Norgren Filter Contents - Manual (Page 3)

Filters
Littleton, CO USA Phone 303-794-2611 www.norgren.com ALE-Filter
Figure 1. (See “Rating Filter Elements and ISO
Standard 8573-1” in this section.
RECOMMENDED FILTRATION LEVELS.
Application
Typical Quality Classes
Oil Dirt
Air agitation 1 3
Air bearings 2 2
Air gauging 2 2
Air motors 4 4
Brick and glass machines 5 4
Cleaning of machine parts 3 4
Construction 4 5
Conveying, granular products 2 4
Conveying, powder products 1 3
Fluidics, power circuits 2 5
Fluidics, sensors 2 3
Foundry machines 4 5
Food and beverages 1 1
Hand operated air tools 5 5
Machine tools 5 4
Mining 5 5
Micro-electronics manufacture 1 1
Packaging and textile machines 5 3
Photographic film processing 1 2
Pneumatic cylinders 3 5
Pneumatic tools 5 4
Pneumatic tools (high speed) 4 3
Process control instruments 2 3
Paint spraying 1 1
Sand Blasting 4 5
Welding macines 5 5
General Workshop air 5 4
1.2.3 What Micron Ratings are Available?
The standard Norgren general purpose elements are
40 and 5 microns, with 40 microns being suitable
for most industrial applications. Certain industries
have 25 or 75 micron as a standard and some
product ranges have these options available.
For a given element size, the smaller the
micron rating the higher the pressure drop across
the filter. The service life between cleaning is also
less for the smaller micron filters, as small holes
plug more quickly than bigger holes.
1.2.4 How do Service Life Indicators Work?
The service life (pressure drop) indicator found on
top of coalescing or general purpose filters is green
when the filter is new. As a pressure differential
develops across the filter element with use, a spring
biased red outer sleeve is pushed up. When more
red is visible than green, then the pressure
differential across the element is in excess of 10 psi
(0.7 bar) and the element should be replaced.
1.2.5 When does the Carbon Pack Indicator Turn
Pink?
The white ring around the base of the vapor
removal carbon pack turns pink in the presence of
liquid oil. Therefore if the ring turns pink the
coalescing filter is passing liquid oil and needs
replacing. If this occurs soon after the filter has
been installed then it usually indicates a seal failure
in the coalescing filter. Remember that visual
detection is a not a substitute for scheduled
maintenance.
1.2.6 How Long does an Element Last?
This depends entirely on the quality of the inlet air.
If it is very poor the elements will need replacing
more frequently.
In general, air service equipment should
be maintained annually. Use, quality of air and
condition at examination may indicate adjustment
of the maintenance interval.
The following guidelines can be given:
General Purpose Replace/maintain annually. The
Filter:
element can lose 15% efficiency
each time it is cleaned. Elements
are low cost, so it is advisable to
replace them.
Coalescing: Evaluate after 12 months of
servicing. If the pressure drop
across the element exceeds 10
psig (0.7bar) then the element
requires changing.
Activated Carbon Should be changed every 1,000
Packs:
hours usage or when odor is
detected. The life depends
significantly on ambient
temperature.
1.3 PLASTIC BOWLS
Norgren transparent plastic bowls are made from
polycarbonate. Some competitors use other
materials such as Grilamid.
Both these materials are extremely resilient and have
an excellent safety record. However these
transparent plastics will degrade when subjected to
excessive heat, solvents and some chemicals, which
can lead to crazing and finally bowl failure.
Over the last few years metal bowls and
guarded plastic bowls have become increasingly
popular driven by the emergence of guidelines
recommending the use of guards.
Some organizations have their own internal
standards which call for guarded plastic or metal
bowl and the general market trend is away from
plastic bowls in the 1/2” or above port size units.
This trend is reflected in our latest Excelon 74 and
Olympian Plus product ranges. Plastic bowls remain
the most common option for 1/4” and smaller units.
Never use polycarbonate bowls at
conditions which exceed the maximum rated
pressure and temperature of 150 psig (10 bar) and
125°F (50°C).
Certain chemicals, common in some oils
and solvents, can attack polycarbonate and cause
the bowl to burst. If the compressor intake is located
in an area containing incompatible vapors, these
contaminants can be drawn into the compressor and
conveyed to the bowl in the compressed air. This
can result in bowl failure.
Synthetic compressor oils may be drawn in
from the compressor and can also result in bowl
failure.
If doubt exists as to the compatibility of
certain fluids with polycarbonate, please contact
Applications Engineering.
Metal bowls should be used where
temperatures exceed 125°F (50°C) and/or pressures
exceed 150 psig (10 bar), or when materials are
present which are incompatible with polycarbonate.
Maximum rated operating conditions for metal
bowls depend on the range; check APC-104.