AMPP CP3 Technologist flashcards

35 cards. Read the term and the definition here. The deck at the top of this page is optional.

Electrochemical corrosion cell

A corrosion cell requires an anode, cathode, electrolyte, and metallic path. Removing any one element stops current flow, which is the basis of all corrosion control.

Galvanic series

A ranking of metals by corrosion potential in a specific electrolyte such as seawater. Metals further apart in the series create a stronger galvanic couple when joined.

Small anode large cathode

A geometry where a small anodic area is coupled to a large cathodic area. Current density at the anode is high, producing rapid localized penetration.

Critical pigment volume concentration

The pigment loading at which binder is just sufficient to fill voids between particles. Above this value, coating porosity rises and barrier protection collapses.

Osmotic blistering

Blistering driven by soluble salts or hydrophilic material at the interface drawing water through the film by osmosis. Prevention is removal of surface contamination before coating.

SSPC-SP 10 near-white blast

Abrasive blast cleaning that leaves only light staining on no more than 5 percent of each unit area of surface. Equivalent to NACE No. 2.

SSPC-SP 6 commercial blast

Abrasive blast cleaning permitting staining on no more than 33 percent of each unit area of surface. Equivalent to NACE No. 3.

ISO 8501-1 Sa 2 1/2

Very thorough blast cleaning in which the surface is free of visible oil, grease, dirt, mill scale, and rust, with only slight staining permitted.

Surface profile measurement

Per ASTM D4417, profile is measured with replica tape and a depth micrometer or with a stylus instrument. Typical epoxy specifications call for 50 to 75 micrometres.

Dew point margin

Substrate temperature must be at least 3 degrees Celsius above the dew point before blasting or coating, as defined in ISO 8502-4.

Waterjetting WJ-2

A very thorough waterjet cleaning grade in NACE No. 5 / SSPC-SP 12, removing most contaminants while permitting some staining, without a profile requirement.

Zinc-rich primer mechanism

Zinc dust at roughly 80 percent or more by weight in the dry film provides sacrificial galvanic protection to steel at breaks and defects in the coating system.

Amine blush

A carbamate surface deposit formed when amine-cured epoxy cures at low temperature or high humidity. It must be removed before recoating or adhesion fails.

Aliphatic polyurethane topcoat

A UV-stable topcoat that resists chalking and gloss loss. Aromatic polyurethanes are cheaper but yellow in sunlight and suit interior service.

Cathodic disbondment resistance

A coating property describing resistance to disbonding when steel is cathodically protected. Critical for buried and submerged pipe and tank coatings.

Coal tar epoxy restrictions

Coal tar epoxy is limited by worker exposure and waste regulations. Modified and phenolic epoxies commonly substitute in immersion and lining service.

Dry film thickness formula

Dry film thickness equals wet film thickness multiplied by the percent volume solids of the mixed product, divided by 100.

Airless spray tip wear

A worn tip has an enlarged orifice, lowering pressure and degrading atomization. Tips are replaced when flow rises or the fan pattern deteriorates.

Stripe coating

Applying extra coating to edges, welds, cutouts, and fasteners before the full coat, because sharp geometry produces thin films during normal spray application.

Pot life

The usable working time after mixing a multi-component coating. Exceeding it raises viscosity and prevents proper flow and cure.

Plural-component proportioning

Equipment that meters and mixes base and curing agent at a fixed ratio. Ratio verification and solvent flushing are required at start-up and shutdown.

SSPC-PA 2 spot definition

A spot is the average of three gauge readings. A test area of about 100 square feet contains five spots for thickness verification.

SSPC-PA 2 80-120 rule

For films up to 30 mils, each spot must be at least 80 percent of the specified minimum and no more than 120 percent of the maximum.

Holiday testing

Detection of discontinuities using low-voltage wet sponge for thin films or high-voltage DC for thick films. Excess voltage can damage sound coating.

ASTM D3359 tape adhesion

A cross-cut tape test for films under about 5 mils, reported in classes from 5B (no loss) to 0B (major loss).

ASTM D4541 pull-off test

A quantitative adhesion test using a bonded dolly pulled from the coating. Results are reported in MPa or psi along with the failure mode.

Inspection and test plan

A document listing inspection activities, hold points, witness points, and acceptance criteria. Work cannot pass a hold point without documented sign-off.

Order of precedence

The contractual hierarchy for resolving document conflicts, typically contract, drawings, specification, then referenced standards. Conflicts are resolved in writing before work.

Nonconformance report

A document recording a deviation, its disposition, and the corrective action required. Rework is tracked to closure before final project acceptance.

Type CE blasting respirator

A supplied-air respirator required for abrasive blasting, providing respiratory and head protection. Hearing protection is also required at blasting nozzles.

Confined space oxygen range

Atmospheric testing for entry accepts oxygen between 19.5 and 23.5 percent, alongside testing for flammables and toxics and a written permit.

VOC compliance by thinning

Adding thinner to a compliant high-solids coating can raise volatile content above the regulated limit, making the applied product noncompliant.

Failure investigation sequence

Document conditions and history, sample failed and sound areas, perform laboratory analysis, determine root cause, then specify repair matched to the original specification.

Wrinkling on recoat

A defect caused by recoating too soon or using an incompatible thinner, trapping solvent in the lower film. The surface swells and shrinks unevenly.

Pinpoint rusting

Small rust spots across a coated surface, indicating thin film, insufficient cleaning, or inadequate salt removal rather than a general coating breakdown.