INTRODUCTION The Copper Pipe is a periodical publication to provide
information on copper pipes utilized for different purposes,
such as water, gas, refrigeration and heating.
This Bulletin will also collect the experiences of other Promotion
Centers of Copper around the world, considering that in almost
all countries copper pipelines are the most convenient solution
which is determined through a cost-benefit analysis throughout
time.
A
BIT OF HISTORY
Since
the end of the fifth millennium before Christ, populations
of the Middle East used copper in pure state or linked
initially to lead and later, to a tin alloy known as bronze,
to manufacture weapons, coins and home utensils. The importance
of the use of copper in the history of humanity during
this stage is reflected in its name: The Bronze Era.
In ancient times, the most important copper mining was located
in the isle of Cyprus, where the Latin word Cuprum comes from
and which gave origin to the chemical symbol Cu currently used
in almost all languages to refer to this valuable metal.
It has been possible to confirm that in the year 2700 AC copper
pipes were already used in Egypt to transport drinking water
and drainage flows. These pipes are exhibited in the British
Museum of London.
Copper pipe used in Egypt
During the Roman Empire, copper pipes were utilized to transport
water, which has been proven by the excellent conditions of
the pipelines found in the excavations carried out in Pompey.
Currently, copper is utilized in aerospace technology. For example,
the propellers' combustion chamber of the spacecraft Ariane
5 has an interior cover made of a copper, silver and zirconium
alloy.
Copper alloys are standard materials in the portable structures
of satellites. Solar cells are placed in the solar energy collection
paddles, which include copper, among other materials.
The chemical industry values the outstanding resistance to corrosion
and thermal conductivity of this material. Considering these
reasons and due to the strict demands on hygiene, the food and
beverages industries are using copper more frequently.
PIPES
AND PIPESLINES
A
pipe is a product with an interior cavity, with different shapes
that can be round, square or any other as required. It has a
continuous periphery and is utilized in plumbing and mechanical
systems for the transportation of fluids and gasses.
Due to the proper characteristics of this metal, copper pipes
are lightweight, strong, adaptable and highly resistant to corrosion.
For this reason, they have a perfect behaviour when used in
homes, buildings, condominiums, offices, and commercial and
industrial facilities.
The concept of pipes should be differentiated from that of pipelines,
which are pipes with standardized dimensions. For example, according
to Norm ASTM (American Society for Testing and Materials), the
exterior diameter of a pipeline is the same as the nominal diameter
plus 1/8.
THE
PRODUCTIVE PROCESS OF THE COPPER PIPE
Nowadays, copper is widely utilized in different forms, such
as wires, bars, profiles, pipes and sheets. The characteristics
of these products come from metallic copper and the metallurgical
processes used to produce it.
The metal (generally a mixture of refined copper and controlled
quality scrap metal) is melted in an oven. Ingots -known as
billets-are obtained from a taping of molten copper and have
cylindrical shape with dimensions that usually measure 300-mm
diameter and 8 m long, and an approximate weight of 5 metric
tons.
These metallic blocks are used to manufacture pipes without
seams through a series of plastic deformations.
The stages of the production process of copper pipes are the
following:
Cut:
Billets are cut into pieces of nearly 700 mm long, considering
the factory's production capacity installations.
Heating:
Following, the billet is heated in a tunnel oven at temperatures
between 800° and 900°C. In this stage, the metal reaches
a higher degree of plastic deformation capacity through
which pressure is reduced as required for the next transformation
processes.
Extrusion:
In this stage, a piece or bulk pipe with a big diameter
and very thick wall is obtained at first. Actually, the
extruder is a press in which the billet -previously heated-is
forced through a calibrated matrix. Pressure is exerted
through a piston, which has a mandrel to perforate the billet.
This process is made at high temperatures, due to which
subsequent processes are carried out under controlled atmospheres
with accelerated cooling in order to prevent superficial
oxidation of the bulk pipe.
Lamination:
This hard-process consists in taking the bulk pipe through
two cylinders which revolve in opposite directions. Additionally
to the rotatory impulse, the two cylinders have a longitudinal
swinging, while the bulk pipe -to which a mandrel has been
embedded-advances helically. Thus, a thickness reduction
in the pipe wall is obtained, maintaining the section as
a perfect circle. The hard-lamination process produces high
hardness pipes, also known as hard quench.
Wiredrawing:
The consecutive reduction of diameter to obtain diverse
commercial products is carried out through a hard-process
known as wiredrawing. This process consists in stretching
the pipe through several external matrixes and one internal
gage known as floating mandrel. The industrial process is
carried out in a machine known as "Bull Block", where the
end of the pipe is tightened with a clamp installed onto
a rotatory cylinder that produces the tension.
