If the hot exhaust gas flow is suddenly interrupted by an abrupt burner shutdown (e.g. in the event of a power failure) or other circumstances, leads to an enormously high negative pressure being generated in the exhaust gas line. This can lead to deformation of the exhaust gas line or to irreparable destruction. This can be prevented especially in large plants by the use of an implosion relief value. The normally closed valve opens automatically in case of negative pressure and allows air to flow in to neutralise the vacuum in the exhaust gas line.
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