Washing (3)

Question 1

Factors that impact removal of excess penetrant:

Answer 1

• surface condition
• part geometry
• shape and size of discontinuities

Question 2

Water Washable (A)

Answer 2

• fluorescent (1), visible (2), dual (3)

- chemicals in penetrant differ from others, soap or emulsifier is added when penetrant is made to assist in washing

Question 3

Best method of removing water washable penetrants:

Answer 3

• coarse water spray
• no closer than 12in to part at 45° angle
• water temp = 10°-38°C
• rinsing should not exceed 120 seconds
• rinse under black light

Question 4

Advantages of Water washable (A)

Answer 4

• easy wash with water
• fast single step
• good for volume testing of small parts
• good on rough surfaces
• good on complex geometries

Question 5

Disadvantages of Water washable (A)

Answer 5

• easy to over-wash
• not reliable for detecting shallow surface discontinuities
• not reliable on reruns
• susceptible to water contamination
• requires water availability

Question 6

Lipophilic Post Emulsifier (B)

Answer 6

• 100% oil based
• immersed in lipophilic bath
• mixes with penetrant
• fast acting (30sec)
• used on high production parts with smooth surface and simple geometry

Question 7

Hydrophilic Post Emulsified (D)

Answer 7

• 20%, hydrophilic emulsifier, 80% water
• weaker than lipophilic
• pre-rinsed with water prior to hydrophilic immersion
• needs a mechanical action
• wider variety of parts than lipophilic

Question 8

Post Emulsified (B&D) Advantages

Answer 8

• highest sensitivity
• not easily over washed
• excess penetrant can be washed with water after emulsification
• Hydro water contamination isn’t to critical
• parts can be re-run several times

Question 9

Post Emulsified (B&D) Disadvantages

Answer 9

• two steps
• emulsification and emulsification times are critical
• difficult to remove excess penetrant from rough surfaces
• re-runs can’t be done readily with lipophilic
• lipophilic more susceptible to water contamination

Question 10

Solvent Removable (C)

Answer 10

• solvent dampened cloth
• cloth or tissue is lint free
• fluorescent (1), visible (2), dual (3)

Question 11

Solvent Removable (C) Advantages

Answer 11

• portability (type 2)
• no water needed
• good for spot checks
• re-run ability

Question 12

Solvent Removable (C) Disadvantages

Answer 12

• time consuming
• solvent flammability
• not used in open tanks
• difficult on rough surfaces
• difficult on complex geometries