Another CAFS question

[PrestoC1]

Does anyone know what the rule is for how large a compressor you need for a system? We are being told that the system is limited by the foam injector, and I can figure that one out. But I can not find how much air you need for a desired finished product flow. If anyone has any info, it would be greatly appreciated!!!

[SBLGFD]

We tend to run about 2 parts foam solution ( water and concentrate ) to 1 part air. 2 Gpm to 1 CFM - this make a decent wet foam. If anything we error to less air more water, I think LA County is 3 GPM to 1 CFM or so. Again these are for wet foam. Dry foam is way high on Air and low on foam solution. Our compressor is 200 CFM.

SBLG

[PrestoC1]

Thanks SBLG. Neighboring VFD just got a new rig with a 500 gpm pto pump and a 60 cfm compressor. They say on the CAFS side they can run two 1.75" and the system is at max capacity. Mfg said that this compressor was the largest they could get on this truck due to the setup. We are looking at the same type of vehicle and pump.

What do you run for CAFS attack lines: 1", 1.5" or 1.75"?

[SBLGFD]

PrestoC1

we run all 1 3/4 hand lines. One preconnect is 2 1/2" with a wye and then dual 1 3/4. Not really needed with CAFS due to no Friction loss but if we are in a non CAFS opperation it helps.

SBLG