GE EVT-Pro, Technical Manual

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GE Title or job number
9/18/2012
In Situ PRV Testing, Technical Description
Overview
In Situ PRV testing enables the technician to accurately
determine the PRV’s set pressure without removing the PRV
from the installation. The test result obtained during in situ
testing is considered the ‘hot set pressure’, not the ‘cold set
pressure’, given that normal operating conditions are present
during testing.
During in situ testing, hydraulic force is applied to the PRV
spindle, fractionally lifting the disc off the seat. An installed
force transducer, records the hydraulic force necessary to lift
the disc from the seat. The EVT-Pro combines this
measurement with an indication of lift and an increase in
sound produced by flow through the PRV to determine the PRV
set pressure.
Graphic evaluation of the hydraulic force, lift, and sound
enables the technician to accurately determine the PRV set
pressure (Fig. 1).
Rev - 1.0 / Page 13 / 10/10/2012
Set Pressure (Green)
Hydraulic Force (Red)
Lift Indication (Blue)
Inlet Pressure (Brown)
Sound Indication
(Orange)