Page 26 - Parker - The Handbook of Hydraulic Filtration
P. 26
Filter Housing Selection
Filtration Fact Filter Housings Pressure Ratings
The filter housing is the pressure vessel Location of the filter in the circuit is the
Always use an element which contains the filter element. It primary determinant of pressure rating.
usually consists of two or more sub- Filter housings are generically
condition indicator with any
assemblies, such as a head (or cover) designed for three locations in a cir-
filter, especially those that and a bowl to allow access to the filter cuit: suction, pressure, or return lines.
do not have a bypass valve. element. The housing has inlet and out- One characteristic of these locations is
let ports allowing it to be installed into a their maximum operating pressures.
fluid system. Additional housing features Suction and return line filters are
Filtration Fact may include mounting holes, bypass generally designed for lower pressures
valves and element condition indicators. up to 500 psi (34 bar). Pressure filter
An element loading with
contaminant will continue Visual/electrical element
condition indicator
to increase in pressure
differential until either: Bypass valve Assembly
• The element is replaced.
• The bypass valve opens.
• The element fails.
Inlet port
Pressure housing
Filter element
Drain port
The primary concerns in the housing locations may require ratings from 1500
selection process include mounting psi to 6000 psi (103 bar to 414 bar).
methods, porting options, indicator It is essential to analyze the circuit for
options, and pressure rating. All, except
frequent pressure spikes as well as
the pressure rating, depend on the phys- steady state conditions. Some housings
ical system design and the preferences
have restrictive or lower fatigue
of the designer. Pressure rating of the pressure ratings. In circuits with fre-
housing is far less arbitrary. This should
quent high pressure spikes, another
be determined before the housing style type housing may be required to
is selected.
prevent fatigue related failures.
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