FLUORESCENT PENETRANT INSPECTION

FLUORESCENT PENETRANT INSPECTION AT GE McAllen

Pre Wash

Excess surface penetrant is removed by means of a water wash.

Water temperature shall be between 50 – 100 degrees F.

Water pressure shall not exceed 40 psi.

If hydro air nozzle is used, air pressure shall not exceed 25 psi.

Since post emulsified penetrants are oil based, only 90-95% of excess surface penetrant will be removed.

TYPE I: FLUORESCENT PENETRANT METHOD “D”

HYDROPHILIC POSTEMULSIFIABLE

Hydrophilic Remover

Water based detergent used to make penetrant water soluble.

Hydrophilic concentration, for dip applications, shall not exceed maximum listed in as per applicable technical data.

Concentration shall be maintained within +-3% of original concentration.

The Remover solution shall be mildly agitated during contact time.

To stop the emulsification time water is applied.

Preparation

Parts shall be free of contaminants that may block Penetrant from entering surface discontinuities.

Final Washing

Specifications require that water nozzles be kept a minimum of 12 inches from the part surface during washing, when possible.

Part configuration may dictate a need for closer proximity.

At all times, this final wash should be done under black light to ensure proper washing.

Any Questions?

Penetrant Application:

Penetrant may be applied by dipping, spraying, flowing or brushing.

It is important to ensure that all surfaces to be inspected have been covered in penetrant.

Drying

Clean shop air, up to 25psi, may be used to blow off excess water prior to placing the part in the dryer.

Parts should be positioned to prevent pooling of water during drying process.

The minimum amount of time required to dry the part shall be used.

Excessive exposure to, or excessive temperature may degrade the dyes in the penetrant.

Dry Developer

Parts shall be free of moisture before dry developer is applied.

The Developer – May be applied by spray (manual or electrostatic), dust cloud, storm chamber, etc.

Whichever means of application is chosen, it is important that the parts be covered completely and evenly with the dry developer powder.

Excess developer can be removed by gentle applying air (at 5 psi or less) or by shaking or tapping.

Development time begins immediately upon applications of the developer.

The minimum development time is 10 minutes, the maximum development time is 4 hours or as per the technical data.

Inspection

All indications shall be evaluated by wiping with a solvent dampened cotton swab

(A single wipe, not multiple wipes, is allowed),

then redeveloped. Development time after wiping shall be equal to the original dwell time.

Indications that reappear shall be considered relevant

and compared against the appropriate acceptance criteria.

The size of indications shall be made by direct measurement using the appropriated calibrated gauges.

PSM-5 Process Control Test Panel

ANY QUESTIONS?

TYPE I: FLUORESCENT PENETRANT METHOD “D”

HYDROPHILIC POSTEMULSIFIABLE

Process Control Test Panel – shall be processed using production parameters established for the sensitivity

class represented by that panel (including dwell times, pressures and temperatures), and the

results shall be equal to those obtained when the baseline was established. (per QCWI AA-009)

History

One of the most effective Nondestructive Testing Methods for the detection of discontinuities at the surface is liquid penetrants. Liquid Penetrants, as we know it today, has had an interesting beginning

since back in the late 19th century. Inspectors primarily involved in the inspection of railroad parts used a thin oil to penetrate discontinuities in objects like railroad axels, wheels and crank shafts.

TYPE II: VISIBLE PENETRANT METHOD “C”

SOLVENT REMOVABLE

ANY QUESTIONS

TYPE II: VISIBLE PENETRANT METHOD “C” SOLVENT REMOVABLE

PENETRANT INSPECTION

(PI)

Solvent

Types and methods of Liquid Penetrant Testing.

(Categories and designations contained in AMS-2644)

Developer

Class 1:

halogenated

Class 2:

nonhalogenated

Class 3:

special application

Sensitivity

Method

Form a:

dry powder

Form b:

water soluble

Form c:

water

suspendible

Form d:

nonaqueous

Type I

(for fluorescent)

Form e:

nonaqueous

Type II

(for visible)

Level ½*:

ultra low

Level 1:

low

Level 2:

medium

Level 3:

high

Level 4:

ultra high

Type

Method A:

water washable

Method B:

lipophilic

postemulsifiable

Method C:

solvent removable

Method D:

hydrophilic

postemulsifiable

Type I:

fluorescent

penetrant

Type II:

visible

penetrant

The American Society for Nondestructive Testing, Inc.

Summary

The penetrant process is highly dependent on the operator’s skill, knowledge, vigilance and integrity. Unlike the operator who produced the part, there is no tangible evidence (no permanent record) of the quality of the test. The reliability of and confidence in the testing is totally dependent on the operator. For reliable liquid penetrant testing, the personnel performing the processing and examination are required to be:

Technology today requires hardware to perform at ever increasing levels. Thermal and dynamic stresses

can quickly cause small discontinuities into flaws that may decay their performance or eventually bring about their failure.

Inspections not done, or not done in accordance with the prescribed requirements, may lead to costly failures, delays to customers, and other wide reaching consequences.

Physically and mentally qualified to perform the required processing steps,

Trained and experienced as required in performing the actual processing steps,

Alert to consistent processing and resultant indications,

Motivated to perform with vigilance at the required detection and reliability level, and

Capable of consistent, independent and unbiased decision based on interpretation

of resultant penetrant indications.

Introduction

Penetrant Inspection (PI) is a method of enhancing the visual detection of surface related defects in non-porous materials. Liquid penetrants can seep into various types of surface openings by Capillary Action*. Because of this, the process is well suited for the detection of all types of surface cracks, laps, porosity, shrinkage areas and similar discontinuities.

*Capillary Action- The tendency of liquids to penetrate or migrate into small openings, such as cracks, pits or fissures.