November 17, 2021
Understanding Induction Bending and its Applications
So welcome everyone to this fifth
Livestream of EngineeringTrainer.com.
My name is Luuk Hennen.
I'm the founder of EngineeringTrainer,
and today I will have a conversation
with Sondre Luca Helgesen,
who's the CEO and founder
of Stressman Engineering
and with Øyvind Storehaug, who is the
business development manager of NIRAS.
A world leader in the production
of Induction Bends.
We'll be covering the topic of induction
bending, what it is, how it compares to
welded bands and how they can be applied.
And I think the topics that we will
address during this conversation will both
be interesting from a piping design
point of view, but also especially
from a pipe stress point of view.
Before I move to the speakers, let me,
first of all, welcome all of you who are
watching this stream to the session.
It's a delight having you and I actually
want to invite everyone who's watching
this to participate in the chat.
So as a first invitation, I invite you
to let us know what your location is.
That's always a good ice
breaker and good fun.
Let us know where you're from
and from where you are viewing.
Obviously, I want to invite you all
to connect with me with Sondre,
with Øyvind on LinkedIn,
just to connect or to start a conversation
and to consider subscribing
to the YouTube channel.
If this type of content
is relevant for you.
Having said this, Sondre, Øyvind,
welcome on board.
We are honored to have you, of course.
How are you both doing?
I'm doing fine, thank you.
So we just organized the whole setup and
I'm really happy with it and that you
could both join us from the
location of Stressman, Norway.
Before we move to the slides,
just a quick brief introduction.
you've been involved with Induction
Bending for quite a while at NIRAS.
Since how long have you
been working at NIRAS?
I've been working for ten years,
but I've been working with Induction
Bending since 1983, so I've been into the
business for almost 38 years.
So a lot of experience with piping.
And I'm happy that you could join us
for this conversation.
Sondre and I,
we are connecting on a regular basis
and discussing loads and loads of topics.
So it's nice too,
now that we're doing this live stream
about the Induction Bending that you were
able to join us,
I actually think that's great.
We see all kinds of messages coming in.
So people, Martin watching
from Netherlands, Tara from Singapore,
Alma from the Philippines, we got London,
we got England, we got Spain.
Thank you, Kokan.
So, as I mentioned, it's a delight
having you all on board for this stream.
And I do invite you to share your
thoughts, ask questions in the chat.
It will really make this session a lot
of fun if you participate actively.
Having said this,
we will now switch to the slides
that will guide our conversation.
So here we got the slides Sondre!
Take it away.
I'm going to do that.
So as you already introduced me.
I'm the CEO of Stressman
Engineering. And at Stressman we like to say
"Relax, let us handle your stress."
So I've been doing this
for about ten years.
I'm not as old as
Mr. Øyvind here.
So I was one year old when he started
working with Induction Bends.
But we have known each other.
We have known each other
for quite a long while, actually.
we've done so far about 370 projects.
It's within all fields,
all kinds of different industries,
oil and gas, maritime,
land-based also in the energy sector.
And it's basically numerical analyzes.
Give us a problem.
We'll solve it with the laws
of physics and computational power.
I don't talk too much about
exactly what you're doing today.
Today we're going to talk more about
which is a very interesting topic that
there is a lot of, call it urban
myths about it because it's
a topic that's kind of easy to understand.
But at the same time, it's
encouraging a lot of questions to it.
For the past, I would guess like 15 years
we've been working together because we've
been doing the calculations and Øyvind
has been Bending the pipes, not himself.
But he got up at which is a small town
like 40 minutes away
from here, quite close.
So we are from the same
district of Norway called Telmark,
and there is a lot of industry here.
So it's actually
an interesting place to be.
So I don't know if you want to say a few
words about NIRAS just very briefly.
NIRAS was established in 1955.
So we have a long time in the business.
Almost all the people coming
from a machine dealer called Bombak,
starting with the Induction
Bending machines in 1983.
So today we have a five Induction Bending
machine and we are Bending at 20-inch and
we can handle wall thickness of
up to 100 millimeters.
We are much into high pressure,
high temperature area for replication.
Quite big pipes as well.
As you always say, it's not about size,
because most of the pipes that are high
pressure, high temperature
is not 30 inches 40 inches.
But it's a lot of, like,
six-inch piping, eight-inch, ten-inch.
And so on.
I think about 90% of the pipe is
from nine or eight inches and down.
So the big volume is below 20.
That is a big number.
And as you say, it can bend up
to 100 millimeter wall thickness.
That's about four inches.
But our last machine
was going to OD 125 millimeters.
So there is a big volume for us
for high pressure, high-temperature piping. And we are much into super duplex, duplex and all these materials.
That is our speciality.
