Leser 4401 Instrucciones De Servicio página 13

Operating Instructions
must be used so that no excessively high
forces or mechanical stress may arise.
Torques must be adhered to. Manufacturer
specifications must be observed. Safety
valves – above all the sealing surfaces –
must be protected against impacts during
the installation.
As a rule, safety valves must be installed
in an upright position. Exceptions are only
permissible if other installation positions
are mentioned in the product-related tech-
nical documents. A horizontal installation
position must be agreed on by the opera-
tor, manufacturer and an expert.
LESER is not
welding activities on connection ends.
The properties after welding must satisfy
the product's scope of application. This
means that the welding activities must be
performed so that:
• orifice areas and wall thicknesses are
not reduced,
• the interpass temperature does not
exceed 50 °C.
Annealing processes may be required to
treat the material after welding. The fol-
lowing requirements apply: The annealing
temperature must be below 630 °C and
the annealing time must not exceed 40
minutes. Restrict the heat input during the
annealing process to the weld seam's heat-
affected zones to prevent the entire valve
from heating. The temperature on the bon-
net's flange must not exceed 150 °C for the
entire annealing process. This can be en-
responsible for
sured by cooling the entire bonnet.
The prescribed flow direction according to
the arrow on the body must be observed.
Safety valves must be installed in such a
way that dynamic vibrations in the system
cannot be transmitted to the safety valves.
If the system is not vibration free, then
bellows, O-rings or U-shaped expansion
pipes are suitable for decoupling the safety
valves from the system.
Safety valves with cast support brackets
must be fastened in the system. The sup-
port brackets absorb the reaction forces.
Adequately dimensioned gaskets must
be used on the connections of the safety
valves. Sealants or parts thereof must not
restrict the flow areas and must not be
able to detach and enter the flow space.
The connections must be configured in ac-
cordance with the specifications in the rule
groups.
The supply lines and blow-off lines of the
safety valve must be dimensioned ad-
equately and adapted to the local operat-
ing conditions. The diameters of the inlet
and outlet pipelines must not be smaller
than the respective diameters at the safety
valve. It might be necessary to use heating
systems.
The maximum occurring back pressure,
the maximum inlet pressure loss and the
temperature must be taken into account.
The unhindered and risk-free flow-off of
the medium through the outlet must always
be guaranteed. Safety valves may not be
rendered ineffective by blocking devices.
EN
12