View Single Post
Old 11-27-2013, 12:35 AM   #58 (permalink)
vlad
EcoModding Lurker
 
Join Date: Sep 2010
Location: Canada
Posts: 53
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by rmay635703 View Post
Key here is we likely DON"T need to DIY an inexpensive 500psi flammable gas pump, they exist but I have never come in direct contact with them to write down models and brands.

Ah well.
Almost any AC compressor can pump flammable gas. I filled up my home heat pump with dry propane instead of R22 refrigerant. You can pump to 350-400 Psi using just a R22 AC compressor. R410a compressors can pump 500 Psi.

The problem is I have 2 large and heavy type 1 cng tanks. They are huge but only 3 ft3 together. Lets see how much CNG they will hold at 500 Psi:

500/14.7=34 compression
34x3=102 volume uncompressed
102/127=0.8 GGE...... not much......

I need 1200-1300 Psi to get 2GGE

This is why I am thinking about "second stage compression".

What about using hydraulic cylinder to compress gas? First stage can easily compress to 200 Psi and we only need 6 times ratio to get 1200 Psi.

Benefits of using hydraulic cylinders: not expensive, low temperature, low speed, easy to rebuild ($20-$30 seal kit)
  Reply With Quote