And these are some of the companies
who actually use Induction Bending or
Induction Bends in their facilities,
in the process plans, in their
A lot of people I meet at least never used
Induction events in their designs before.
So it's just to show that there is a lot
of end users who have induction
bends in their systems.
We are a supplier.
But the first Induction
Bending machine also designed and built in 1964 so
of course, a lot of Induction Bending
pipes around in the world, but still
the big volume is waving stand available.
We're looking very much to come into the
sector, both top side and subsea.
What would you say
before we dive into the technicalities
of Induction Bending, et cetera, what
would you say is the market share?
Is there, like, an estimate
you could make? The market share between
Induction Bends and Standard Bends?
like welded bends
I'm not sure.
But I think maybe 0.1% of the Induction pipe.
And the rest is standard welded elbows,
almost 200 year standardized
way to make pipelines.
We have a big market if you could get
a bigger share of the market that people
are going away from welding and elbow.
But, for example, subsea applications
that we see here in Norway, they are
quite good at using Induction Bends.
And of course, the Norwegian Equinor our
supplier is very happy
to use super duplex.
We are very happy
for every super duplex coming up.
Of course, we have many club pipes
and carbon steal and whatever.
But we are very happy for our project, for subsea pipelines and
of course, high pressure, high
temperature to avoid welding.
This talk today is more about
understanding Induction Bending.
What is Induction Bending?
How do we apply it in the design and how
do we do the calculations of it?
That's what we're going
to talk about here today.
What this Induction Bending? It is going to be
just a very quick crash course
into Induction Bending.
Basically, it's not going
to be all the details.
This is a speciality in itself.
How you actually do the work
that you are so good at.
As you can see in this picture here,
there is the heat affected zone
that's being heated up to around 150 could it be for super duplex
and 900 degrees for carbon steel?
So we have a very good control over
temperature and the trenching.
So we are almost doing the heat treatment
for super duplex when we are doing it in the bending machine.
What I really enjoy about this picture
is really also it's very local heating.
At least that's what it
seems from this image.
Interesting. What people are
saying is with regards to ovality.
A lot of people are concerned about
ovality that when you bend the pipe,
it's not going to be a circle anymore.
It's going to be more like an ellipse
This is very local heating.
Very local and the thinner the heating zone is, the more cold circle
material we have on both sides.
And that keeps the shape around.
very often, almost for every project
for a subsea we have to do pigging
and it could be 97% of the nominal ID.
So it could be very tight
to the original pipe.
So I think sometimes the pipe could be
more out of roundness
than we could make into the pipe.
So basically what is happening is
that a part of the pipe is being heated up
and then you have an arm that's
not shown so well in this picture.
But there's an arm that is bending
the pipe, and then you have cooling
or crunching, as you said over here.
And that was a very brief
introduction to it.
As you also mentioned,
sometimes if you have very big wall
thickness or big wall thickness, you
need to do post-heat treatments on it.
And again tempering for carbon and carbon steel.
So we have the metallurgists,
we have the Induction by the machine and we have
the heat treatment furniture
to give us the right quality.
So here we could
do the heat treatment in the Induction
Bending machine itself,
up to 25 millimeters for super duplex.
So then we could avoid the possible heat treatment after bending.
But the bigger question
is why Induction Bending?
If you see, for example, this FPS over here,
the process facilities here are huge.
So there's so much piping.
And as you said earlier,
most of this is not Induction Bends.
It's standard bends
that are welded into place.
So by switching to Induction Bends,
how do you say it? It would be optimized
with regards to cost delivery time?
Also, it could have
an impact on the weights.
It helps on the pressure drops.
It makes your systems more
And also it will help on the erosion.
So Sondre, costs would mostly be affected because you
simply reduce the number of welds, right?
That's the main thing,
as you can see in the next picture here,
this is what we call
a flow loop or a spool.
In this case,
as you can see here,
this is what they call the nearest loop or
the nearest spool I mean and it is a
one piece that's bent all in one process.
While the original would
look something like this.
If you're only going to have 90 degrees
and 45 degrees bends,
it's going to look like this.
And here we got 1 2 3 4 5 6 7 8 welds.
While this one, you don't have any welds
between point A and B on the loop.
And then if you compare the two floor
loops together or two spools together,
they're almost the same.
A lot of people are saying that this 3D
bend radius is taking more space
than one and a half D bend radius.
So yeah, it takes a little bit more space,
but not too much space either.
Just a cost comparison between
the two different spools here is that,
as Øyvind was saying,
there is a lot of things going into this.
So if you buy
piping from one vendor with the same batch
number or heat number,
and let's say you make ten spools.
For a six-inch pipe schedule extra extra
strong, you can save up to 66% in cost.
If it's a small pipe, a two-inch
then it's 61%.
For example, another thing that is very nice
is that when you're designing
you can start to use your imagination
because the Bending machine
can bend in all directions.
