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DMI INTERNATIONAL,
USA
F
or over a century, DMI International has specialised
in pipe bending equipment, and its equipment
has been used in over 70 countries. The company
designs, engineers, and manufactures its equipment
in its own state-of-the-art facility. DMI International
prides itself on designing and building equipment that
performs in peak condition in even the harshest and most
demanding environments.
The company’s pipe bending machine is designed to
a maximum width of 12 ft 6 in. width, which keeps the
unit within the road width limits and does not require
special permitting in some countries, thus allowing the
bender to be moved between different jobsites without
unnecessary delays in permit acquisition. This narrow
footprint, combined with the 121 000 lb total unit weight,
is designed to increase agility and the bending crew’s
efficiency, helping projects to come in on time and on
budget.
One of the primary causes of failures in hydraulic
systems is contamination. Most pipe bending machines
utilise either a return line or a pressure filtration system.
DMI International has incorporated both in order to
combat the fine silt dust found on the right-of-way
(ROW), and the multiple points of ingression in a hydraulic
system used in this environment. The company has also
reduced ingression points by redesigning the sealing
system on the hydraulic cylinders and reservoir breathing
filters, resulting in a smooth operation and a longer
service life for the equipment.
The machine utilises a 250 hp CAT/Perkins engine.
Operating at 2200 rpm, this power unit provides more
than sufficient torque to drive the unit through the most
difficult bends. Equipped with a 20 000 lb pulling force
winch with a freewheeling
drum and optional controls
for driving a hydraulic mandrel,
this unit is outfitted to exceed
the rigorous demands of bending
pipe on the ROW.
This machine is designed with
a hydraulic remote control system,
which keeps high pressure and high
flow hydraulic lines away from the
operator. It also features dual pressure
hydraulic controls for the pin-up and
bending circuits, thus allowing the operator
to establish the required bending forces and
greatly reducing the possibility of wrinkling the
pipe by overbending, or by bending on the back
of the die.
Another feature that lends itself to its improved
bending performance is the ‘high flow/low flow’
pump configuration. The pump supplies maximum
flow to the circuit during both the retraction and
extension mode operation of the bending process. During
the bending mode operation, the pump displacement is
reduced, thus providing a reduced flow to the circuit. The
benefit of this system is the reduction of the time spent
retracting and positioning the cylinders, and providing
greater precision when entering the bending zone of the
pipe.
Utilising separate pressure control zones provides
the operator with improved capabilities and produces
higher quality bends. The ‘high/low’ system can reduce
operator lag time, increasing the efficiency of the
bending crew without sacrificing bending precision.
36 - 48 in.
pipe bending machine from DMI International.
Heavy equipment review
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