Hans Georg Schrey 
Review of the vacuum decay test in air-cooled steam condensers [PDF ebook] 

Polemic Paper from the year 2018 in the subject Engineering – System Science, , language: English, abstract: Condensing the capacity of air-cooled condensers is critical for proper functionality of steam cycles in power plants. Condensers operate in the low vacuum regime to promote the efficiency of power generation. Leakages enable ingress of ambient air into the steam cycle and thus impede condensation and power generation capacity. Therefore, vacuum tightness is essential for effective plant operation and must be verified by means of an acceptance test.
The latest revision of the VGB acceptance test code for the air-cooled condenser (VGB-S-131) proposes a simple procedure to verify ample vacuum tightness and evacuation capacity. However, the following report will demonstrate that the informational value of test results in connection with the proposed procedure are to some extent questionable. They cannot stand for themselves but need to be accompanied by further information gathered from other tests, as for example thermal performance tests. This puts the usefulness of the test itself into question.