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Bundesmann Water Repellcy Tester:
The “ASIAN�
Bundesmann Apparatus consists of a steel structure with
specimens is rotated at a specified speed in this tank about a
vertical axis with the help on an Electric motor and worm reduction
gearbox placed underneath the tank. Impinging of water jets coming
from nuzzles on 304 Screws fitted on an aluminium plate produces the
shower. The nozzles are fitted on aluminum blocks, which are in turn
connected to a closed piping system. Water is supplied to piping
system through an electric pump. A control valve And a pressure gauge
are also provided to regulate and indicate pressure in the pipeline.
A guard is provided to contain splash produced. Water not impinging
on the screws is also collected in this tray and drained away.
This shower arrangement is
mounted on the top of the structure to give the specified drop
height. A hinged tray which can be swung during the testing is also
provided to shield the assembly from shower before and after the
test. An arrangement to collect water circulation tank and
re-circulate it with the help of the pump is also provided.
The
cup assembly consists of four aluminum cups with their axis tilted
outward at 10º to
15º to the vertical mounted on an aluminum base. Specimen
holding ring made of aluminum hold the specimen on-to the cups with
the help have screwed clamps. Each cup four-wiper blades set
perpendicular to each other in the form of a cross. The wiper blades
are made of stainless steel and are tapered down away from the
center. The abrading face of each blade is cylindrical in shape. The
wiper assembly presses against the lower surface of the test specimen
with the help of a spring. Arrangement is also made to make the wiper
blade assembly oscillate through an angle of 100º four times in
every one revolution of the cup assembly. Gunmetal drain fitted to
each cup for draining out the water collected in them. The cup
assembly can be easily taken out to facilitate mounting of specimens
and draining of water collected in the cups for determination of
amount of water that has penetrated through the specimens. Specimens
loading disk is also provided with the equipment to depress wipers to
rim level while mounting the specimen.
Technical Specifications:
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Diameter
of test specimen:
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140
mm
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Diameter
of test opening
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100mm
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Rate
of collection of water in each cup
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65+
3ml/minute
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Distance
between nozzle tip and specimen centre
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150
cm
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Speed
of rotation of cup assembly
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5rpm
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Distance
between center of specimen and vertical
Axis
of rotation of cup assembly
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105
+10 mm
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Thickness
of wiper blades
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5.08
to5.13mm
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Radius
of contact edges of wipers
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6.35mm
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Load
exerted on specimen by wipers
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400
+50mg
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