Farmers Review Africa July/Aug 2017 Farmers Review Africa July/Aug 2017 | Page 66

Supplement Borehole casing & screens
However, longitudinal slots are highly prone to
clogging which is a major limitation with respect
to efficiency and productivity.
Clogging in longitudinal slots comes about
because the parallel sides of the slot tend to trap
and retain sediment particles. is problem
becomes more pronounced in thicker walled
pipe. Summar y PVC pipe is a low-cost
alternative well casing and screen material that is
appropriate in some instances/applications
under speci c conditions.
However, for large-diameter water wells any cost
savings offered by PVC are clearly offset by its
limitations in tensile strength, collapse strength,
a n d h e at t o l e r a n c e .  e s e f a c t o r s a r e
troublesome for these wells and have the
potential to be serious structural de ciencies.
3.
Imperial Plastics LTD.
Borehole casing pipes and screen pipes are
manufactured from unplasticised polyvinyl
c h l o r i d e p o l y m e r ( U P VC ) w h i c h i s a
thermoplastic material.
e company manufactures the UPVC pipes at
the factory situated along Kafue Rd. Shimabala,
Lusaka, Zambia.
e company produces UPVC pressure pipes of
South African bureau of standards 966:1-
2010.e casings are available from 100mm to
200mm and are designed to go up to depths of
150 meters depending on correct ground
conditions
e casing pipes are available with male – female
ash threading. Horizontal slots (screens) enable
laminar ow into the well reducing well entrance
losses. e threaded joint provides easy, perfect
Features and bene ts surface reduces hydraulic friction and increases
Anti -corrosive, UPVC being is inert to pump efficiency.
chemicals found in soil and water
Different slot widths are available to satisfy the
e casing pipes are produced under strict requirements of different underground rock
control of pipe wall thickness and diameter; this formations. We offer this in 0.75mm, to 1.0mm
ensures thread uniformity and therefore thickness the light and easy to handle casing pipes
reliability continuous ribs increase permeability are economical to install and transport, hence the
by keeping gravel pack away from slot opening. pipes are made to customers' requirements, in 6
Higher permeability reduces draw down and meters, 4 meters and 3 meters.
results in saving in pumping energy. e smooth
and strong joins which allow removal and re-
jointing several times without causing any
damage to the thread pitch.
Meeting to din 4925 standards means that the
pipes are made to highest quality. e distinctive
Contributors’ Details
1. WTPI (Water Technology Plastic Industries)
Physical Address: 50 Kya Sands Road, Kya Sands, Johannesburg, South Africa
Call [phone] or [phone]
www.wtpi.co.za
blue colour of the pipes is recognised as borehole
casings.
reading of the pipe ends is done professionally
on precision equipment by our exp er t
production team.
July - August 2017
2. Roscoe Moss Company
Los Angeles Office, 4360 Worth Street, Los Angeles, CA 90063 USA
Phone: [phone]
3. Imperial Plastics LTD
Physical Address: Plot No. 456A Kafue Road, Shimabala, Lusaka, Zambia
Tel: [phone] | 84 5544
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