Granted Patent
Utility
US 6,725,706 · App. 10/097,908
Device and method for blowing down and measuring the back pressure of chemical reactor tubes
Inventors:
Clifford L. Johns, Daniel D. Sympson
Patented Case
View Patent ↗
Granted: Apr 27, 2004
Filed: Mar 14, 2002
Inventors
Clifford L. Johns
Daniel D. Sympson
Assignee (at issue)
Tubemaster, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.