[PDF]Manual for Water Systems and Pipe Works

Jlffl MICROFICHE
MM I REFERENCE
Al LIBRARY

A project of Volunteers in Asia



M anual for Water Systems and Pipe works

by: Andreas Bachmann and Nirman Joshi

Published by:

Swiss Association for Technical Assistance

P.O. Box 113

Kathmandu

Nepal

Free to serious groups.

Available from:

Swiss Association for Technical Assistance

P.O. Box 113

Kathmandu

Nepal

Reproduced by permission of the Swiss Association
for Technical Assistance.



Reproduction of this microfiche document in any
form is subject to the same restrictions as those
of the original document.



MANUAL



FOR

WAT ER SYSTEMS
AND
PIPE WORKS



A BRIEF



INTRODUCTION COURSE

FOR THE ESTABLISHMENTS
OF RURAL WATER SUPPLIES
IN NEPAL



PREPARED BY! ANDREAS BACHMANN, SATA
NIRMAN JOSH I , DRAFTSMAN



SWISS ASSOCIATION FOR TECHNICAL ASSISTANCE,
S ATA, P.O. BOX 113
KATHMANDU/ NEPAL



PREFACE



As rural water supplies became one of the prime tasks for
the Himalayan Kingdom of Nepal it was soon recognised that
plastic pipes would play a major role for the mostly quite
difficult hilly terrain.

The first manual was worked out for Peace Corps workers
in autumn 1974. It shows the basic principles of pipe work.
It has since then been several times reprinted, also at the
special request of the Nepal Government, Water Department.

It is hoped that this new edition will be useful for many
more field workers willing to assist in improvements of
living conditions in rural areas.

Andreas Bachmann
S A T A / Kathmandu
June 1980



CONTENTS



1. Introduction

1.1. Importance of water ,. l

1.2. Development of sources, quality and quantity ... 2

2. Water Supplies

2.1. Natural Gravity System 3

2.2. Pumpei . Gravity System 4

2.3. Hydraulic Ram 5

2.4. Loss of Head. / Chart 6

3. Water Conduit

3.1. Trenches and Pipelines 7

3.2. Manhole, Special Standpipe 8

3.3.. Water Prevention Device 9

3.3. Water Prevention Device / Sketch 10

3.4. Water Place, Standpipe 11

3.5. Valves 12

3.6. Special Valves 13

4. Galvanized Pipes

4.1. Use, rules, pipe measurements, length of threads . 14

4.2. Thread, cutting, watertight joints and threads 15

4.3. Nipple cutting, connection to concrete 16

4 . 4 . Galv. Fittings 17



5.



Plastic Pipes



5.1. Introduction X8

c 7 Transport and Storage 19

5, .: . Preparation of Trenches and Laying of Pipes 20

5.4. Connection of Galv. Pipes and Plastic Pipes '. . 21

6. P V C - Pipes



6.1. Use, rules, preparing of a spigot end 22

6.2. Solvent cement joints, points to remember 2 3

6.3. Sockets and Bends 24

7. H D P E - Pipes



7.1. Use, Rules , . 25

7.2. Handling of Pipe Coils 26

7.3. Weiddng 27

7.4. Branch 45° 28

7.5. Branch 60° 29

7.6. Branch 90° , f 30

7.7. Bends and Elbows 45° + 90° 31

7.8. Endcap 32

7.9. Conical Reducer .,».,..,,.,. 33

7.10. Endcap ( and 1st. step for low-pressure reducer ) 34

7.11. Reducer ( low pressure ) 35

7.12. Reducer, for small differences in diameters 36

7.13. Reduced Branch 37

7.14. HDPE - Tools 38

7.15. Blow Lamp ........... 39



1.1. INTRODUCTION



Importance of Water



- Water is essential for: life

- Water is essential for health and sanitation

- Water is the principal raw material for food production

- Water is important for many uses outside the home

and on the farm

- Water conservation and- sanitation are important to

everyone

The Water Cycle




S = SPRINGS P = POROUS STRATA

SW DW = SPRINGS OR WELLS X Y = WATER T I G HT

ART. W. ARTESIAN WELL STRATA



A cross section of a possible arrangement of the earth crust show-
ing how water may be distributed over and through it.

A part of the rainfall runs off at the surface forming creeks and
rivers; a part may soak into the ground and return to the surface
at springs or wells.

Yet another portion may percolate deeper through cracks and faults.
( A-A and B ) into a porous strata (P) where it may be carried many
kilometers to the ocean or to artesian wells..



Sources of water for domestic use



Rain Water - Natural Surface Water - Ground Water



-1-



1.2. INTRODUCTION



Development of sources of water



Any new or untried source of water should be examined for quality
before expensive development is undertaken.

For watering animals, sprying and irrigation it should at least be
clear and free of any materials, minerals, tastes or odors, which
would be harmful or objectionable to plants or animals.

