Page 25 - Parker - The Handbook of Hydraulic Filtration

Filter Element Life

Filter Element Life Profile
Every filter element has a characteris- instrumentation for recording the Then, the quantity, size, shape, and
tic pressure differential versus contam- change in the pressure loss across the arrangement of the pores in the filter
inant loading relationship. This rela- filter element is seldom available. Most element determine the characteristic
tionship can be defined as the “filter machinery users and designers simply life profile. Filter elements that are
element life profile.” The actual life specify filter housings with differential manufactured from cellulose media,
profile is obviously affected by the sys- pressure indicators to signal when the single layer fiberglass media and multi-
tem operating conditions. Variations in filter element should be changed. layer fiberglass media all have a very
the system flow rate and fluid viscosity different life profile. The graphic
affect the clean pressure differential The Multipass Test data can be used comparison of the three most common
across the filter element and have a to develop the pressure differential media configurations clearly shows
well-defined effect upon the actual versus contaminant loading relation- the life advantage of the multilayer
element life profile. ship, defined as the filter element life fiberglass media element.
profile. As previously mentioned, such
The filter element life profile is very
operating conditions as flow rate and
difficult to evaluate in actual operating
fluid viscosity affect the life profile for
systems. The system operating versus
a filter element. Life profile compar-
idle time, the duty cycle and the
isons can only be made when these
changing ambient contaminant condi-
operating conditions are identical and
tions all affect the life profile of the
the filter elements are the same size.
filter element. In addition, precise

Element Types Life Comparison

100
Cellulose Single Layer Multilayer 6
90
Fiberglass
Fiberglass
DIFFERENTIAL PRESSURE (PSI) 60 4 DIFFERENTIAL PRESSURE (bar)
80
5
70

50
3
40
30
2
20
10

0
0 5 10 15 20 25 30 35 40 45 50 1
CAPACITY (GRAMS)

23