High-pressure Cleaning Research Articles

Precision Cleaning in a Production Environment with High-Pressure Water

The increasing contamination control requirements for disk drives, and the prevailing mandate to climinate chlorinated solvents in cleaning applications have allowed high-pressure water spray to emerge as an effective and environmentally sound method for cleaning. Certain substrates, such as machined metals and alloys, can be cleaned using high-pressure water to state-of-the-art cleanliness levels. Following developmental investigations in the laboratory, two cleaners utilizing high-pressure (up to 3000 psig), high-flow (up to 50 gpm) water have been procured for use at suppliers of critical disk-drive components. Acceptance-runoff, certification, and production-run cleanliness data pertaining two the two high-pressure cleaners are presented here in terms of liquid-born particle counts on contaminants extracted from substrates ultrasonically, or by means of a low-pressure water spray. Results indicate that residual particulate contamination levels on high-pressure sprayed parts may be lower by more than two orders of magnitude compared with those obtained by more conventional cleaning methods. The cleaning efficiency increases significantly with particle size. The importance of nozzle manifold design and placement, for both cleaning and drying, is demonstrated quantitatively with examples of the deleterious consequences of not optimizing them. The underlying cleaning mechanism is explained briefly. Potential advantages and disadvantages associated with high-pressure water spray cleaning are fully discussed, and recommendations are offered for utilizing this technology most effectively.

A Portable High-Pressure Cleaner for Tanks and Raceways

A Portable High-Pressure Cleaner for Tanks and Raceways

Experience with Advanced Instrumentation on Large Bore Engines

The author has been engaged in design, installation, commissioning, and subsequent operation of a ship automation system with advanced instrumentation. The paper deals with the instrumentation as such, without entering into details of the end use of this instrumentation.The instrumentation was installed in a motor tanker, and much thought was given to the planning of locating and securing components, selecting cable runs, screening and grounding methods. Experience shows that preparing and working according to such plans pay off in reduced electrical noise problems. Selection of sensors and other components has been found to be a tricky business. The severity of the ship environment can be misjudged. While temperature and vibration problems are at least expected, if not fully understood, the hazards of climbing crew members and liberal use of high pressure cleaning may be surprises .The instrumentation is considered overall successful, However, the paper points out some mistakes that were made. Good practice and well considered component selection help to reduce mistakes, but there are cases where components will not stand up to all requirements of the specification at the same time. These cases can hardly be avoided except through experience.