EA SV Series, Оригинальное руководство по эксплуатации

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5.6.2 Regular releasing of the safety valve
It is recommended to make the safety valve blow off from time to time through lifting, in depend-
ence for the respective system, in order to check the correct operation of the safety valve.
The lifting device is not to be operated when in a pressure-free state.
For safety vales with lifting device you have to increase the pressure in the pipes to 85% of the set
pressure.
Carry out the lifting either by means of a knurled nut above the spring bonnet or by actuating the
lifting lever on the upper part of the safety valve.
Safety valves without lifting device, like e.g. valves with head “C” (gas tight with cap) should be
brought to the release pressure only externally with gas or at a 100% clean device.
5.6.3 Leaks
Leaks may be caused in the case of safety valves due to pollution between the valve disc and seat.
By operating the lifting device small deposits of pollution can be effectively cleared from the valve
disc and seat. (In doing this, a clear stroke of the valve stem must be achieved).
If it fails to remove the pollution by operating the lifting device, it must be assumed that the sealing
surfaces are damaged. The damage can be removed be post-processing the sealing surfaces or
by changing the seat seal.
Repair work on safety valves in only to be carried out by the manufacturer or by officially approved
specialist workshops authorized by the manufacturer.
Leaks may also occur when the operating pressure is too close to the set pressure of the safety
valve.
The operating pressure of the device is to be at least 5% lower than the closing pressure of the
safety valve.
Leaks