SEWER

1
(No Transcript)
2

• SEWER
• PIPING DESIGN
• Sewer piping differs from water piping, in that
  sewer pipes are not under pressure. The function
  that takes place inside sewer pipes is at ambient
  atmospheric pressure, and the influence of
  gravity.
• Sewer pipes drain because they are installed on
  a slope and fluids flow downhill. The slope of
  sewer lines is a consideration because most
  effluent floats, and slow movement of the drain
  allows solids to flow unobstructed. But if the
  flow is too rapid, larger solids tend to tumble,
  and become a potential for clogging a drain pipe.
  Ideally, a horizontal sewer drain is never more
  than half full.
• Drain lines that must traverse excessive height
  in a short lateral distance are installed with
  vertical drops rather than excessive slope.

3

• Drain pipes are installed so the slope is
  consistent from the location of the fixture that
  is farthest from the entrance into a public
  drain, or to some suitable disposal.
• For this reason, the slope of drain pipes is
  critical to their efficiency. If a drain from a
  fixture in an intermediate area in a system is
  installed lower than the consistent point in the
  drain system, effluent will collect in the low
  areas, and the system will not drain well.

4
flow
In addition to consistent slope, it is a
requirement of the plumbing code for all turns in
direction of piping be done with 45 degree
fittings in the direction of flow, rather than
90. This facilitates the movements of slow moving
solids through a drainage system.
5

• CROSS SECTION
• THROUGH SINK
• OR LAVATORY
• DRAIN AND VENT
• Without a vent for
• supply of air to
• replace fluid in
• the drain, siphon
• action would pull
• the fluid out of
• the trap

A vent provides a path to Expel toxic sewer gas
to The atmosphere
Non-integral trap
Non-integral trap
6
WATER CLOSETS - Types of Discharge
Blowout Public - Loud
Siphon Jet Residential - Quiet
The seal area in the diagrams indicate the
integral trap. Because of the water that remains
in the bowl, sewer gas is blocked from coming
into the room .
7

• The sizing of pipe for drainage is far less
  complex than that for water piping, as there is
  no pressure involved, no rate of flow of water,
  and distance makes a difference only in that
  enough slope must be available to accommodate the
  drainage.
• Three charts are pertinent to drainage.
• The first chart lists the fixture unit value
  for fixtures, which are not quite the same as for
  water supply fixture units.

8
(No Transcript)
9

• The next chart shows the size of non-integral
  traps. A non-integral trap is a drain from a
  fixture to a building drain line, such as the
  drain mechanism beneath the lavatory in the bath
  room or beneath the sink in the kitchen.
  Non-integral means that the drain is not part of
  the fixture.
• An example of an integral trap is a water
  closet or a urinal, which have their own traps,
  because of the way they are made.

10
(No Transcript)
11

• The third chart is the one related to
  determining the collective size of drain pipes in
  a system. The fixture unit values of each unit
  determines the size of each segment of pipe in
  the system that serves the fixtures.
• The logical sequence for determining pipe size
  is first to draw a plan of the building, showing
  all the fixtures that are to be installed. A
  line that represents the drain pipe is drawn to
  connect the fixtures, which extends out of the
  building to an available drain deposit, such as a
  municipal sewer system.
• Beginning at the high end of the system, the
  fixture unit value for each segment of pipe is
  shown. Then from the following chart, the size of
  drain pipe is found.
• The far left column indicates drain pipe
  diameter. Notice the top of the chart shows
  various degrees of slope for drain pipe. For
  this course, use the column that allows for a
  slope of ¼ per foot. The numbers in the body of
  the chart are total fixture units allowed by the
  pipe sizes for the slope given.

12
scratch
13

• Remember that a Water Closet requires a 3
  drain, and you cannot install more than two Water
  Closets on a 3 drain. A drain line that has
  more than two water closets must be a minimum of
  4 diameter, regardless of how many fixture units
  it supports.
• The next slide shows the drainage plan for the
  residence that was used to calculate water
  supply. Realize that the drainage plan is to
  determine pipe sizes for what is called rough
  plumbing, which is that part of drainage that is
  installed below the floor and in walls. The
  smallest pipe generally used in rough plumbing is
  2 diameter.
• Finish plumbing, or trim is the parts of the
  plumbing system one can see, beneath cabinets,
  under fixtures, etc., and is made of materials of
  a better finish for appearance and ease of
  cleaning.

14
(No Transcript)
15

• The next sessions will include plumbing waste
  for fixtures that are stacked more than two
  story, and the method for determining vents and
  size of vents.

16
(No Transcript)