Transfer Of Vibrations From The Installation; Discharge Pipe; Unfavourable Environmental Conditions; Leaks Caused By Foreign Bodies - Leser 612 Instrucciones De Servicio

•
It is possible to drill a drain hole later at
the place intended for this purpose.
Caution: swarf can cause damage which
may lead to leaks or to the failure of
safety valves.
•
Drainage pipes must be installed sloping
downwards; these pipes must have no
restrictions such
diameters. There
unobstructed view of the drain outlet; any
risks resulting from leaking medium must
be prevented.
condensation traps, drip container, filters,
etc.)
•
Unused drainage holes must be closed.

12.8 Transfer of vibrations from the installation

Any vibrations which might be transferred to
the safety valve must be prevented. If this is
not possible the safety valve must be
decoupled from the installation, e.g., via
bellows, pipe bends, ...
Pressure variations or surges in the medium
also may lead to dangerous vibrations of the
safety valve. This also has to be prevented.
If the transfer of vibrations cannot be
prevented, damping systems can be built in,
e.g., o-ring dampers.

12.9 Discharge pipe

When a safety valve blows off, in addition to
the general hazards from the medium, the
following hazards have to be expected (refer
to section 2):
•
High flow rates
•
High temperatures
•
Noise emissions
In this context the following points should be
noted:
•
For steam or gases the blow-off pipe
should point upwards in order to allow
blowing off without danger.
•
For liquids the blow-off pipe should point
downwards so that the medium can
completely drain out of the blow-off
chamber.
•
The outlet flange of safety valves or blow-
off pipes must be directed so that no
danger is caused by the medium blowing
off. The following options are available:
Blowing off into a container
-
Safety valve and blowing-off pipes
-
without direct access
Design with silencer.
-

12.10 Unfavourable environmental conditions

as locally reduced
must be an
(e.g., by fitting

12.11 Leaks caused by foreign bodies

12.12 Protection during storage and transport

All LESER safety valves which may corrode
are coated with a protective coating during
manufacture which protects the safety valve
during storage and transport. In corrosive
environments a further corrosion protection is
required (refer to section 12.13). For extreme
conditions, LESER recommends stainless
steel safety valves. The
loading system must not be given a protective
coating!
External media (e.g., rain water or dirt/dust)
must not enter the blowing-off pipe or come in
contact with functional components (e.g.,
guides with open bonnets) have to be
avoided. By analogy, the statements made in
section 7 apply.
Simple preventive measures are possible:
•
Protection of the blow-off chamber from
extraneous media and dirt
•
Protection of the parts important to
operating from external media and dirt.
Foreign bodies must not remain in the
installation (e.g., welding beads, sealing
material such as hemp tape, PTFE tape,
screws, etc.). One option for avoiding foreign
bodies in the system is to flush it before
commissioning.
If leaks are caused by contamination between
the sealing surfaces, the safety valve can be
vented to clean the surfaces. If this does not
stop the leak, one of the sealing surfaces is
probably damaged. In this case the safety
valve has to be serviced.
All protective devices for transport and
handling have to be removed before installing
the safety valve.
After installation, the protection for the lever
must be removed from the bonnet as
otherwise the safety valve cannot be vented.
The lever must move freely, i.e. it must be in
its initial position and the coupling at the
spindle must not be connected to the lever.
In the case of lever safety valves, the wooden
wedge, which protects the sealing surfaces
from damage during transport, has to be
removed.
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