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Steel is an alloy consisting of iron and carbon in which the carbon content
does not exceed 1.7 per cent. Steel is obtained from cast iron. Steel is hard and
malleable. There are different kinds of steel, such as cast steel and forged steel.
Alloyed Steel (or Special Steel) is steel to which elements not present in
carbon steel have been added, or in which the content of manganese or silicon
is increased above that in carbon steel. This kind of steel is widely used in
building.
Stainless Steel is corrosion resistant steel of a wide variety of composi-
tions but always containing a high percentage of chromium (8-25%). Stainless
steel is used for cutlery, furnace parts, chemical plant equipment, valves, ball-
bearings,etc. Non-ferrous metals
Some of the characteristics of non-ferrous metals are: high electric and
heat conductivity, high corrosion resistance, non-magnetic qualities, light
weight and easiness to fabrication.
Aluminium is the oldest and best known light metal. An aluminium alloy
containing about 8 per cent of copper is stronger than pure aluminium but it
possesses less ductility.
Aluminium is a white silvery metal. It does not rust in the air. Aluminium
like copper is a soft metal. That is why it is used only when alloyed with other
metals. Aluminium alloys are liable to corrosion, particularly by salt water, or
in salty atmosphere.
Copper is found in nature in the form of ores but it is sometimes found in
pure state. Pure copper is of reddish colour and it has corrosion resistant quali-
ties. Copper is the best conductor of electricity. There are many different alloys
with copper. An alloy of copper and tin is called bronze.
Gas pool heater plumbing
If you want to install a swimming pool there are many possibilities avail-
able today when talking about materials, shape and size. On the other hand, an-
other very important choice you do need to make is what type of pool heater to
install. The most common choice stands in gas and propane pool heaters
. They
will work on natural gas if your home has it or on propane tanks
that can be
mounted below or above ground.
Today’s gas pool heaters are highly efficient and will only consume as
much gas as you want them to. They are controlled with the use of a thermostat
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