Tad Johnson <[EMAIL PROTECTED]> wrote: > (in response to Robert's comment) v > > Yikes! What kind of "cheap pump" are you talking about? Hydrogen > >should be handled with utmost respect and care. The pumps designed for > >natural gas will work, but I wouldn't use anything designed for > >air--including the tanks. Stick with the composite natural gas tanks > >for the sake of safety and PLEASE be careful! > > Scavenged pump from an old refrigerator. Been using it for over a year now > in this process. The tank > has an O2 sensor built into it now and I put a vacuum on it before I start > filling with H2. Then > I also bleed off a little H2 in the process under vacuum to make absolutely > certain the O2 > has been purged. 600-700 PSI is all I get out of the pump at it's maximum > output so it's > nowhere near the 3000 PSI rating of the diving tank. > > Tad > Mr. Johnson, while I am not a fan of the hydrogen economy, I admire your interest in the potential and practical application (hey, I could be wrong).
However, I ask that you carefully consider the risks you are taking employing the wrong storage container for the task. Please read: http://www.corrosion-doctors.org/Forms/embrittlement.htm In particular, please note this statement: "The most vulnerable are high-strength steels, titanium alloys and aluminum alloys", referring to susceptibility to hydrogen embrittlement. Virtually all diving tanks are made from high-strength steels and aluminum alloys. Also, this statement: "To address the problem of hydrogen embrittlement, emphasis is placed on controlling the amount of residual hydrogen in steel, controlling the amount of hydrogen pickup in processing, developing alloys with improved resistance to hydrogen embrittlement, developing low or no embrittlement plating or coating processes, and restricting the amount of in-situ (in position) hydrogen introduced during the service life of a part." Diving tanks do not have a plating or coating inside them. Your use of diving tanks for hydrogen storage negates all the above-mentioned methods of reducing risk. Finally, please remember these tanks were built to store oxygen (and in some cases some nitrogen), which are larger molecues than hydrogen. Unlike some hydrogen proponents, I do not even recommend the practise of using components designed for compressed natural gas with hydrogen. Again, CNG is not noted for embrittlement, and the molecules in natural gas (primarily methane), are much larger than hydrogen, making for potential leakage issues. I am aware that hydrogen tends to disperse quickly and float away. That doesn't mean we should count on this property as a reason to dispense with other safety measures. I understand that components rated for use with hydrogen tend to be somewhat expensive, but most safety precautions incur some cost. Wishing you all the best in your endeavours, Darryl McMahon ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark Printer at MyInks.com. Free s/h on orders $50 or more to the US & Canada. http://www.c1tracking.com/l.asp?cid=5511 http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://infoarchive.net/sgroup/biofuel/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
