I've used two types of fuel pumps for Betsy.
Street Racing Fuel Pumps
I used a Holly Fuel Pump that was listed as being compatible with methonol. The problems that I had with it is that it doesn't pump very fast given all the restrictions in the fuel lines. It takes 60 seconds to fill the launch tube with 1/2 gallon of alcohol. Also the pump is non self priming and it doesn't deal well at all with crap in the fuel. I had to tear the pump down at BM2001 because a bit of plumbers tape got in the pump.
Max Pressure: 14psig Flow Rate: 140 gph max
Magnetic Drive Chemical Pumps
Little Giant Magnettic drive pump Larger Little Giant Magnetic drive pump
In 2002 I bought a magnetic drive chemical pump. This worked but suffered from many of the same problems that the holly fuel pump had with the exception of crap. Centrifical pumps don't care about dirt that much.
In 2003 I bought a much bigger pump but did not use it because I didn't bring Besty to BM that year. The idea was to improve the flow rate by using a bigger pump. Problems with this pump is that it draws much more power than the smaller pumps and will not run off my 1200W inverter.
Double Diaphram Pumps
A potential solution would be to use an air operated diaphram pump. These produce good flow rates on the order of 4-6 gpm max at decent pressure.
1) Self priming? 2) Can tolerate crap (1/32 diameter crap is no problem) 3) High Pressure, will pump up to 100 psig (same as air pressure used to operate the pump) 4) Good flow rate small pumps will pump 3-6 gpm. 5) Good for Chemical transfer. 6) Low air consumption, 1-6 scfm.
A yammaha DP-10
Explanation of points.
1) Self Priming is good. Often there is a need to setup and take down these systems. Pumps that require priming realy dislike air in the lines. Self priming pumps can pump air through if need be. (I had lots of problems with priming the holly fuel pump and the chemical pumps)
2) Tolerate crap. This is important cause the playa is a dirty enviornment. Another reason would be so that I can mix carbon poweder with the alcohol, this would produce floaty sparks after the main fire ball.
3) High Pressure. High Pressure is good because it means that pump can force the fuel to flow through small fuel lines, check valves and such. The previous pumps suffered because there flow rate dropped off quickly as the head pressure went up. Diaphram pumps should be able to keep a high rate of flow reguardless.
4) Good flow rate. The current restriction on Betsys firing rate the the length of time it takes to fill the launch tube. Curently it take 45 seconds to fill it. At a real 5 gpm it should take six seconds to fill the tube.
5) Pumps are made of polypropylene with PTFE diaphrams. This is compatible with methonol, alcohol and gasoline. And compatible with almost all colorants that I would want to use.
6) Low air consumption. Units require 1-6 scfm or air. This is low enough that I may be able to use the nitrogen tank operate the pump. Power for the centrifical pumps has been a real problem. The large pump I bough last summer won't run off the inverter I have.
Possible Problems: I have to check to see if the pressure regulator I have can deliver enough flow to run the pump.