good practices user guide - penetrant testing

7/28/2019 Good Practices User Guide - Penetrant Testing

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PENETRANT TESTING

Good Practices User Guide

Coordinator Associated Beneficiaries


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TABLE OF CONTENTS

Topic Sheet P01 General points

Main processes of penetrant testing

Topic Sheet P02 Products used for manual inspection

Accessories and devices for quality control for manualinspection of penetrant testing

Topic Sheet P03 Constraints and environmental risks

Risks for the operator associated with the implementation ofpenetrant inspection

Topic Sheet P04 Approach to reduce the environmental footprint of the penetrant

testing

Practices to minimize risks of accidents

Improvements for a greener manual penetrant testing


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General points

Penetrant Testing

The penetranttesting can beperfom on any typeof material (nonporous)

This technique can

only allow thedetection ofthrough holesdefects.

Penetrant testing (PT) is a method of non-destructive testing developped at thebeginning of the 20st century, which allows surface defects detection. With themagnetic particles testing, this technique represent 50% of the non-destructivefield.

This technique consists in applying on the surface to be inspected, a penetrant

liquid which will seep into the surface defects. After impregnation, the penetrantexcess is removed from the surface. Once dry, the surface is then covered witha thin layer of developer which will act as a blotter and suck the penetrantpresent in the defects. It gives colored or fluorescent indication, characteristic ofthe defect.

This technique can detect through the surface defects on nonporous materialssuch as:

Cracks. Quenching cracks. Folds.

Penetrant testing method requires the use of chemicals at each step of theinspection.

Step-by-step penetrant testing implementation:

The time required for the realization of a penetrant inspection exceeds one hour.

Preliminary cleaning Penetrant application and impregnation

Removal of

penetrantexcess

Developperapplication

Inspection Last cleaning

TopicSheet

P01


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Main processes of penetrant testing

They are different methods of penetrant testing:

Pre-emusilfied penetranttesting method

Post-emulsified penetranttesting method

Penetrant application

Removal of penetrantexcess by using water

Adding an emulsifier on thesurface part

Chemical reaction between thepenetrant and the emulsifier during

a controlled time

Removal of water excess

Penetration time : 10 to 30 minutes

Penetrants usedcan be red or

fluorescent, pre or

post-emulsified

Some penetrantscan be removedwith solvent-

soaked rags

TopicSheet

P01

The emulgation operation remains a delicate step of theimplementation which may desorb the penetrant out of defects



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Factsheet Products used for manual inspection

Penetrant Testing

02

Types of products:

Cleaning products: The use of cleaning products is a preliminary operation to the

penetrant testing operation. The objective is to obtain a clean surfaceto allow the penetrant to seep into defects.

Main cleaner products used: ethyl acetate, acetone, isopropyl alcohol,...

There are other types of cleaning processes: chemical, mechanical(blasting, sandblasting). They are generally not allowed orimplemented with great caution (may occasionally recap defects).

Developpers : Developpers allow to view defects by capillary action. Developpers used: dry, wet organic or aqueous-based, peelable. Detection time: 10 to 30 minutes.

Penetrant products : Penetrants used : - Colored, fluorescent, mixed,

- Pre-emulsified, post-emulsified, - Thixotropic,

Penetration time: 10 to 30 minutes.

Product packaging:

Aerosol cans. Bulk.

Application methods of penetrating products:

Pulverization. Brush (well suited for localized examinations, for example for

checking welds or repairs).

Electrostatic spray (organic molecules are polarized at the exit of theelectrostatic gun and subjected to an electric field associated with the

difference of potential between parts connected to ground (- polarity)

and gun (+ polarity). This method allow to have a high transferefficiency, savings in product cost and time, a thin and uniform layer.

Impregnation station (requires a small amount of penetrant thanks tothe draining operation and allows a complete wetting of complex

geometry parts).