Quality



The water must be free of - harmful bacterias

- objectionable minerals

- tastes or odors

- sediment = to be clear, without color

- temperature low (appr. 10°C (50 °F)



Quantity
need for life
need for life

Definations as applied to



- 15 ltr (appr. 31/2 gallons)
per day and person

- 50 ltr (appr. 11 gallons)
per day and person



When used in connection with handeling water, head refers to the
vertical height of a column of water above a certain point, and is
considered as causing or counteracting the flow of water.
For example, if water stands at a height of 6 meters (20 feet) ,
.there will be 6 meters (20') of head in the bottom of the pipe.
This pressure is expressed in terms in kg per cm2 (or pounds per
square inch, psi) . A column of water with 10 meters of height"
(10 meters head) will have a pressure of 1 kg/cm2 (At 6 m = 0.6
kg/cm2) .



Gravity head
Pressure



Suction head



is the actual vertical height of a column of water
above the reference point.

Pressure head is the vertical height in meter (feet)
to which any given pressure will force water. One kg
per cm2 will force water to a height of 10 m.
(or one pound to a height of 2.3 feet).

a term applied to pumps, is considered as the total
quivalent head in meter (feet) on the suction side
of the pump against which the pump must work in orde
to get water.

The quivalent suction head is made up of
gravity head + friction head



Most pumps are guaranteed to work against 7 m (22')
of total suction head at sea level (As more the alti
tude as less can be the suction head) I



-2-



2.1. WATER SUPPLY



NATURAL GR AVITY SYSTEM



-DIVERSION DITCH



OVERFLOW, OPEN OUTLET
JDO NOT FIX ANY VALVE)




2

CATCHMENT BASIN
STRAINER

KEEP STRAIGHT
PIPE FOR EASY
CLEANiNG.



be in a way
can flow out,



Spring catchment must
that the water." always
without damming up the water level.
Ther3 must also be an overflow with-
out any valve.

The outlets have to be covered with
screen, so that no dirt or animal
can block the pipe.

Gravity Type



A gravity water system is one having a tank or a storage reservour
located higher than the faucets from which tank or reservoir water
flows to the faucets by the force of gravity.

There are two common types of gravity systems. One is "natural"
gravity where the source of the water is high enough above the fau-
cets to provide a satisfactory flow. The other is the "pumped" sys-
tem where a pump is used to elevate the water to a gravity storage
tank located above the faucets.

Natural Gravity System



The natural gravity system should be considered only when the source
of water is high enough above the faucets (stand pipe's or buildings)
to give adequate flow.

Unless the spring has a strong flow, a catchment basin should be
built below the spring as shown. For a satisfactory flow there may
be at least 7 meters (22') of elevation on the highest faucets. If
the system has a great distance, more then 7 meters is desirable.

A source to be tdeveloped shoul c provide an adequate year-round
supply of good quality water. Special attention should be given to
catchment basins, size and material of pipe to use, and protection
from contamination or pollution.



2.2. WATER SUPPLY



PUMPED GRAVITY SYSTEM




-FOOT VALVE

CLEAR WATER CHAMBER
-VALVE FOR CLEANING AND CHECKING
OF FOOT VALVE
•WELL SCREEN OR PERFORATED PIPE



SH- Suction Head. Has to be as low and short as possible. The
head is made up of gravity and friction (= loss) . The absolutely
maximum of head (GH + FH) is 7m (22') at sea level .

Pumped Gravity Systems

If there is no possibility for a natural gravity system, there re-
mains the pumpe 1 gravity system. But they are not always recommend-
able: pumps are expensive, need quite some maintenance (service
through specialists) may use expensive fuel, with the exception of
the Hydraulic Ram.

However, for big quantities and/or if there is only this possibility
it is a very satisfactory system.

A large storage capacity is desirable to provide water for days, it
needs a less frequent starting of the engine.



2.3. WATER SUPPLY



Hydraulic Ram *

The Hydraulic Ram is an automatic pump which by means of a ^.-lativelv
small gradient raises a part of the available spring or stream water*
to a much higher point.

Example: The spring or stream water is being collected in a reser-
voir. From here a part of this water is to be lifted to the supply
reservoir. For this purpose the water is being fed through a pressure
pipe into the ram. A part of this volume is then being raised through
the supply pipe to the reservoir.

The proportion between pressure pipe quantity + supply pipe quantity
can be

from: 100 % up to 3 %
100 % up to 24 %



L = LENGTH OF PRESSURE PIPE
A= 30-40 cm (12-16")
B= AT LEAST 10 CM ( 4"



4-5 x H



FROM THE
SOURCE




OVERFLOW AND
CLEANING PIPE



RAM



SUPPI
RESER-
VOIR, SEE
PAGES W.
GRAVITY
SYSTEMS



FLUSH OUT
(ESSENTIAL)



Collecting Reservoir : The water available is collected in a reser-
voir or basin. As far as the water is taken from a stream, this lat-
ter can be dammed up for this purpose. The collecting tank can be
made in any desired size. It is however essential, that the pressure
pipe intake is always covered under at least 30-40 cm (12-16").
The collecting reservoir must furthermore be construcetd in a way
which excludes any possibility of air bubbles entering the pressure
pipe. Air bubbles in the pressure pipe would hamper the proper oper-
ation of the ram.

