All the advice from the other respondents is quite sound. EOSS takes
one more, perhaps paranoid, step, and that's to lightly dampen the
envelope and fill tube with a lawn spritzer before starting the fill,
and again until the envelope lifts its own weight. This suppresses the
most insidious source of ignition - an electrostatic discharge.
Once the envelope has plumped out, we kick up the fill rate to max,
sans regulator, using the tank valve to regulate the flow. If there's
any breeze, a slow fill creates the greatest hazard that a latex bag
is exposed to until burst, since that increases the chances of the
envelope hitting the deck or sharp jewelry on the handlers.
We abandoned regulators after experiencing entirely too many freeze-ups.
Our fill hose is 1/2" ID and 20 ft long reinforced rubber air hose - so
plenty of carbon black in the walls to dissipate any generated
73 de Mike W5VSI
On 10/25/13 8:42 AM, Hanson, Douglas R CIV SPAWARSYSCEN-PACIFIC, 63800
> All, I would like some help determining the safest use of hydrogen.
Hydrogen providers often caution me about static charge buildup if the
flow rate into the balloon is too fast. What is considered a safe fill
rate? How long should I take in filling a 1600g Hwoyee (assuming I'm
only using about 210cu.ft. of gas)? There are many CGA 350 regulators
available, but does the outlet pressure of the regulator matter? Single
stage or two stage? I look forward to the great feedback. Thank you.
> Ryan, KJ6YXG
> San Diego Near Space Project