Vapor-Flo 8990Freight not included. The Vapor Flo 8990 is ideal for both commercial and industrial use, delivering a pressure level of 2175 psi and a flow rate of 2. 7 GPM. The most powerful in the Vapor Flo line, this system is ideal for a range of applications, including stain removal, grease removal, and cleaning of concrete, flooring, machinery, and other surfaces. With a heavy duty 4. 0 HP motor, this machine is both efficient and powerful. The system's