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Matthew Petroleum Notes

AWKWARD TECHNICAL INTERVIEW QUESTION
ANSWER THAT…. IF YOU CAN

First of all, let’s get one thing straight. This is not about the old ‘tell us about yourself’ or ‘what is your most significant achievement’ - type of interview questions. Have a look at the end of this short article if you want to know about those platitude-inducing examples of mutual timewasting. These questions are about technical subjects, which is what asset integrity jobs are all about. It’s worth thinking about how you, personally, would answer the question, before you look at the answer suggestions.

Here’s your tricky interview question. It should be of use to you if you are an employer or a job candidate. The questions vary in subject as this website is regularly updated but always centre on the technical subjects of Asset Integrity

This week’s subject; DAMAGE MECHANISMS and their (un)predictability

Question: Which damage mechanisms (DMs) from API RP 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry would you consider the most unpredictable, and why?

questions and answersWhat’s the idea behind this question?

Well, API RP 571 is 250+ pages long and contains about 65 Damage Mechanisms (DMs) depending on how you count them. API RP 571 is an excellent summary of metallurgical and corrosion engineering knowledge; if you want to be involved in the higher positions of the asset integrity industry you need to know about it. This makes it good technical interview material. Each DM is covered separately in 3-4 pages which are easy to read and provide details of the predictability of each DM, based on material susceptibility, critical process factors, inspection methods and ways of mitigating the effects.

Here’s some typical ‘unpredictability’ points (from the 65 DMs) that could be put together to form an answer:

  • Mechanical fatigue

High unpredictability owing to the rapid propagation of cracks once initiation has started. High cycle fatigue is particularly unpredictable due to the difficulty in determining the number of fatigue cycles that have occurred.

  • Wet H2S ‘sour’ service corrosion

Corrosion rates are a complex combination of material susceptibility and the concentration of the process. The form of the DM can differ depending on temperature, erosive effects and local concentrations. The most unpredictable situation arises when the specification of the material is either unknown or variable.

  • Corrosion under insulation (CUI)

This in one of the most unpredictable DMs. It frequently occurs outside the API 571 temperature range (-12 to +175 deg C) for plain carbon/low alloy steels, particularly when the temperature is cycling. In practice it is also very difficult to eliminate all areas of damaged pipe lagging and water ingress on old plant. Operators are sometimes reluctant to remove all lagging from a system, allowing CUI to progress underneath it.

  • Creep rupture

Theoretically, creep rupture of high temperature components is a predictable DM which progresses through 3-4 identifiable phases. In practice it is very susceptible to temperature distributions and upsets in a component; a 40-50 Deg C increase can result in large reductions in the creep life. Creep can be identified using metallographic replication techniques but once it reaches a certain stage, failure can occur unexpectedly.

As an Interview Candidate, you really need to mention no less than four DMs to show your knowledge of the subject. The ones shown above are the easier ones; they could be considered ‘general knowledge’ in the world of DMs and so may not impress higher-level technical interviewers based in refineries. There’s many more (better) ones in API RP 571; all you have to do is go and dig them out.

 

OK I promised at the beginning to discuss those ‘other’ types of interview questions so here we go:

Wild goose chase questions and platitude answers

 If you are an employer, you will sooner or later land on the idea of using some well-worn ‘stock’ questions to help you run candidate interviews. These come under several named categories; ‘open-ended, ‘motivation’, ‘personality’ or ‘focus’ questions, just to name a few, and are loved by non-technical people who use them all the time.

Why do you want this jobIn practice, these wild goose chase questions (let’s call them that) sound quite clever but are actually comfortably easy to answer by simply using a few platitudes.

Assuming you haven’t looked it up recently, a platitude is a, meaningless, or prosaic statement, uttered as if it were fresh or profound. In an interview situation they are a super way to answer a question by dispelling the interviewer’s unease. They work wonderfully well in spreading a shallow, unifying wisdom over a difficult topic.In reality however they are generalized, overused and undirected statements with ultimately little meaningful contribution towards a solution. A platitude is a terminator of useful thought.

There’s probably 10-15 of these goose chase questions around in common use, beleaguering employment interviews and annual appraisals with their presence. Let’s look at a few of them, and how they encourage platitude responses.

Question for job applicant: ‘How do you manage your time and prioritise tasks?’

(Ok, time for a platitude); ‘I manage them according to the job in hand, looking at the current situation and prioritising them as necessary for the benefit of my employer’

 ‘What is your biggest weakness?’

(Oh goody, it’s that one, let’s roll out a platitude); ‘I gauge others by my own high standards’

 ‘Where do you expect to be in five years’ time?’

(Yesssss… platitude Nirvana); ‘Working for you and just being myself’

Here are some others, so you can prepare for them. They’ve been around for years so are no big deal; check the internet for lots of suitable answers. Don’t forget your platitudes.

‘Tell me a story’ … (watch out this can be a dangerous one)

‘What is your most significant achievement?'

‘What motivates you?’

‘Give an example of a time when you showed initiative.’

‘Give an example of a time when you handled a major crisis.’

‘Why do you think you will be successful in this job?’

‘Give me an example of your lateral thinking.’

‘Have you ever had a bad experience with an employer?’

‘If we shrunk you to the size of a grain of rice and put you inside a pressure vessel, how would you try to get out?

Serious note for technical interviewers

The types of questions above appeal to many people asked to take the role as interviewer. They work, to some extent, but seriously underestimate the ability of people to tell you exactly what you want to hear. The platitudes you receive in response to questions like this can be very convincing. They tempt you not to dig further, but just move quickly onto the next one, to bypass your own discomfort. After all, if you were truly comfortable with assessing candidates’ abilities, why would you need to use pre-formed goose-chase questions like these? Use them with care, if you want to be taken seriously.

We offer a TRIAL TECHNICAL INTERVIEW

If you want to check your knowledge for a specific job role in the integrity industry then try our trial technical interview.  Its purpose is to test you on the technical aspects of the job you are thinking of applying for.  There's no time limit on it but expect it to last at least 20 minutes.  After the discussion we'll give you honest feedback on how you did.  Just let us know the type of position you are going for; we'll do the rest and respond with at time slot for you to call us.

There's no charge, but we will expect you to call us at the allocated time and be ready to answer technical questions.

Remember your trial interview is on a purely technical subjects.  We are not interested in you personality traits, do-gooding activities or any wonderful extra-curricular interests you may have.

Technical Interview

TRIAL TECHNICAL INTERVIEW

CONTACT US Tel: 07746 771592

help@matthewsintegrity.co.uk

Matthews Integrity Training