Kanawha Air Pressure System

Can the CR4 community help with this one?

I have been corresponding with a retired gentleman from Ohio whose hobby is vintage fire apparatus. He has a photo of a 1918 Boyd chemical and hose car (photo below) that has the notation "Chemical Equipment - Kanawha Air Pressure System." He contacted me to try to get more information about exactly what a "Kanawha Air Pressure System" is.

Some searching revealed the following information:The Kanawha Chemical Engine Manufacturing Company, based in Charleston WVa, manufactured (perhaps among other things) fire apparatus in the early 1900's. There's not much to be found about them anymore, although one of their old brochures/catalogs is available from John's Western Gallery

I also located a patent assigned to the company for "improvements in apparatus for extinguishing fires of that class in which compressed air or other agent is used to expel the extinguishing fluid from a suitable receptacle." The device in the patent looks like it's designed for a fixed installation rather than a vehicle, but the principle may be the same.

I'm wondering anyone out there in our engineering community has more information about the Kanawha Chemical Engine Manufacturing Company, or about the "Kanawha Air Pressure System?"