74147990
Mar 15, 1991
Dec 10, 1996
[installation and repair of purifying and separating devices, apparatuses, and systems, especially for the separation of materials from liquid or gaseous media by centrifugal force, and of cyclones]
Building Construction and Repair[design for others in the field of purifying and separating devices, apparatuses, and systems, especially for the separation of material from liquid or gaseous media by centrifugal force, and of cyclones]
Computer and Scientific