Bates

Hydraulics 101 Smller hole in the tip makes more pressure, larger hole makes less pressure if everything else is constant (pump displacment) Flow sensitive unloaders or pressure sensitive unloaders are both attached to apump, the pump will only move X amount of water (all thing being constant), reduce the size of the tip and the pressure increases, enlarge the tip and the pressure decreases, the flow amount obviously increases with the increase in size of the tip size. The 'flow charts' are based on the amount of water that will flow throigh a fixed orifice at a given pressure. They do not take in account pressure drop due to hose, temperature etc. Basicly they charts are a guide, they are pretty accurate, but still a guide. My experience is typical soap injecters (downstream) start flowing soap with a '20 tip size on a 3000 or 3500 psi unloader machine that flows around 5 gpm, which means the soap injecter starts sucking soap around 250 psi, and would also suck soap with a '40 tip but the pressure would be around 70 psi. As the tip size increases the pressure drops if the flow remains the same. Good Luck

Sure, I can send pics, tell me where. I need some pics for my iles / marketing anyway, that would be another thing to mark off the list. This is about the 11th generation wash rig I have built/used. I have had vans, box trucks, trailers (open and closed). For me this is it, everything I need. Always remember, in all designs, every decision is a compromise. There is no perfect machine.

The Rig... 97 Ford F-350 diesel dually, commercial cap with side lift up doors, rear lift up door, 225 gallon water tank, Elite (soon to be HydroTek) skid machine, hose reels mounted on cub side, 'attic' area in top of cap holds long wands, surface cleaner. Extra water and extra machine on trailer if needed. Dell Inspiron laptop mounted in console between seats, printer underneath. 'porta-file' fits in console. Lettering includes full color before/after shots on sides and rear... (I have sold jobs to the car behind me at traffic lights.) Very maneuverable, (short wheel base). good fuel milage 14-16 mpg, everything I need inside....