Leser 411 Instructions De Service page 28

connected to the safety valve via a coupling. The
coupling must not be blocked by objects. It is
neither necessary nor permitted to apply a
protective coating to the actuator.
The pressure tapping lines must not be shut off. If
there are shut-off devices they have to be
designed in such a way that they cannot be
closed, e.g., by means of locking bars or seals.
LESER control units are equipped with a shut-off
device for maintenance purposes. They are
E
secured against shutting-off by means of a
locking bar. This locking bar must not be
removed.
The pressure switches are wire-locked and
sealed. This seal indicates that the setting has
not been changed. It is not permitted to
manipulate the pressure switches (e.g., by
opening the seal and modifying the adjustment or
by opening the switching contacts, ...)!
If a test gag is used during pressure testing of the
installation it must be removed after the test.
16 Combined Safety Valve and Bursting Disc
The type test approval of the combination of
bursting discs of a certain manufacturer with
LESER safety valve ensures that both the
functional and performance requirements are
met. If you require information on the tested
combinations, please contact LESER.
Combinations of LESER safety valves and
bursting discs of other manufacturers are per-
missible, if they meet the safety requirements.
This shall be certified for each individual case.
The following points should be noted in
particular:
• Operating instructions for the bursting disc.
• Safety valves must not lose their function by
placing the upstream bursting disc.
• The space between the rear side of the bursting
disc and safety valve inlet should be monitored.
• The bursting disc should be designed in a way
that it cannot be installed incorrectly.
• The bursting disc has to open free of
fragments. Bursting disc components must not
enter the inlet connecting pieces of the safety
valve thus impairing the function.
• Sets of rules with reference to bursting discs
(AD 2000-Merkblatt A1, ASME, ...)
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17 Unexpected conditions
Not all errors can be prevented entirely.
However, their consequences must be estimated
and reduced by:
• A risk analysis for the complete installation
• An estimate of the risk and potential damage
• Instructions about the measures to be taken in
the case of malfunctioning
• Staff training at the manufacturer's and at the
operator's
• Protective measures for people and for the
environment.
18 Product overview
For the product overview please refer to the
"Declaration of conformity".
19 Assembly instructions
In addition to the Operating Instructions there is a
number of type-specific assembly instructions,
which are listed in the "Request form LESER
Assembly Instructions".
In detail the type-specific assembly instructions
have to be observed.
20 Disclaimer
The manufacturer reserves the right to make
technical changes or improvements at any time.