Brochure

Bulletin 40-10 – Page 7
Liquid Line
Ratings and Selection Recommendations
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GENERAL
The selection of a filter-drier for a given
application involves such technical
factors as: the amount of moisture to
be expected in a system — operating
temperatures — amount of foreign
matter present — allowable pressure
drop through the filter-drier — its ability
to retain both liquid and solid contami-
nants, and bursting pressure. Proper
evaluation of these factors is necessary for
optimum service and economy. As an aid,
the important factors to be considered for
selection purposes are discussed briefly
in the following sections.
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STANDARD RATINGS
ashrae-ari
The American Society of Heating,
Refrigerating and Air Conditioning
Engineers Standard 63, “Methods of
Testing Liquid Line Refrigerant Driers,”
sets up a test procedure to follow for
determining the water capacity and
refrigerant flow capacity under certain
conditions. The Air Conditioning and
Refrigeration Institute subsequently
issued ARI Standard 710, which specifies
the rating conditions for water capacity,
refrigerant flow capacity, and safety
requirements.
This Standard is intended to provide
comparison points only. It is a basis for
drier evaluation at the specified rating
conditions, but does not attempt to
govern the performance of a drier over
the entire range of possible applications.
It serves only to compare driers on their
ratings for water capacity, refrigerant flow
capacity, and safety requirements.
Water capacity
Water capacity is the amount of water
(in drops or grams) that a drier will hold
at the standard temperatures and equi-
librium point dryness (EPD) specified.
Twenty drops equal one gram, equal one
milliliter or one cubic centimeter.
Equilibrium Point Dryness (EPD) — is
used to define the lowest possible water
content in liquid refrigerant attainable
by a filter-drier at a specific temperature
after it has collected a specific quantity of
water after equilibrium has been reached
between the water in the refrigerant and
the water in the drier. Equilibrium point
dryness is expressed in parts per million
(ppm) by weight.
refrigerant floW capacity
The maximum flow of liquid refrigerant
(in tons) that a drier will pass at a 1
psi/0.07 bar pressure drop is the refrig-
erant flow capacity. The “ton” ratings are
based on 86°F/30°C liquid temperature
and refrigerant flows of…
4.0 lbs. per minute per ton for R-12
3.1 lbs. per minute per ton for R-134a
2.9 lbs. per minute per ton for R-22
3.9 lbs. per minute per ton for R-404A
2.9 lbs. per minute per ton for R-407C
2.8 lbs. per minute per ton for R-410A
4.4 lbs. per minute per ton for R-502
4.1 lbs. per minute per ton for R-507
safety
Safety is based on drier shell bursting
pressure. All liquid line driers manu-
factured under ARI Standard 710 must
meet the requirements of Underwriters’
Laboratories, Inc., Standard 207,
“Refrigerant Containing Components and
Accessories, Nonelectrical.”
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SELECTION
When selecting a filter-drier the following
should be considered:
Water capacity
and refrigerant floW
Water capacity and refrigerant flow
comparisons can be made on the basis of
ARI Standard data supplied by the manu-
facturer. However, it should be remem-
bered that flow ratings are based on the
ideal situation of a completely clean
system. Flow is reduced as dirt accumu-
lates on the filtering surface.
filtration
Filtration characteristics of a filter-drier
are not readily defined or evaluated since
laboratory tests cannot reproduce the
range of conditions and contaminants
seen in an actual system. The ability
to filter and hold foreign matter varies
with the brand and type of filter-drier.
The simplest guide to follow is that filter
capacity is proportional to filtering area.
In the tables that follow, the filtering areas
of all Catch-All Filter-Driers are tabu-
lated. Filters should be selected with an
adequate reserve capacity to allow for the
contamination found in most systems.
acid removal
Acid Removal is also difficult to measure.
There are no standard ratings to follow.
However, both laboratory and field tests
have demonstrated that the Catch-All
core has superior acid removal ability —
many times the acid capacity of competi-
tive filter-driers developed for today’s
systems.
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SPORLAN
RECOMMENDATIONS
Sporlan’s Selection Recommendations
are based on the technical data currently
available and more than 60 years of field
experience with molded porous core
filter-driers. Satisfactory results will be
obtained with the sizes recommended
for all normal refrigeration systems. We
have considered the difference in require-
ments for air conditioning and refrigera-
tion applications. Recommendations
for these categories are made on pages
12 through 16 and pages 25 through 28.
Recommendations for suction line use
of filter-driers are in Form 40-109. Form
40-109 is a quick reference guide for
suction line filter-drier selection.
Drier manufacturers establish ratings
for their product, but…the final selec-
tion of the correct drier should be based
on the conditions expected for each
job. Consideration should be given
to providing extra water capacity and
filtering area within economical limits.