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CAUTION:
For valves with welding ends, ensure that seals are not overheated during install-
ation / welding and that distortion of the housing is prevented. Also ensure that no
welding residue enters the valves. Any welding residue must be completely remo-
ved. Any weld seam heat treatment that is necessary is the responsibility of the
system manufacturer or operator.
5
Operating mode / Maintenance
The operating pressure of the plant is to be at least 15 % lower than the closing
pressure of the safety valve. In this way, the valve can satisfactorily close again after
blowing off. Depending on the installation situation, the closing pressure may deviate
from the set pressure by more than 10% or 15%.
ATTENTION:
When blowing off the safety valves, please note that gases can exhaust in high
velocity and with high temperature and excessive noise.
Safety valves with lifting device (version sGK)
In the case of safety valves with a lifting device it is recommended, and in certain
plant-specific cases even stipulated that the valves from time to time must be made
to blow-off by lifting the seal off the seat, in order to assure the correct functioning of
the safety valve. They can be made to open by hand at the latest when the working
pressure is > 85% of the response pressure.
Lifting is carried out by turning the twist-type lifting mechanism above the bonnet
in a counterclockwise direction. Turn the twist-type lifting mechanism back to the
stop again afterwards.
Safety valves without lifting device (version sGO; tGO)
In case of safety valves without lifting device -for technical reasons- the function
needs to be tested by the plant manufacturer.
Safety valves are the ultimate safety device for the tank or system. They must be
able to prevent impermissible overpressure even when all other upstream control and
monitoring equipment fail. To ensure these functional characteristics safety valves
require regular and recurring maintenance. The maintenance intervals are determined
by the operator independence of the operating conditions.
CAUTION:
For applications with the media hydrogen and helium, a more frequent maintenance interval
must be planned. If hydrogen embrittlement occurs on components or pipes in hydrogen
applications, the safety valves must always be replaced. Where sizes DN 6 and DN 8 are
used, a more frequent maintenance interval must be planned and a gas and gas mixture qua-
lity in accordance with ISO8573-1:2010[4:1:1] must be maintained because the narrowest
permissible flow diameter is undershot.
Assembly and maintenance instructions - 492, 492 GOX
www.goetze-valves.com
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