Abstract: A recirculation block includes a top face and a bottom face that are connected by a right side face, a left side face, a front face, and a rear face. The recirculation block further includes a pair of junction block entry ports and a pair of side block entry ports. Both of the junction block entry ports are positioned on the bottom face. The first side block entry port is positioned on the right side face and the second side block entry port is positioned on the left side face. The recirculation block further includes a pair of exit ports. The first exit port is in fluid communication with both the first junction block entry port and the first side block entry port. The second exit port is in fluid communication with both the second junction block entry port and the second side block entry port.

Abstract: A recirculation block includes a top face and a bottom face that are connected by a right side face, a left side face, a front face, and a rear face. The recirculation block further includes a pair of junction block entry ports and a pair of side block entry ports. Both of the junction block entry ports are positioned on the bottom face. The first side block entry port is positioned on the right side face and the second side block entry port is positioned on the left side face. The recirculation block further includes a pair of exit ports. The first exit port is in fluid communication with both the first junction block entry port and the first side block entry port. The second exit port is in fluid communication with both the second junction block entry port and the second side block entry port.

Abstract: A dispensing system for settable liquids, such as urethane foams and coatings, catalyzed polyesters and epoxies, and other liquid compositions that cure or react and thicken or solidify, applies a flow of compressed air to purge the settable liquids from a mixing and dispensing apparatus, and a purge air control delays the application of compressed purge air to the dispenser for settable liquids to avoid disturbance of the dispensed settable liquid.

Abstract: A railroad car loader/unloader apparatus includes a mobile machine adapted to operate atop an open top rail car. The apparatus includes a plurality of support subassemblies with surfaces adapted to engage upper surfaces of sidewalls of the rail car when the apparatus is positioned thereon. The support subassemblies are removable. The apparatus also includes a boom structure with a bucket attached at an end thereof. The apparatus can move atop the rail car on its own power, or by coordinated use of the boom structure to push or pull the apparatus along the rail car. In an alternative embodiment, rollers are attached to the support subassemblies in a position to engage the sidewall's upper surface to reduce travel friction.