Inventor
HOLTGRAVER EDWARD G
US16 patents
⚠️ This page may combine multiple inventors who share the name “HOLTGRAVER EDWARD G”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
QTRCO INC
6 patentsUS10533583B2Jan 14, 2020
System for determining safety margin of an installed driven member
QTRCO INC3 citations71
US10132337B2Nov 20, 2018
Actuator assembly for conducting partial stroke testing
QTRCO INC2 citations71
US12590594B2Mar 31, 2026
Pipeline actuation system
QTRCO INC0 citations60
US12460737B2Nov 4, 2025
Line break device
QTRCO INC0 citations60
US12146589B2Nov 19, 2024
Actuator assembly for conducting partial stroke testing
QTRCO INC0 citations50
US11879564B2Jan 23, 2024
Rotary valve lockout apparatus
QTRCO INC0 citations50
KEYSTONE INT
5 patentsUS5244183ASep 14, 1993
Fugitive emission sealing assembly
KEYSTONE INT55 citations92
US4711427ADec 8, 1987
Apparatus for connecting a valve element to a valve stem
KEYSTONE INT25 citations92
US4570901AFeb 18, 1986
Positioning assembly for use with rotatable valves
KEYSTONE INT32 citations92
US4399833AAug 23, 1983
Valve assembly
KEYSTONE INT35 citations92
US4410163AOct 18, 1983
Valve seat
KEYSTONE INT25 citations81