LESSON 3: THE WASTE PIPE

EXPECTATIONS

You will know about the waste pipe, this module will help you to:

 Explain what is waste pipe and soil pipe.

 Identify the types of waste pipe.

 Recognize the plumbing fixtures for waste management.

 Perform on how to install a kitchen sink drain.

Let us start your journey in learning more on waste pipe.

LESSON PROPER

What is a waste pipe?

A waste pipe is often a smaller diameter pipe that carries waste water from sinks, washing
machine, shower, bath and any other appliance you may have that uses water. It can be
narrower than a soil pipe as the waste pipe is only designed to carry water. It also doesn’t need
the same venting system as a soil pipe. Wastewater does not typically generate harmful gas so
does not need to be vented high above ground level.

What is a soil pipe?

This type of pipe will carry water and solids into the sewer. While any pipe could
physically perform the task, the soil pipe, also known as a soil vent pipe, as installed in most
homes has a specific quality. First, it is of a dimension to allow solid waste to pass. Second, it is
vented in a very specific way to maintain a safe environment and reduce odors. Soil pipes are
vented high at the top or near to the top of a building to allow gases produced by waste to
vent safely into the atmosphere. Such gases can be harmful to health so venting them high
keeps them out of the way.

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Types of Waste Water Pipes

1. UPVC Pipes

2. Clayware Pipes

3. Fiber Cement Pipes

4. Concrete Pipes

5. Ductile Iron Pipes

UPVC Pipes

These UPVC pipes are used as waste water pipes for drainage purpose and have a superior
intensity and working pressure. They are environmentally safe, chemical resistant and provide
lasting quality. They are economical and easy in installation. They provide perfect water
tightness.

Clayware Pipes

Clayware waste water pipes are convenient in handling and layout. They have rigid fittings and
do not distort under loading. They maintain good corrosion resistance. These pipes provide
flexible joints at sufficient and frequent intervals.

Fiber Cement Pipes

These type of waste water pipes are resistant to corrosion and maintain qualities of both
concrete and inorganic fiber. They have a service life of minimum 50 to 75 years and do not
create any problems in storage. They remain unaffected in strength by high temperatures and
maintain thermal conductivity approximately 120 times less than metal pipes. They have
smooth bores and low friction losses.

Fiber cement pipes maintain their carrying capacity during service period. These waste pipes
improve with the passage of time and yield to better test results in terms of strength when
kept in humid environment. The ends of pipes can be turned into accurate dimensions. The
pipes can be drilled, cut, turned at the site of job by handy tools.

Concrete Pipes

These pipes are environment-friendly and provide structural strength. These are generally used
for carrying the waste water from the sewer line. They are resistant to abrasion and most
chemicals. They are easy to install and have a history of reliability. The pipes get stronger with
the passage of time and life cycle of a steel reinforced concrete pipe is considerably longer
than other drainage pipes.

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Ductile Iron Pipes

These pipes are chemical resistant and have high tensile strength. These waste water pipes are
best suitable for carrying the industrial waste. These are also resistant to second cover
damage. They are economical and easy in installation. They are not damaged while handling or
during transportation. They have high elongation (ductility).

Recommended size of waste water pipes

The diameter of waste water pipes should be based on fixture units. Branches and piles
receiving discharges from soil appliances should not be less than 100 mm diameter. Outlet of
floor traps may be of 75 mm diameter. Waste stack should have a minimum diameter of 75
mm.
Various colors indicating Sewer, Waste and Water Pipes
• Red color indicates sewers.
• Blue color indicates waste water pipes.
• Blue color marks rain water pipes also.
• Black color marks existing works.

List of Plumbing Fixtures for Waste Management

The sanitary fittings used in the drainage system of houses and buildings include:
1. Wash Basins
2. Sinks
3. Bath Tubs
4. Water Closets
5. Urinals
6. Flushing Cisterns.

1. Wash Basins

Wash basins are the plumbing fixtures provided for washing hands and face and brushing teeth
in a standing position. These are usually made of glazed earthenware or vitreous china.
Sometimes these are also made of enameled iron, stainless steel or plastic, especially where
the number of users is more. The wash basins may be of either flat back pattern for fixing on
walls, or angle back pattern for fixing at the junction of two walls.

