The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 20, 2012
Filed:
May. 22, 2009
Juha Saukko, Helsinki, FI;
Juha Saukko, Helsinki, FI;
ABB Oy, Helsinki, FI;
Abstract
Exemplary embodiments relate to a method for verifying a leak situation in a liquid transfer system a system and a control unit for implementing the method. The liquid is transferred with a frequency-converter-controlled pump from a lower pressure to a higher pressure and where liquid is prevented from being transferred from a higher pressure to a lower pressure with one or more check valves positioned in a pipe system. The method includes generating, for the frequency converter, motion information on the motion of the pump between the motion operations, and indicating a leak situation of the check valve if the direction of operation of the pump is, in the motion information, opposite to the direction of operation during the use of the pump.