Annealing:
The hard-plastic deformation causes the metal's hardening
and loss of plasticity. The consecutive wiredrawings increase
hardening and exposes the pipe to higher risks of breaking.
Therefore, a thermal process known as annealing is utilized
to obtain the crystallization of copper to recover its plasticity
characteristics.
Finishing:
An annealed pipe is obtained at the end of the production
process, which is presented in high quality coils. It is
possible to apply an external covering for protection or
isolation to these pipes, which will depend on the several
uses, or to make a very smooth interior finishing for special
applications.
Quality
Control: Once manufactured, the pipe is subject to trials
to detect imperfections among which, the electromagnetic
induction with Foucault currents is usually used to detect
cracks and other imperfections inside the pipe's wall.
Packaging: Copper annealed or soft quench pipes are
presented in coils, which are carefully packaged to prevent
deformations caused by movements. Hard-laminated pipes of
hard quench are presented in strips, usually 6 m long, which
are packaged in bundles for transportation to locations
for its use. Taking into account that copper pipes do not
experience aging due to the action of ultraviolet rays,
ozone or other chemical and physical agents, special conditions
for storage and packaging are not required.
USES
OF COPPER PIPESLINES
Construction
Transportation
of drinking water.
Drainpipes.
Distribution of cold and hot water.
Home and industrial outflows.
Rainwater drainpipes.
Drain
and ventilation of sewer systems.
Transportation of flammable gasses.
Hot water or steam heating systems for homes.
Solar collectors.
Rigid electricity conductors.
Conduit pipes for electric conductors.
Decorative and hardware store uses.
Structural uses.
Hot
water systems in
apartment buildings
Mechanical
or industrial
Air conditioning and cooling.
Transportation
of liquid fuels.
Transportation of compressed air.
Coils of heat pumps.
Heat interchanger pipes.
Condenser pipes.
Transportation of non-flammable gasses.
Transportation of medicinal gasses.
Steam pipes.
Transportation of industrial fluids.
Transportation of foodstuff fluids (beer, milk, etc.).
Boilers.
Heat pipes.
Waveguides.
Heat
interchanger
Transportation
Brake pipelines.
Fuel conductors.
Radiators.
Air conditioner.
Radiators
with copper alloy pipes
QUALITY
AND ADVANTAGE OF COPPER PIPELINES
Durability
Withstands the toughest pressure and temperature conditions.
Does not diminish with exposure to light.
Resistance to the possible attacks of the fluids it transports.
Has long useful life, at least so long as the building it
has been installed, thus exceeding the most demanding test:
time.
Installation
Simple, quick and clean.
Easily shaped due to its flexibility and adaptability, allowing
adjustment to any structure and available space.
Its low weight per lineal meter of pipeline makes transportation
cheaper and easier operation.
Allows installations without using great number of joints
and elbows
Diversity:
Copper is malleable and
ductile. It allows a great variety of couplings, bends, joints,
siphons, etc.
Ideal for serial prefabrication.
The equal exterior diameter of the copper pipe allows transporting
greater volumes of flows due to its resistance to tension
and to the fact that the thickness of its wall may be lower.
Efficiency:
The copper pipe may be bended without
decreasing the water flow, guaranteeing a minimum drop of pressure
due to interior smooth walls.
High surface quality: copper pipes have a low loss of load
(opposition to the path of fluids).
Minimum expansion and high resistance when exposed to greater
changes in temperature.
Allows exterior assemblies due to high resistance to corrosion
and impermeability, which prevents the path of ultraviolet
rays.
Resistance
Resistant to corrosion and in the short run, does not tend
to form large coatings of oxide or other compounds with
drinking water that may obstruct the pipes.
Resistant to the attack of materials used in construction
(cement, gypsum, plaster, etc.)
Impermeability to gasses and oxygen.
Withstands extended contact with the most utilized soils
in construction.
Resistant to the highest pressures and temperatures over
200°C and is a non-flammable material.
Great flexibility, allowing deformation when pressure increases
but without breaking.
Resistant to the attack of other external agents, such as
rodents.
Safety
It is a very safe material in case of fire: flames are not
expanded, does not decompose with heat producing highly
poisonous gasses, is not consumed and do not stop transporting
water due to the action of the flames.
Due to its permeability, welded copper pipes are completely
impenetrable and permeable to harmful chemical products
to the surrounding environment.
