Systems, components, and methods for low pressure delivery of plural component foam systems comprising solid particles from unpressurized supply sources

Various examples are provided related to polyurethane spray foam and its application. In one example, a method includes providing a system including a polyurethane spray foam ("SPF") raw material supply, a fluid handling system, an air source, a heated hose, a whip hose, and a metal stray gun. Each of part A and part B material streams, either or both of which include particles, are generated by the system and conveyed by the system through the system and into a disposable mixing nozzle engaged with the metal stray gun. A mixture of the part A and part B material streams can be applied, via the disposable mixing nozzle, to a surface or into a mold at a pressure of 250 psi or less. A polyurethane spray foam coating generated from the method can be applied at a thickness of from about 0.5 inches to about 12 inches.