TopicSheet

P02


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Accessories and devices for qualitycontrol for manual inspection ofpenetrant testing

Accessories :

Penetrant excess removal:

Solutions to remove penetrant excess: air-water gun, water spray,paper towels, rags ...

Drying before developper application:

Drying means used: heat gun, drying oven, compressed air, dried andlint-free rags.

Display solution:

White lighting. UV lighting (fluorescent penetrant testing).

Devices for quality control:

Lux meter and UV radiometer (allow to ensure that control is carried outunder standard lighting conditions ).

Plate panels for penetrants sensitivity characterization andcracked blocks (allow to check bathing and penetrant quality used overtime).

UV stereoscope (mainly used for counting indications revealed onspecimens).

TopicSheet

P02



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Penetrant Testing

Products used for penetrant testing present significant risks to the operatorand the environment. These products are:

In general flammable (organic products) and explosives (spray cans). Toxic to the aquatic environment. Hazardous to health operators (must not be inhaled / ingested or in

contact with eyes or skin). Usually contain volatile organic compounds (VOCs) with potentially

greenhouse effect.

In general, the penetrant testing operation produces a large quantity ofwaste (effluent, rags, empty cardboard packing).

Ecological impact of penetrant and magnetic particles testing in France peryear:

100 000 tons of organic products. 200 000 tons of waste. MkWh 1000 is 200 million tons CO

2equivalent.

In Europe : these figures are multiplied almost by 10.

Environmental challenges and objectives of the Green Testing project:

Reduce environmental pressures (energy consumption, greenhousegases and VOCs emission, waste production by 20% to 30%), thepotential risks to operators health and the tasks arduousness.

Reduce drastically inspection costs (from 20% to 40%). Reduce environmental pollution (by 90%) through the provision of

alternative technologies.

VOCs are the cause of the ozone layer destruction. The ISO14001 and the related European Directives, lead each firm toreduce its VOC emissions.

The implementation of penetrant inspection required large quantities of

energy particularly for drying parts.

Constraints and environmental risksTopicSheet

P03


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Risks related to UV radiation:

Aging and skin cancer. Eyes problems(cataract).

Indirect risks:

Risks associated with handling parts (parts dropping, fingers jamming). Burns risks (drying equipments and hot parts).

Electrical hazards :

Electrocution hazards due to the use of both electrical sources (lightsfor example) and water simultaneously to achieve the penetrantinspection.

Risques of explosion due to spray cans:

Care must be taken when using aerosols near direct heat sources(welding, hot parts, for example) because of the flammability ofmaterials used and the risk of explosion of spray cans.

Risks related to vapors exposure of penetrant materials (solvents andorganic products):

Exposure to solvent and organic product vapors is deemed hazardousto health.

TopicSheet 03

Risks for the operator associated with theimplementation of penetrant inspection



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FactsheetApproach to reduce the environmentalfootprint of the penetrant testing

Ressuage

04

1

To manage the environment in everyday life:

Generally speaking, companies must invest in a policy of proactive protection, for

example by setting up an environmental management system (EMS).

The eco approach within the company has been built according to a structuredset of steps and controlled at every level of their implementation.

Making an environment diagnosis : Waste diagnosis: waste management by controlling the processing

costs, waste reduction and establishment of a sorting and selective

collection at the source ... Energy diagnosis: hunt wasting; energy saving solutions, energy

recovery solutions (heat). Gaseous and liquid effluents diagnosis: optimized choice cost /

performance of the treatment system ; reducing the amount of effluentat the source ; reusing treated wash water; recovering excess of usedmaterials.

Other possible diagnoses: dust and particles; odors; noises.

To inform and educate the different agents or stakeholders

Monitoring: nuisance registry to record incidents occurred and responsesrelative to the environment feedback.

TopicSheet

P04


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Approach to reduce the environmentalfootprint of the penetrant testing

To reduce incomings and outgoings:

In every industrial process, all incoming and outgoing parts have a greater orlesser impact on the environment, that it is necessary to minimize as possible.

