| A well planned compressed air system is
vital to efficient overall operation in industry.
Improper tool operation, higher costs per unit of compressed
air and reduced component life are but a few of the
many problems created by an inefficient system. This
in turn, results in the overall loss of millions of industry
dollars every year.
Five key components
to an efficient compressed air system are the dryer, filter,
regulator, lubricator and mechanical drain. When properly
sized, installed and maintained, these units play a critical
role in achieving optimum performance in the system.
As a rule, no more than two devices should be serviced
by a single dryer, filter, regulator or lubricators.
DESICCANT AIR DRYERS
The presence of water or moisture in an
air line system is undesirable because of the damage it
can do to pneumatic tools, cylinders, valves and other
components. When air is compressed, both its temperature
and capacity to hold moisture are increased. As
the air moves downstream and cools to the "dew point",
the moisture condenses into drops of water (liquid condensate).
Although much of this liquid can be removed through the
use of filters, drip legs and drain traps, water vapor
and aerosols will remain in the line.
The most reliable and cost efficient method
of removing this residual vapor and aerosol is with desiccant
air dryer. These units are especially effective for protecting
laboratory instrumentation, spray painting operations
and air lines that are exposed to freezing conditions.
FILTERS
It is inevitable that impurities will
make their way into the air distribution lines in any
system. Pipe scale, rust, moisture, compressor oil,
pipe compound and dirt are some of the contaminants that
can damage valve parts and other close fitting parts of
downstream devices.
A filter will remove all foreign matter
and allow clean dry air to flow freely. It should
be installed in the line upstream from all working devices
and in such a way that it cannot be bypassed to
avoid damage to those devices.
The filter capacity should be large enough
to handle the required flow of air. In order to
properly size a filter for a particular application, the
maximum allowable pressure drop that can be caused
by the filter should be established.
REGULATORS
Pneumatic equipment is designed to operated
properly at a certain pressure. Although most equipment
will run at pressure higher than recommended, the excess
force, torque and wear can shorten the equipment's life
and waste compressed air. A regulator will provide
a constant set flow of air pressure at its outlet, thus
assuring optimum operation and life of the downstream
equipment.
The size of a regulator is determined
by the downstream flow and pressure requirements.
While an undersized regulator will not be able to provide
the required air pressure during
maximum flow conditions, an oversized regulator will be
more costly than necessary to do the job.
LUBRICATORS
Most moving parts require some form of
lubrication The high costs of inefficiently running equipment
and repair expenses make the addition of an air line lubricator
an economical practice. Lubricators store oil and inject
a preset amount of oil mist, or fog, into the air stream
which is then delivered to the downstream device.
Special attention should be paid to the
compatibility of the lubricants used in the system and
the materials in the lubricator, especially where plastic
reservoirs (bowls) are concerned.
MECHANICAL CONDENSATE DRAINS
Condensation accumulated from compressor
tanks, filters, drop legs, after coolers, dryers or other
devices must be drained off so it does not flood the system.
As a means of eliminating the chore of manually draining
this liquid build-up from numerous collection points,
a mechanical condensate drain will do it automatically
while minimizing air loss. As the liquid level inside
the collection bowl rises, a float is lifted and opens
the drain valve The liquid accumulated inside the
bowl is then discharged at
line pressure.
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