GE EVT-Pro 2.0, Operation And Technical Manual, Page: 26 / 60

SECTION 19
EVT PRO 2.0 ® OVERALL SYSTEM ACCURACY
SECTION 20
EVT PRO 2.0
®
- THEORY OF OPERATION
Figure 20.1
– Theory of Operation / Force Analysis
The overall accuracy of in situ testing is based upon the accuracy of the test equipment
used, the accuracy of the gauged inlet pressure, and the accuracy of the effective seat area.
Of the three, effective seat area is the most critical element in determining an accurate set
pressure.
Typically the accuracy of the EVT PRO 2.0
®
is within 1% of expected set
pressure.
The ability to accurately determine PRV set pressure during in situ testing relies on three
known factors: (Refer to figure 20.1)
• Hydraulic force generated by test equipment
• Inlet pressure resulting from process pressure
• Effective seat area of PRV
EVT PRO 2.0
®
Operations and Technical Manual (Rev 1.0
– 2016)
NOT FOR COPY OR DISTRIBUTION Page 22