
10.32 What is the purpose of a dosing chamber in a septic tank sewage treatment
system?
10.33 What is the minimum size septic tank for an apartment building with 10 one-
bedroom units?
10.34 In addition to the sanitary facilities, what other water drainage shall be
considered in plumbing system design for a large building complex?