TM 1-1500-204-23-7
(1)
Perform quality inspection of penetrant liquids.
(2)
Inspection process liquids and techniques selected should be rechecked to ensure that process is
appropriate for results desired and anticipated.
(3)
Production line equipment shall be properly set up and sequenced.
(4)
An inspector shall prepare himself and the area.
b.
Operative Precautions. Precautions to be taken during penetrant inspections are as follows:
(1)
Avoid contamination of inspection liquids
(2)
Maintain the wet developer bath at the concentration recommended by the supplying manufacturer.
(3)
Observe temperature limitations described in paragraph 3-5c
(4)
Perform a waterbreak test on a piece of polished steel to ensure the developer has sufficient wetting agent
c.
Temperature Limitations. The temperature of the penetrant, wet developer, dryer, and. part should be observed
to ensure the temperature does not exceed the limitations. Limitations for each are explained in the following
paragraphs.
(1)
Penetrant temperature. Most penetrants operate satisfactorily at temperatures as low as 40 °F (4 to 5°C),
but operation much below this temperature can result in unsatisfactory conditions. Most penetrants designed for use in
open tanks are reasonably stable at temperatures up to about 1 000F (380C).
CAUTION
If a penetrant is heated to the point where some of its lighter constituents are driven off, the
sensitivity of inspection may be greatly reduced. Volatile fumes may create a fire or health
hazard. Heating the penetrant is therefore not recommended.
(2)
Wet developer temperature. Wet developer, being a water mixed solution, cannot operate below the
freezing temperature of water. Heating wet developer above 90 °F (320C) does not improve its function.
(3)
Dryer temperature. The desired temperature of the dryer oven is 150 to 1 80 °F (66 to 82°C). Parts should
be removed from the dryer as soon as they are dry. If overheated prior to the application of the penetrant, excessive
evaporation of the penetrant may occur. If the part is allowed to remain In the dryer oven too long after the penetrant
has been applied, the sensitivity may be reduced. Temperatures above 180 °F (82°C) or excessive drying times may
decrease the sensitivity of certain fluorescent penetrants.
(4)
Temperature of part Warming parts to approximately 100 °F (380C) will minimize the required penetrant
dwell time. The warm part reduces the viscosity of the penetrant, permitting the penetrant to more readily enter the
discontinuities.
d.
Safety Precautions. The following safety precautions shall be observed when performing penetrant Inspection.
WARNING
Prolonged or repeated inhalation of vapors or powders may result in irritation of mucous
membrane areas of the body.
(1)
Adequate ventilation shall be used when handling cleaner, emulsifiers, penetrants or developers.
(2)
The following precautions shall be used when handling cleaners, emulsifiers, penetrants, or developers:
WARNING
Continual exposure to penetrant inspection products may cause skin irritation.
(a) Avoid contact of penetrant inspection products by wearing neoprene gloves.
(b) Keep insides of neoprene gloves clean.
(c) Wash exposed areas of body with soap and water.
3-2