Pressure should be used to deliver a high-velocity stream
of media in blast cabinets when the hardness of the
substrate material can handle the higher pressures and the
media used is low-cost. All other things being equal,
inexpensive media used on hard surfaces by a high value
operator favors the selection of a direct pressure blast
Cleaning operations can routinely be completed in a third or a quarter the time required when using suction cabinet. This is particularly true for cleaning thick layers of paint, scale, rust or corrosion.
Additionally, when a metallic media is required to prepare the required surface finish, a direct-pressure blast cabinet may be the optimal choice.
Some of the trade-offs for using pressure rather than suction cabinets may be, a higher purchase price as compared to an equivalent suction-blast cabinet, a more rapid wear rate of all the wear-components in the system, little opportunity to recover media after its first use, and higher CFM demands on the system air compressor.
Always wear appropriate personal protection equipment when operating machinery of any kind.