The design techniques discussed in this section are a summary of recommended “Do’s” based on features that have displayed significant impact on the durability and reliability of your product and equipment in service.
“Dos”
Design on the assumption that moisture and other corrosive mechanism will be present.
Seal all dissimilar metal (galvanic) couples.
Use conformal coating on printed wiring boards.
Use as easily replaceable anodic (consumable) part in assembling grounding or bonding connections.
Use only electrical connector boots that can be sealed with adhesives.
Carefully select a protective system for use on magnesium.
Complete the working of aluminum, steel, etc (drilling, cutting, grinding) prior to surface treatment.
Use surface treatments (anodize and conversion coatings) on aluminum.
Carefully select the metal plating use to provide sacrificial protection, barrier protection, as a third metal between two otherwise incompatible metals, or as a substitute surface.
Use a nickel strike under gold plating.
Use solder flux with lowest possible acid content.
Use metallic materials with the most corrosion resistant configuration (passivated) with minimum possible residual stressing.
Use fluorocarbon or fluorosilicone type materials for gaskets, “O” rings an seals.
Use low point drains.
Mount equipment an components at least 1/2 inch above potential standing water level.
Use hermetic sealing where possible.
Design for maintainability.
Use shoe box lids on enclosures.
Mount PWBs vertically with the edge connectors on vertical edge or back of board.
Mount electrical connectors horizontally.
Use drip loops on electrical cables and piping.
Use desiccant systems with visual indicators.
Use cooling systems that remove moisture and particulate matter.
Use “O” rings to seal around control shafts that must penetrate into an corrosive environment.
Be aware of various interior and exterior fluids which your product will be exposed to.