The standard sizes of these wash basins are as indicated below

(a) Flat Back Pattern – 630 x 450 mm, 550 x 400 mm, and 450 x 300 mm
(b) Angle Back Pattern – 600 x 480 mm and 400 x 400 mm
2. Sinks

Sinks are the plumbing fixtures provided in kitchens for cleaning utensils. These are also
provided in laboratories for cleaning laboratory ware. Sinks are usually of rectangular shape
and are made of glazed earthen ware or vitreous china, cement concrete with or without
terrazzo finish, marble, stainless steel and enameled iron.

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The usual sizes of the sinks are as indicated below:

(a) Laboratory Sinks (b) Kitchen Sinks

400 x 250 x 150 mm 600 x 450 x 150 mm

450 x 300 x 150 mm 600 x 450 x 250 mm

500 x 350 x 150 mm 750 x 450 x 250 mm

600 x 400 x 200 mm

3. Bath Tubs

Bath tubs are the plumbing fixtures provided in the bath rooms for taking bath. These are
usually made of glazed earthenware or vitreous china, cement concrete finished with terrazzo
or glazed porcelain tiles or marble titles and enameled iron. The bath tubs are provided with a
circular waste hole at the bottom for draining.

The waste hole is provided with a metallic waste fitting also called waste coupling having a
strainer and a clear opening of about 40 to 50 mm diameter. A waste pipe with a trap is fixed
to the waste fitting. The bath tub is provided with tap/shower and an overflow pipe of
diameter 40 mm located at 40 to 50 mm below the top edge of the tub.

For holding water in the tub a rubber plug attached to a chain secured by a stay is provided.
The chain stay hole is of 10 mm diameter and it is located slightly above the overflow pipe. The
usual dimensions of a bath tub are: length 1.8 m, width 0.75 m and depth 0.45 m. The overall
height of the tub including feet is about 0.6 m.

4. Water Closets (W.C.)

A water closet is a pan like water flushed plumbing fixture designed to receive human excreta
directly from the user. It is made of vitreous china or porcelain and is connected to the soil pipe
by means of a trap. The inside surface of the water closet and the trap is made smooth by
glazing in order to ensure an efficient flush.

The water closet has an integral flushing rim with adequate number of holes to spread the
flushing water. The water closet also has an inlet or supply horn for connecting a flushing
cistern or a flushing pipe fitted with regulating valve, to flush the water closet and discharge
the human excreta to the soil pipe.

Water closets are of the following three types:

(i) Indian type or Squatting type;

(ii) European type of Pedestal type; and

(iii) Anglo-Indian type

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5. Urinals

Urinals are the plumbing fixtures provided for the purpose of urinating.

These are usually made of glazed earthenware or vitreous china and are of the following four
types:

(i) Bowl type

(ii) Slab type

(iii) Stall type

(iv) Squatting plate type

6. Flushing Cisterns

Flushing cisterns are the plumbing fixtures provided for flushing out water closets and urinals.
These are made of cast iron, glazed earthenware or vitreous china, or plastic. For Indian type
water closets normally cast iron flushing cisterns are used which are fixed with their bottom at
a height of 1.25 m above the top of the closet pans and these are known as high level flushing
cisterns.

For European type and Anglo- Indian type water closets usually flushing cisterns of vitreous
china or plastic are used which are fixed with their bottom at a height of 0.3 m above the top
of the closet pans and these are known as low level flushing cisterns.

Flushing cisterns are of two types:

(i) Valveless siphonic type, and

(ii) Valve fitted siphonic type.

ACTIVITIES

Install a Kitchen Sink Drain

Equipment / Tools
• Tape measure
• Marker
• PVC tubing cutter or hacksaw
• Channel-type pliers

Materials
• Kitchen drain trap kit
• Teflon

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Procedure:
1. Check the Drain Outlet Height
If you're planning to replace a standard sink with a deep-basin sink, you may need to lower the
drain fitting in the wall to match the lower height of the new sink drain. Before you buy a new
kitchen sink, it is a good idea to check the height of the trap arm on the old sink. The trap arm
is the horizontal piece between the U-shaped trap bend (the P-trap) and the branch drain pipe
in the wall. It connects to a sanitary tee fitting in the branch drain and should slope down
toward the tee at about 1/4 inch per foot for proper drainage.

2. Lower the Drain, If Necessary

If you find that the existing drain opening is not low enough to accommodate the depth of the
new sink, you (or a professional) will need to open the wall and lower the position of the
sanitary tee connecting to the drain pipe in the wall. This can be a somewhat complicated job
that requires cutting away the back of the cabinet and the wall surface.

