Dynasonics 701_771C Series Insertion Ultrasonic Flow Meter - Manual (Page 20)

Rev. 12/97 -19- D77X
PROBE RETRACTION PROCEDURE
1. Retract the Probe by loosening the Upper Jam nuts
counterclockwise as viewed from the top of the probe
using the proper size wrench. If the pipe is under
pressure, the nuts must be turned alternately about two
turns at a time to prevent, binding as a result of
non-equal seal loading. In many cases, the line pressure
will cause the probe to retract. Should the probe bind, use
the retraction nuts on the lower side of the probe flange to
assist in the probe retraction. Continue this procedure
until the Probe is fully retracted into the Isolation Valve.
CAUTION: Do not run the drive nuts off the rods until the
isolation valve is fully closed.
2. After the
Probe is retracted past the "ball” in the isolation valve, the
Isolation Valve may be closed to isolate the Probe from
the line and the probe can be removed entirely.
3. CAUTION: If the sensor is not above the "ball" of the
isolation valve, the valve cannot be closed. If the valve
will not close smoothly, the body or tip of the probe is most
likely not above the "ball".
Attempting to force the valve
into the closed position may result in damage to the
sensor.
PART 2 - TRANSDUCER INSTALLATION
Retracting the Probe