DC

Douglas G. Calvin

KI Keystone International: 5 patents #5 of 50Top 10%
Chevron: 2 patents #1,772 of 4,788Top 40%
TI Tapco International: 1 patents #45 of 67Top 70%
TK Tyco Flow Control Kabushiki Kaisha: 1 patents #4 of 21Top 20%
📍 Houston, TX: #2,572 of 21,073 inventorsTop 15%
🗺 Texas: #16,798 of 125,132 inventorsTop 15%
Overall (All Time): #589,931 of 4,157,543Top 15%
9
Patents All Time

Issued Patents All Time

Showing 1–9 of 9 patents

Patent #TitleCo-InventorsDate
5934645 Rotary valve with pressure energized seal 1999-08-10
5765815 Rotary valve with pressurized energized seal 1998-06-16
5244183 Fugitive emission sealing assembly Edward G. Holtgraver 1993-09-14
4899775 Corrosion-resistant overlay for the edge of butterfly valves 1990-02-13
4846441 Methods and apparatus for adjusting a valve closure member William B. Scobie 1989-07-11
4773625 Corrosion-resistant overlay for the edge of butterfly valves 1988-09-27
4317384 Manual override drive apparatus Richard C. Babb 1982-03-02
4269211 Steam manifold distribution system for providing equal quality of steam in two lines Curtis E. Howard 1981-05-26
4205725 Method for forming an automatic burner for in situ combustion for enhanced thermal recovery of hydrocarbons from a well Curtis E. Howard, Robert W. Pitts, Jr. 1980-06-03