AAON LZ Series, Installation Operation & Maintenance

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Flow Measurement with the valve in the
throttled position
Step 1. The valve stem with its grooved rings
and positioning sleeve indicates the throttled
position of the valve.
The quarter turn graduations on the sleeve,
with the scribed line on the stem provide an
approximate flow measurement.
Note: The valve is shipped in closed
position. The indicator on the plastic sleeve
is aligned with the vertical scribed line on
the stem.
Step 2. Record the size of the valve and stem
position using the flow indicator scale.
Calculate the percentage of valve opening
based on the number of rings at the fully open
position.
Valve Size 2-1/2 3 4 5 6 8 10 12
Number of
Rings
5 5 6 9 10 12 18 28
(valve
fully open)
Step 3. Measure and record the differential
pressure across the valve in the throttled
position.
Step 4. Locate percentage of valve opening
on the bottom scale of Inherent Flow
Characteristic Curve with Valve in Throttled
Position. Project line vertically up to intersect
with the Valve Characteristic Curve and from
this point project line horizontally across to
the left of the chart and record the percentage
of maximum flow rate.