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GrainPro®
Cocoon™
Lite Instruction Manual
MA4061RAD1117-1
7.8. PRESSURE DECAY TEST (PDT)
7.8.1. After completely zipping and closing all the ports
of the Cocoon
TM
Lite, perform a Pressure
{Vacuum} Decay Test (PDT) to ensure gas-
tightness:
a. Use a digital manometer.
7.8.2. Either a commercially available or improvised U-
tube manometer can be used to monitor the
pressure.
7.8.3. Connect the manometer hose into the flexible
inlet (gas sampling port) of the Cocoon lite.
7.8.4. Use a vacuum pump [at least 2.3 cubic meters
per minute with 600 watts (0.80 horsepower)
centrifugal pump]:
a. Connect the vacuum pump hose to the inlet
port of the Cocoon
TM
lite.
b. Create at least -250 pascals (Pa) or -25
millimeters’ water (mm H2O) vacuum.
Doing this can also help engage the zipper tracks properly as there may be imperfections during
zipping.
▪
For it to be considered sufficiently airtight, the final pressure should not be greater than
one-half (1/2) of the initial pressure (created by the vacuum pump) within five (5)
minutes.
▪
If the PDT test failed, check for holes/tears and poorly sealed zipper then repeat the
PDT procedures.
7.9. TENSIONING OF STRAPS
7.9.1. Pull the protective flap down over the zipper track.
Tighten the straps to pull any slack on the sidewall
up away from the ground. Check that the protective
flap over the zipper track is not displaced.
