RP-01638

Malaysia
Goh Sing Yau
The population of Malaysia is approximately
13 million and about 70% of the population
live in rural areas. More than half of the rural
households are not served with piped water
supplies. In the late 1960s, the Environmental
Engineering Unit (now renamed the Engineering
Services Division) of the Ministry of
Health initiated a program to improve the
rural water supply. Part of the program
involved the drilling of 2000 new tube wells
every year and fitting therri with handpumps
each to serve four or five households.
At present, all handpumps installed by the
Ministry of Health must be imported. Because
of the relatively high water table in most
lowland areas in Malaysia, most handpumps
installed by the Ministry of Health are of the
suction type, such as the Dragon, Fuji, and
Gibson handpumps. A limited number of lift
handpumps such as the Dempster and the
India Mark II have been installed in deeper
wells in hilly terrain. The Ministry of Health
has found that the suction handpumps often
do not last much longer than 1 year. The lift
handpumps, which cost much more than
suction handpumps, are more robust in their
construction and last longer. However, spare
parts for both the suction and lift handpumps,
especially the cast metal components, are not
readily available locally. This had led to the
practice of cannibalizing parts to keep some of
the handpumps in operation while others are
abandoned for lack of spare parts.
This joint project between the Ministry of
Health and the Department of Mechanical
Engineering of the University of Malaya was
initiated in an attempt to overcome some of
these difficulties. The main objective of the
project was to develop a relatively inexpensive
handpump that could be produced locally
from locally available materials. The handpump
was to be a simple design that could be
maintained by users at the village level.
Although handpumps have existed for a
long time, many recent studies have been
prompted by the recognition that they still
have an important role to play in providing
safe drinking water to the majority of the
rural people in developing countries. In 1978,
the International Development Research
Centre (IDRC) encouraged the development
of a PVC plastic handpump for use in developing
countries. Initial studies were conducted
at the University of Waterloo and further
tests were carried out by the Consumers'
Association in the United Kingdom. The major
advantages of the polyvinyl chloride (PVC)
plastic handpump over traditional cast-metal
handpumps include: (1) simple fabrication
procedures because PVC parts can be solventwelded
together; and (2) maintenance by users
at the village level is feasible because PVC is
relatively light and removal of the handpump
assembly from the well for inspection and
maintenance is easier.
Present Study
The results reported here cover the period
January 1979-June 1982. The first phase of the
project lasted approximately 1 year and
involved an analytical study and parallel
experimental investigation to determine the
critical parameters for an optimum design for
the plastic reciprocating handpump. During
the second phase of the project, 17 handpumps
were fabricated and field tested in two rural
areas for 8.5 months.
For the purpose of this report, details of the
laboratory investigation have been omitted
(see Goh 1980).
The reciprocating piston handpump considered
here consists essentially of a draw
pipe with two identical valves. The bottom
valve (foot valve) is in a fixed position at the
bottom of the draw pipe and is immersed in
water. The upper valve (piston valve) is
attached to a piston rod that moves the
piston valve in a reciprocating motion a short
distance above the foot valve. The cycle of
operation is illustrated in Fig. 1.
Theoretical Analysis
From an analysis of the forces acting on the
piston rod for each stroke of the operating
cycle, a corresponding force-displacement
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