E70500 pages
Filter
Clogging Indicators
1.1tGeneral
HYDAC clogging indicators are
designed to indicate visually and/or
electrically when the filter elements
must be cleaned or changed. The
operational safety of a system and
efficient utilisation of a filter element
can only be guaranteed if clogging
indicators are used.
Depending on the type of filter,
vacuum, return line or differential
pressure clogging indicators are used.
1.2tSeals
NBR (= Perbunan) or V (= Viton)
1.3 INSTALLATION
Some users install filters without
clogging indicators and prefer instead
to replace or clean the elements
according to a specified time schedule
or according to a set number of
operating hours. However, this
involves some risk.
Fitting a clogging indicator has two
main advantages:
t operator no longer has to estimate
The
when the element is clogged.
t unnecessary costs of changing
The
the element too early are avoided.
All standard filters can be fitted with
a clogging indicator at any time, by
simply screwing it in.
1.4tDESIGN
Return line indicators
These are used for return line and
suction filters. In return line filters they
react to the increasing static pressure
before the filter element, and in suction
filters to the decreasing pressure after
the filter element, which is caused by
increasing contamination.
1.4 SPECIAL INDICATORS
Mobile indicators
These indicators have been developed
for special applications and are fitted
with AMP, Deutsch and Junior Power
Timer plugs.
ATEX indicators
These indicators are used in
potentially explosive locations and
are subject to the ATEX Equipment
Directive 94/9/EC and the ATEX
Operator Directive 1999/92/EC.
UL and CSA indicators
Indicators which are exported to
the USA and Canada often require
classification according to current UL
and CSA standards. The UL and CSA
symbols are found on many products,
particularly in the field of electrical
engineering.
Differential pressure indicators
These are used for all inline filters
and react to the increasing pressure
differential caused by increasing
contamination of the filter element.
The most simple installation of the
differential clogging indicator:
G ½" cavity (according to HYDAC
works standard HN 28-22)
The differential pressure indicator type
V02 is piped up separately.
Contaminated
side
clean side
1.6 TABLE OF CONTENTS
Contents
Quick selection table:
by indicator type
Quick selection table:
by filter type
Standard indicators
Vacuum
Return line
Differential pressure
Indicator VL for
Condition Monitoring
Mobile indicators
Return line
Differential pressure
ATEX indicators
Return line
Differential pressure
UL/CSA indicators
Differential pressure
Return line
Model code - Standard
Adapters
DESINA Specification
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E 7.050.13/03.12
1.tTECHNiCAL
SPECIFICATIONS
63
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