3. Install the Garbage Disposal and Strainer

Install the garbage disposal onto the desired side of the sink first, since this takes up the most
space. Install a basket strainer onto the sink basin without the garbage disposal. This is also a
good time to install any other under-sink components, such as a water filter or a hot water
dispenser.

4. Install the Tailpiece and Continuous Waste Pipe

The drain tailpiece is a straight pipe that connects to the sink strainer and runs down to a tee
fitting (below the sink basin without the disposer). The continuous waste pipe connects the
disposal's drain to the tee fitting. The tailpiece and waste pipe must be cut to length for
installation.

5. Connect the Drain Trap

The drain trap assembly includes the U-shaped trap bend and a J-shaped trap arm. The trap
bend fits onto the bottom of the tailpiece tee fitting, while the trap arm extends into the
sanitary tee at the wall.

Assemble the trap bend and trap arm together loosely with a slip nut and washer. Slide a slip
nut and washer onto the straight end of the trap arm. Push the trap bend up into the tee fitting
on the tailpiece while sliding the trap arm into the sanitary tee at the wall.

Adjust the trap pieces as needed to create the most direct path from sink to the wall tee. Make
sure the trap arm has a slight downward angle toward the wall tee.

6. Check for Leaks

Run water in both sink basins and check for leaking at each pipe joint. Tighten up any
connections that leak. Conduct a final test by filling up each sink basin and letting it drain while
you check for leaks below.

It's not uncommon to get a little leaking with slip-nut joints. Usually it needs just some minor
adjustment. If initial tightening doesn't stop the leak, back out the nut, reposition the washer
and re-tighten the nut, making sure it's not cross-threaded.
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 REMEMBER

Methods of joining

Tip: Waste pipe often has the information about the material, diameter etc marked along its
length, when assembling the pipe, make sure that this is positioned so that it cannot be seen.
Connectors often have their details moulded in on one side, where possible arrange connector
so that these markings are hidden.

3 different methods of joining and sealing pipes are available:

Solvent: pipes and connectors of some types of plastic can be bonded

together using a special solvent cement. These plastics tend to be the more expensive available
but are easy to use. The major drawback of this type of waste pipes/connectors is that you only
have one chance to make the connection, once connected there is no chance to adjust the
angle or length without taking a hacksaw to the joint and remaking it with new pipe and
connectors. If a joint is likely to be broken in the future for any reason, solvent type joints
should not be used.

'O' ring: these connector can be used of all types of pipe of the
appropriate diameter. To make a connection, the pipe is just pushed into the connector
through the 'O' ring thus making the seal. Once the connection is made, the angle of the
pipe/connector can be adjusted by gripping the pipe and connector (one in each hand) and
twisting the pipe. If necessary to shorten lengths, the pipe can be pulled out, cut and re-
inserted. To ease pushing the pipe into the connector, the end of the pipe should be lightly
chamfered before insertion so that the pipe can easily start to enter the seal.

Compression: Compression waste pipe connectors are often used

to terminate waste pipes into the outlet of the waste trap under basins, baths and sinks.
However inline connectors are also available using compression joints, these are the most
expensive type available and their use is generally not warranted unless a particular bend or
joint is likely to need to be broken on a regular basis. The compression screw and seal are
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removed from the connector and slid onto the pipe, the pipe is then inserted (requiring no
effective effort) into the connection, the seal is then pushed along the pipe into the mouth of
the connector and the screw is wound onto the connector making the seal compress between
the pipe and the connector. To adjust or remove the pipe, the screw cover is undone thus
releasing the seal, the pipe can then be adjusted or removed with no effective effort.

References

1. https://www.creativesafetysupply.com/articles/pipe-colorcodes/

2. https//www.drainage how does a soil pipe differ from a waste pipe, Drainage Superstore
Help & Advice

3. https//www.List of Important Plumbing Fixtures | Waste Management

(environmentalpollution.in)

4. http://www.gharexpert.com/tips/articles/Construction/1791/Soil-Waste-Drainage-Sewage--
1791-Various-Waste-Water-Pipes-Sewer-Construction-_0

5. https://www.thespruce.com/how-to-install-a-sink-drain-
2718789#:~:text=The%20pipe%20should%20slope%20downward%20slightly%20toward%20th
e,with%20a%20PVC%20tubing%20cutter%20or%20a%20hacksaw.

6. https://www.diydata.com/plumbing/waste_pipes/waste_pipes.php