The incomings:

Cleaning products. Products required for the implementation of the penetrant testing

process (penetrant, developer). Electrical energy required mainly for drying operations. Water used for cleaning operations and for penetrant excess

removing.

The outgoings:

Wastes (cartons, empty spray cans, rags and papers, damagedcontrol equipments : UV or white lightings ,).

Sewages and residual cleaning products contaminated by organic orsolid debris (penetrating and developer products, residual oil and

grease).

Other possible nuisances:

Odors caused by chemicals used or from effluents (air extractor)treatment plant.

Noise due to control devices (ventilation noise of penetrant testingline and drying ovens or drying guns blowing hot air).

Noise due to the handling parts in production control plant (falling ofparts in the waste good containers at the end of the testing line of

control for example).

TopicSheet

P04


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Practices to minimize risk of accidentsand impact on operators health

TopicSheet

P04

Solutions to reduce risks of accident:

Collective protective equipments:

Ventilation and purifying atmosphere at the workplace. To delimit / or mark the access to dangerous areas. Protection by recording a dangerous function during interventions. Identification of dangerous products to prevent inadvertent use. Hazard signs To delimit work areas.

Personal protective equipments:

Safety shoes and helmets. Goggles. Gloves, protective clothes.

Masks and breathing equipments. Hearing protections (falling of parts in the scrap good containers at the

end of the testing line for example).

Give a sens of responsability at the operators :

To take into consideration the user sheet of chemical products (byreferencing to the company doctor who has at disposal the health andsafety).

To know the location of the fine extinguishers and their functionaryuse.

Dont leave tools or parts on the ground in the workshop. To keep working equipments and accessories at their place and

clean the working place.


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Improvements for a greener manualpenetrant testing

Lighting systems:

Preferred LED lamps (white light or UV) to conventional bulbs: Greater light intensity. Energy consumption 50 times smaller than for mercury vapor lamps

(2.5 W instead of 100W). Longer life (over 10,000 hours). Less hazardous waste to the environment (especially mercury vapor

lamps UV lamps).

Penetrating products:

Purchase products in bulk rather than spray cans:

Diminution of the quantities of packaging and aerosol cans.

Give priority to water-based products rather than organic-based products:

Reduction of VOC emissions. Non-flammable products. Effluent treatment simplified and maintenance costs reduced (low

fouling).

Eliminating the inherent risk due to the use of organic solvents(harmful vapours, skin irritation, ...). Make easier removal of penetrant excess by water easier.

To prefer electrostatic processes: although expensive, they allow the reductionof quantities of products required for the penetrant testing operation.

Spray systems:

Preferred rechargeable spray systems (with an adapted spray nozzle andmechanical pressure by pumping):

Waste quantity reduced. Quantity of PT products reduced by 4 compared to the use of an

aerosol. Does not require gas propulsive.

Ecologic inspection

products

TopicSheet

P04


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Improvements for a greener manualpenetrant testing

Drying systems:

Preferred drying systems which consume less energy: Drying by infrared lamps for example, which can complement the

usual drying systems (oven and air oven).

Effluent recovery systems :

Using cleaning fountains with recycling of cleaning products by debrisfiltration:

Reduces the amount of solvent required for cleaning.

Use of recovery equipment and wastewater filtration (activated carbon): Prevents the spread of effluents into the environment and allows their

treatment.

Use extractor hood and filtering systems of organic vapors: Prevents the spread of toxic vapours into the atmosphere. Protects the operator against toxic vapours inhalation.

Ecologic inspection

products

Penetrant testing stations:

To prefer penetrant stations use, promoting the implementation of theprocess and reducing risks significantly:

Recovery by draining parts. Parts handling easier. Opportunity to recover heat from drying ovens.

Work stations are generally autonomous and equiped with a hood.

TopicSheet

P04


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