From: peter@tsto.co.uk   
      
   On 19/07/15 17:33, dlzc wrote:   
   > Dear Peter Fairbrother:   
   >   
   > On Sunday, July 19, 2015 at 8:38:44 AM UTC-7, Peter Fairbrother wrote:   
   > ...   
   >>>> "something" bromate might get closer, due to   
   >>>> the massive bromate ion.  And it is used in   
   >>>> solid rockets sometimes.   
   >>>   
   >>> A bit expensive though, and CaCl2 is cheap, is   
   >>> reasonably non-toxic, is sufficiently non corrosive   
   >>> enough,   
   >>   
   >> actually, on reflection corrosion may be a problem.   
   >> I am not sure what the pumps will be made of though,   
   >> and the test pumps do not have to be made of the same   
   >> stuff as the real pumps.   
   >   
   > H2O2 is sensitive to free iron, and of course visible light.  Polyethylene   
   should be a major constituent, unless you expect long periods at elevated   
   temperatures.  What sort of boost pressures?  If you only need 1 or 2 bar, you   
   can do a single stage    
   mag drive...   
      
      
   About 6-12 MPa (870-1740 psi).   
      
   Well the seals are teflon, but I don't know about the case and impeller   
   - usually I'd think titanium, but Ti and peroxide don't go that well   
   together, so maybe they will use aluminium. I will ask.   
      
   A little decomposition in the pump is however acceptable, but anything   
   faster than very slow corrosion of the pump probably isn't.   
      
   Or maybe the oxide coating on Al will wear off in the somewhat extreme   
   conditions inside the pump - I don't know.   
      
   (I am advising, not building the pump myself - I have built LOX oxidiser   
   pumps before, but not a peroxide pump)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)