Penetrant Testing Questions and Answers NDT

dp test
Written by writerchetan

You are reading this liquid penetrant inspection article on our website jobandcareer.in, In this, important liquid penetrant testing questions and answers are given related to Penetrant testing which is asked in dye penetrant inspection job interviews,

On the Non-Destructive Testing page of this website, you will get information related to NDT methods and updates on new NDT Jobs,

All the worldwide NDT jobs related to NDT are updated on jobandcareer.in, you can see new NDT jobs update by joining our telegram channel link given below,

Dye penetration test for welding

This is an NDT method that is done everywhere after visual inspection, in which defects are found on the weld, material, etc. from liquid penetrant, it is also called dye penetrant weld inspection,

Here you will find questions and answers related to dye penetrant tests which are mostly asked in liquid penetrant testing ndt jobs interviews,

penetrant testing questions and answers

Penetrant testing

Q1 What is penetrant testing?
It is a nondestructive inspection method in which open-to-surface discontinuities are detected in solid and non-porous materials, etc.

Q2 What is the principle of PT?
The principle of this NDT method is the capillary action on which this method works,

Q3 What is Capillary action?
The penetration of a penetrant liquid dye into a material in a compressed space or the travel of a penetrant liquid from one location to another is called capillary action,

Capillary action is a characteristic of any liquid with which it moves, the motion depends on the cohesive forces of a liquid, adhesive forces and surface tension of the liquid, etc.

liquid penetrant inspection

penetrant of different colors is used in the Dp test, hence it is called liquid penetrant inspection,

Q4 Why do dye pen test?
In this method NDT technicians can find defects and discontinuities from the material surface without any damage to the materials, so used this method.
This method mostly found the open-to-surface discontinuities from the material surface, so used this method widely.

Liquid testing has its advantages over NDT methods due to which it is widely used, it is a low cost, portable method, and this method can be easily performed on all objects from small to large,

Q5 On which material can the Penetrant test be done?
The liquid Penetrant test can be done on any ferrous and non-ferrous materials, solid and non-porous materials, for example, ceramics, plastics, glass, iron, etc.

Q6 On which object Dye Penetrant testing cannot be done?
The liquid penetrant test cannot be done on any porous material, object because that object absorbs that penetrant liquid and due to which capillary action is not possible, Example: Rubber, Wood, Paper, etc.,

Q7 What is open to surface discontinuities in liquid penetrant?
The cracks, laps, porosity, pinholes, shrinkage areas, laminations, and similar discontinuities on the surface of a material are called open to the surfaces discontinuities,

In other definition, the mouth of any discontinuities is open on the surface of the material, in which we can see some discontinuities with our eyes and some discontinuities cannot be seen with the eyes, for that penetrant test inspection is done,

Q8 What types of materials can Liquid PT be done on?
It is used for the inspection of ferrous and non-ferrous metals, cast products, metallurgy parts, ceramics, plastic and glass articles, etc.

Q9 Which has higher sensitivity in dye penetration test and Magnetic Particle Testing?
The penetrant test has higher sensitivity than the magnetic particle test,

Q10 What is the biggest limitation of the pt ndt method?
This method can detect only open to surfaces discontinuities on a material, if any discontinuities are closed on the surface of the material then those discontinuities will not be found in this method, for this another method of NDT has to be done on the materials,

Q11 How many types of Penetrant are there?
It is mainly divided into two parts (type-I, fluorescent, and type II, visible), Along with this, according to Penetrant Removal, it has also been divided into four parts,

Q12 What is Penetrant?
It is an organic liquid mixture that acts on capillary action and is available in different colors, it penetrates deep into an object, hence it is also called Penetrant Testing,

Q13 How many types of Access Penetrant are removed?
In this, there are four main ways to remove Excess Penetrant, which include Water-Washable, Post Emulsifiable Lipophilic, Solvent Removable, Post Emulsifiable Hydrophilic,

Note: In Post Emulsifiable, Lipophilic and Hydrophilic are called by some technicians, inspectors, etc. Only Post Emulsifiable,
You can tell the types of Excess Penetrant removal according to you, but the removal of Excess Penetrant is mainly done in four ways,

Q14 How many types of Emulsifiers are there in Liquid Penetrant Testing?
Emulsifiers are divided into two parts, which include Hydrophilic emulsifiers, and Lipophilic emulsifiers,

Q15 What is the process of the pt welding test?
The first step in the DP test process is Pre-cleaning or Surface preparation, Penetrant application, Removal of excess penetrant, Developer application, Inspection, Post-cleaning,

Note: While giving the interview, you can tell the above-mentioned Penetrant testing process in response, while doing Penetrant testing in a company, follow the Penetrant testing procedure of that company,

The penetrant testing process has to be done according to the procedure and every company has its own separate procedure in which dwell time, developing time, etc. is given,

If the person in front is not satisfied with your answer, then you can say that the Penetrant testing process is done according to the practical performance,

in which – Pre-cleaning or Surface preparation, dry time, Penetrant application, Dwell time, Removal of excess penetrant, dry time, Developer application, Dwell time, Inspection and Post-cleaning

Q16 Why Pre-cleaning or Surface preparation is required in Penetrant testing?
Pre-cleaning or surface preparation is done to open the discontinuities mouth on the surface of the material and the object, so that the capillary action is easily done in this method,

Q17 Who Creates Penetrant Testing Procedure?
Liquid Penetrant testing procedure Creates by ndt level 3 of the company, Which is made keeping in mind the company’s product, clint requirements, ASTM, ASME codes and standards, etc.,

Q18 Can a procedure be changed after it is created?
Yes, the Procedure can be changed as per practical demonstration, and requirements.

