This pressure feed is designed to allow the system to be operated at much lower pressures and still maintain a positive abrasive flow. According to CDS, a key feature of the system is the use or a variable pressure control valve. By custom-selecting a blast pressure, the operator is able to remove one or more coats of paint and leave other layers intact. An operator can blast clean thin, deformable surfaces with little or no substrate damage or distortion. In this system, the sodium bicarbonate blast cleaning abrasive is used in a manner similar to conventional open-nozzle blast cleaning, but the system employs water to control dust.
Water is injected at the nozzle, or by using a water collar.
Water pressure can vary from 10 to 500 psi, but has an optimum flow range of 0.5 gpm at 300 psi. In a manner similar to that described above, the water transmits the abrasive to the surface to be cleaned. Other manufacturers' abrasives and equipment offer some significant variations on the above approaches. The abrasive is aspirated into a high-pressure water blast cleaning unit through a specially designated venturi which prevents abrasive backflow. While Butterworth declined to identify the material, it is reportedly not a sodium bicarbonate-based product.