WA_SV/EV
04 / 2014
Maintenance:
NI-Safety- / Relief Valves are designed regarding design and construction in such a way that an optimum of quality is achieved, and that they are
easy to service. A minimum of care and maintenance is the result when our fittings are applied.
For the replacement of spare-parts it is also recommended to have this work executed only in an authorized workshop. If no suitable repair
means are available it is best to return the complete safety valve to the plant of Niezgodka GmbH. All spare-parts supplied by us are suitable for
the installation into our safety- / relief valves without restriction. It is, however, necessary to state in the order the number of the delivery
note/invoices or the commission number since the safety- / relief valves supplied are adjusted to their particular application.
Test intervals:
The minimum test intervals for safety- / relief valves especially activated by steam are four weeks. Test intervals for other applications must be
determined by the user in compliance with the operation conditions. Tests and examinations are to be executed at least during each internal or
external examination of the pertaining pressure device.
Regular releasing:
The release device of safety- / relief valves must be actuated regularly in order to examine the function and to remove soiling, if any.
This is possible manually in the case of valves with valve head “A”, “B”, “E”, “M” and “H” at a pressure rate ≥ 85% of the set pressure.
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.
Leaks:
Leaks may be caused in the case of safety- / relief valves due to soiling between seat (001 / 003) and disc (060) or through damage of the
sealing surfaces that were caused on account of soiling in the medium or by the medium itself. Soiling can be removed by causing the safety- /
relief valves through releasing to blow off. If it fails to remove the soiling in this way, it must be assumed that the sealing surfaces are damaged.
The damage can be removed by post-processing (lapping). The work involved should be carried out only in the plant of the manufacturer or by a
workshop authorized by the manufacturer. Leaks may also occur when the operating pressure is too close to the reaction pressure. In such a
case, the design of the safety- / relief valves is to be examined.
Corrosion protection:
NI-Safety- / Relief Valves that are not corrosion protected are provided with a protective paint cover in the plant of the manufacturer. In a moist
environment it may become necessary to apply later additional corrosion protection layers. In this case it must be seen to it that the function of
movable components (e.g. spindle (080) and disc (060)) is not affected. Heads with manual release, the blowing off space and freely blowing off
safety- / relief valves should not be painted later. For heavily corrosive conditions, safety- / relief valves made of special steel should be used.
For fürther information, see our website
Attention!
Care must be taken to ensure that the system is depressurised prior to assembly, dismantling or opening of the safety/relief valve.
The remaining dimensions and seal properties, preloading forces, tightening torques etc. are to be determined by the user
themselves in accordance with the operating instructions. In doing so special attention must be paid to the following:
Medium residues in the safety/relief valve or in the spring cap represent a serious chemical burning, burns and poisoning hazard.
It must, therefore, be established prior to removing a valve from the plant which medium could be present in the safety/relief valve.
Appropriate safety measures must be taken.
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