Q19 What is pre-cleaning or surface preparation?
This is the first process of dp test, in which care is taken while doing pre-cleaning or surface preparation that there is no oil, dust, water, visually points other contaminants, etc. on the surface of the material,

Q20 What is the dry time?
After pre-cleaning and removing excess penetrant, this time is given so that further process is easy, most of the drying time lasts 1 to 2 minutes and depends on the object size,

Note: Dry time mostly comes while pre-cleaning and removing excess penetrant, so it is not written separately in the procedure,
This dry time is given by cleaning the surface of an object with a solvent-based cotton cloth and removing excess penetrant,

Q21 How is Penetrant applied?
Liquid Penetrant dye is applied to the material by brush, spray, etc., if any component is of small size, then the penetrant application is done by dipping it,

Q22 What is Dwell Time?
Dwell time is the time in which the liquid penetrant dye takes capillary action or reverse capillary action in a material,

Note: This Dwell time is mostly 5 to 30 minutes and according to the company’s Penetrant testing procedure etc.,
This time is given after penetrant application and after developer application,

Developer application is done after removal of excess penetrant, it is called developing time, which is also called by some ndt technician dwell time,

Q23 How many types is the sensitivity of penetrants divided?
In penetrant testing, the sensitivity of penetrant is divided into Levels – Ultra Low Sensitivity, Level 1 – Low Sensitivity, Level 2 – Medium Sensitivity, Level 3 – High Sensitivity, Level 4 – Ultra-High Sensitivity,

Q24 What is sensitivity in fluorescent penetrant testing?
Sensitivity is the ability of a small indication to appear in the dark area and relative background at its maximum, it depends on the penetrant liquid material, the object property, and the eye of the inspector.

Q25 How many types of developers are there?
the developer has been divided into six forms – Dry Powder, Water Soluble, Water Suspendible, Nonaqueous Type 1 -Fluorescent (Solvent-Based), Nonaqueous Type 2 -Visible Dye (Solvent-Based), Special Applications.

liquid penetrant testing ndt

Many types of dp test material are used in penetrant testing methods, in this method the material is selected according to the dye penetrant test procedure,

penetrant testing questions and answers

penetrant testing questions and answers

Q26 What should be the light intensity in visible penetrant testing?
minimum 100-foot candles (1000 Lx) required, it may be changed as per ASME code and standard revisions so check the latest update of revision.

Q27 What type of color penetrant is used in visible penetrant testing?
Most of the red color is used in visible penetrant testing because discontinuities can be easily seen by the eyes in the white background of the developer,

Q28 What should be the black light intensity in fluorescent penetrant testing?
minimum 1000 μW/cm2, measured at a distance of 38cm (15 inches) from the outside face of the filter, minimum 2 foot-candles (20Lx).

Q29 What type of light is used in fluorescent penetration inspection?
In this ultraviolet light (UV light) is used,

dye pen test

To do this dpt test method of NDT, the code, standard, accept and reject criteria, etc. made by ASME are followed,,

Q30 In which article of ASME is given about Liquid Penetrant Testing?
Given in article 6 and article 24 of Asme sec. V.

Q31 What are the acceptance criteria for Liquid Penetrant testing?
ASME BPVC Section VIII, Div 1, Appendix 8 which is to be followed while performing this method on weld, acceptance, and rejection of indications accordingly,

Note: read reference code for more details of acceptance criteria in DPT., The acceptance criteria for the production product, and material in the company are decided according to AWS, ASME, ASTM, etc.,

Q32 What are the code and standards for penetrant testing?
code and standards are ASME BPVC sec. v, article 6 and article 24.

Q33 Can two different company brand materials be used in Liquid Penetrant Testing?
In Dye penetrant inspection, brand material of the same company is used, as the chemical composition, liquid molecules, dwell time, capillary action time, etc. are different in the penetrant and other materials made by the company.

dye penetration test

The Dye penetrant test is done in every company, from small to big, to find out the open to surface discontinuities of the material, this question and answer will be useful for your NDT jobs and for your knowledge,

More penetrant testing questions we will update here below as soon as possible, subscribe and follow our website for new updates.
YouTube channel – click here

Final word

This penetrant testing question answer is written as per general information for ndt technician, inspector, engineer, etc.,

Join Telegram Channel – click here

The information given on jobandcareer.in is only according to educational and penetrant testing questions asked in the NDT interview, we are not associated with any NDT institution, ASME, ASTM, etc. organizations.

About the author


Engineering, Technical, share market and make money online contents and Books writer.

Leave a Reply