AMPP S-CAT flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Wet film to dry film
- WFT = DFT ÷ volume solids fraction. A 65% solids coating needing 8 mils DFT requires about 12.3 mils wet film at application.
- Theoretical coverage formula
- Coverage in ft²/gal = 1604 × volume solids ÷ DFT (mils). This gives the maximum area one gallon can cover at that thickness.
- Transfer efficiency
- The fraction of sprayed coating that lands on the target. Airless typically 40–60%, conventional air spray 25–40%, HVLP often above 55%.
- Airless tip orifice effect
- Flow through an airless tip increases roughly with the square of orifice diameter, so doubling orifice size about quadruples flow at constant pressure.
- Pump ratio meaning
- Outlet fluid pressure equals pump ratio times inlet air pressure. A 30:1 pump at 60 psi air produces about 1800 psi fluid.
- HVLP definition
- High-volume low-pressure spraying uses atomizing air at the cap of 10 psi or less, reducing overspray and bounce-back.
- Pot life
- The working time after mixing multi-component coatings before viscosity rises beyond use. Expired material must be discarded, not thinned back into service.
- Stripe coat purpose
- A first pass applied by brush or spray at edges, welds, and corners to build thickness the broad spray pass cannot reach.
- Spray gun distance
- Typical spray distance is 6–12 inches from the surface, held perpendicular, with 50% overlap between passes for uniform film build.
- SSPC-SP 5
- White metal blast cleaning, NACE No. 1. Removes all visible oil, grease, dirt, mill scale, rust, and coating, leaving a uniform gray-white surface.
- SSPC-SP 10
- Near-white blast cleaning, NACE No. 2. Allows staining on no more than 5% of each unit area; removes nearly all visible residue.
- SSPC-SP 6
- Commercial blast cleaning, NACE No. 3. Removes at least two-thirds of visible residue, allowing staining and tight residues on the remainder.
- SSPC-SP 7
- Brush-off blast cleaning, NACE No. 4. Removes loose mill scale, rust, and coating while leaving tightly adherent material intact.
- ISO 8501 rust grades
- Rust grades A through D describe initial steel condition: A intact mill scale, B rusting mill scale, C mill scale gone with pitting, D general pitting.
- Anchor profile range
- The surface roughness produced by blasting, usually 1.5–3.5 mils for grit. It must fall within the coating manufacturer's specified range.
- Replica tape measurement
- A foam tape pressed against blasted steel captures profile depth, read with a micrometer. Coarse tape covers roughly 20–50 µm.
- Soluble salt limit
- Chloride contamination is often limited to about 3 µg/cm² for immersion service. Tested by the Bresle patch method per ISO 8502-6/9.
- Dew point rule
- Steel temperature must be at least 3°C (5°F) above the dew point during blasting and coating to prevent condensation on the surface.
- Relative humidity limit
- Most coating specifications require relative humidity below 85% during application and cure, unless the product data sheet states otherwise.
- Power tool cleaning
- SSPC-SP 3 removes loose material with power tools; SSPC-SP 11 removes to bare metal, leaving a roughened surface for coating.
- Mill scale removal
- Mill scale is a cathodic oxide layer that must be removed because it causes galvanic corrosion and coating disbondment if left under a film.
- Grade D breathing air
- Supplied air for respirators must contain 19.5–23.5% oxygen, carbon monoxide below 10 ppm, and no oil mist or objectionable particulate.
- Confined space testing
- Atmospheric testing for oxygen, flammability, and toxicity is required before entry and continuously during work inside tanks and vessels.
- SSPC-PA 2 acceptance
- Each DFT gauge reading must be at least 80% of the specified thickness, and the average of readings must equal or exceed the specification.
- DFT gauge types
- Type 1 magnetic gauges are least accurate; Type 2 constant-pressure gauges are more accurate. Multiple readings per area are averaged.
- Holiday detection
- Low-voltage wet sponge testing finds pinholes in thin films; high-voltage spark testers are used for thicker films with voltage set per thickness.
- Pull-off adhesion test
- A dolly is bonded to the coating and pulled until failure; results in psi or MPa are compared to the specified minimum adhesion value.
- Static ignition control
- Bonding and grounding of containers and equipment during solvent transfer prevents static discharge that could ignite flammable vapors.
- Cure verification
- Solvent rub or MEK test confirms a coating has cured enough for recoating or service, based on the product data sheet method.
- Inspection record content
- Each lot record should capture ambient temperature, relative humidity, dew point, surface profile, DFT readings, and cure verification results.
- Oxygen deficiency
- Atmospheres below 19.5% oxygen are immediately dangerous; entry requires supplied air and continuous monitoring, never a filter respirator.
- Solvent vapor flammability
- Coating solvents form flammable mixtures with air; lower explosive limit values dictate ventilation and gas monitoring requirements before and during work.