Pressure Pipe : the pressure pipe line must be installed with a great
care. It must in particular be absolutely tight.

Caution : An installation of a ram is a very particular matter, it
needs founded knowledge. Before ordering a hydraulic ram, contact
a specialist.



-5-




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3.1. W A/'T E R CONDUIT



Pipelines: don't bring drinking water to a place before the drains
*s assured! (MOISTURE brings insects and illness) .



-PIPE MARKING/ PIPE WITH SAME DIAMETER
OR BIGGER, FILLED WITH CEMENT, WITH
MARKS OF DIRECTION

KEEP FREE FOR WALKING ANU
TO PREVENT STONES FALLING
ON THE PIPF

EXCAVAT ED
ATERIAL




DEPTH OF TRE
AT LEAST 1 M
AT ALTITUDES
FROST EVEN MOR



IL, WITH-
T STONES



TRENCH BOTTOM



Before refilling a trench: -make sure that the pipe system is

tight, waterproof!
-make a plan how the pipe lies in the
ground.

Pipes should be in the ground, where they are protected against me-
chanical damage. The temperature also will be better.
The depth of a trench may be at least l.o m (3'-4"), otherwise
there could be the risk that they will be dug out by the farmers
for irrigation,.

Don't let pressure in the pipeline before the trench is filled up
in the correct way. Otherwise remains the risk, that it will never
be done:

Always look through the pipes before you install them and close
the open ends immediately, and if it is only for a few minutes:

-7-



3.2. WATER CONDUIT



Manhole

By changing the direction in the ground make always big bends.

The best solution (by low pressure distribution only) is a manhole
This for the reasons of cleaning and also for blocked pipelines.

Pipelines in the ground should have a diameter of at least 1 V4"
(Excepetions: branchline to standpipes) .




Standpipe with reservoir and pump

Water shortage, remains a good possibility, as shown. Shortage be-
cause there is not enough water, or because the people don't close
the valve.



BALL VALVE




Y, RESER
, - X VOIR



1 I SBS



OUTLET
HANDPUMP



OVERFLOW ( * Ml N 1' )
-CLEANING PIPE W. CAP (MIN. 2'*)









1



















nxn



DRAIN



6O0



FOR STAIV °E CONSTRUCTION SEE SEPARATE PAGE



-8-



3.3. WATER CONDUIT



Water Prevention Device (WHO-Design)

This shows an idea for a waste prevention standpipe. This is less
applicable to the type of hand-pumped supply, but for aravity or
piped systems.

The principle is based on the fact that most common water container
used in many parts of the world is a kerosene tin which holds littl<
less than 20 liters. A standpipe constructed of a pipe with 150 mm
diameter (6"), inside which slides a free piston. The capacity of
the 150 mm pipe in the appr. 1 meter length between the top of the
piston in its lowest position and the outlet top is 20 liters.

. "s piston incorporates a short length of small diameter pipe, say
> mm diameter which, by passing water from below to above permits
che piston to sink slowly by its own weight when the pressure on
the two sides is equal, so that its normal position is at the botton
of the standpipe. Its weight is adjusted so that it will raise under
the pressure of incoming water when the tap is opened, and sink as
described when the tap is closed.

When villagers open the tap, water from the top side of the piston
runs into her container, and the piston is raised by the water ores-
sure below. When 20 liters has been withdrawn, the piston reaches
its highest position, and the mouth of the 10 mm pipe seals itself
against the rubber stop. As long as the tap remains open, the water
pressure below holds the piston in this position, and no more water
can be drawn off. In order to fill another container, it is necessar
to close the tap long enough for the piston to sink its lowest posi-
tion, where another cycle starts.

( see vef, WHO )

Self Closing Hydrant

The idea is brilliant. When the hydrant is made by professionals it
surely works to perfection, but when made at home by a more or less
skillful mechanic, it is not quite succesful. Unless the mechanic ha
the necessary tools to make the inside of the tube perfectly smooth,
and to give the piston the very close yet free running fit, the hy-
drant will leak. This has been the experience.

We would suggest a slight change. Instead of having the outlet pipe
at the side of the tube to be blocked by the piston put it in the
center at the top of the tube. This way the very outlet is plugged,
and even if some water does leak past between the piston and tube
merely goes above the piston, but simply cannot flow out.

Another useful suggestion: eliminate the tap. Taps manufactured in
the Orient are a perpetual source of trouble. Four of our taps that
worked well were stolen, one after the other. The open end of the
outlet can quite easily be blocked by the user's hand till the pis-
ton drops.

( see ref, MINI TECHNOLOGY '



«.9_



3.3. WATER COND



U I T



Waste Water Prevention




1) left: Piston at bot-
tom of standpipe, be-
fore drawoff commences.

2) right: Pistion rai-
sing as water is drawn.



,a '.a- oV».



isfi





10 mm pipe



Piston slide fit
in standpipe




tap closed



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