It's not like you need to do one by one
bend or something like that,
you can bend in all directions.
So by looking on this spool here,
if it was standard bend, you will
have 1 2 3 4 5 6 7 8 9 10 11 12 welds.
On a regular piping system.
This one, I don't know how much time
you use to bend the pipe like this.
I could take about 20 minutes for every
bend, but you don't have to cut the part.
You don't have to order the bends.
You don't have to have the lineup bending,
welding, welding complication.
And you save a lot of documentations.
But another issue is that we always
can give your attention before the bend.
So you can get to the welding area, away from the interzone.
Just from my understanding,
just to be absolutely clear,
this obviously is a little bit of a dummy
question, but we see the bands
here and different colors.
But this was like
a straight piece of piping.
And now we see these bands
because those were heated.
That's what colorized.
What changes the color, right?
In the beginning, it was
a long pipe with this color.
And then when it's getting
bent with induction heat.
Inside, we use the gas
to reduce the oxide.
So we don't have the same side.
So this is a bend.
We don't have any welds at all.
Typical seal we have the heating zone
have been attached to the pipe.
We got a few questions, and I think
some of these are nice to just
So is there a minimum bend radius, Øyvind?
So the minimum physical bending
radius for machines is 65 millimeters.
But very often you have a specification
who limits the wall thinning in the outer
wall of the pipe to be example
12.5% on the middle dimension.
So that is normally what we have to follow
to give our customer
within this publication.
But we can talk a little bit later about this.
People are a little bit
scared about the thinning of the pipes.
That is our limit.
So that's the reason, we are saving what increased the radius
because we ask people to use
the same batch and line pipe for
both the straight section
as the bend sections.
You don't have to waste
money to buy more expensive
line pipe for the bend section.
The limit is a little bit more what
the customer has
for requirements to the whole thing.
So that's interesting.
Thanks for answering.
We already have a few questions
that jump straight in.
Like what about the sieves and
stress analysis. We'll get there.
I'll reserve those questions for now
for those who ask them,
and I'm confident that they will
be answered a little bit later on.
Sondre, feel free to continue.
So also the next picture here.
It's just a different way of reading it.
For example, instead of going, we are going all this
from a simple pipe from A to B.
So in this case, it's one,
two, three bends in between here.
We got six welds on it.
So one way of doing this
could be taking one long
line pipe and bend it with two bends.
So you get from A to B.
Of course, there could be
some limitations on this.
Maybe you need to have a bit more
flexibility due to stress, for example.
But there is a lot of
ways you can route it and you're
not tied up with the conventional
bends and fittings.
That is normal.
Get creative. Could be very hard
to make the spool without any weld.
Then you can cut it in the middle
of the stripe section.
And maybe you can ask for get a little
more over length in this
section so you can
get one weld compared to six.
So anyway, you will save time and save
money and make a more safer system if
you need to have one weld for adjustment.
If you want this kind of routing,
you could bend these bends as well.
Yeah, from the other pipe.
With regards to weight, for example,
you can optimize your routing basically
to save weight on a project
you can easily get from A to B,
in many cases.
something that the end user is
typically very worried about.
So if you have a lot of pressure drop
in a process plant, for example,
or anywhere, basically,
you need some energy to pump it along.
For example, if you have a 1D bend rate,
this is this bend that you see here going
to a 3D bend,
you get a reduction of the pressure drop
through the bend with a ratio of 48%.
So if you go from 1.5D to 3D
times the radius, we still drop.
Maybe not as much as 48, but at least it's
22% and over 20 years, maybe 30 years.
That could be a lot of money in the end.
And also that's energy saving.
And that's what we need
to do in the future.
We define ways to save
energy to get a cleaner future.
So this is also, that's a fair point.
And then similar
to the pressure drop
it's the erosion that can occur if you
have particles, for example,
in your flow that might erode your pipe
on the inside, then increasing the radius
will decrease the erosion rates.
That's another good thing
to use Induction Bends.
Because if I remember correctly,
Sondre, you once stated that
the angles that you can
basically make are completely free.
You can do, like, 72 degree bend.
If you would want to.
Yes, you can have a 1.5 degree bend or 3 degrees bend.
It would make the design
process a lot more creative.
I would love to do that.
I think some one said they have, like,
88 deg or 87 degrees angle instead of a 90
degree because they were going
to be used as sloped system.
but back to the design of the pipeline.
So it's the point A and B,
So maybe if you have the role that you
want to have 90 degrees and it's here
to hit the endpoints,
maybe we have to bend 92 degrees.
It doesn't matter so much
if the issue is 88 deg or 92,
the most important is that the end
point of the pipe is going
to be in the right position.
Yeah, but we can be bending in 0.5 degrees
accuracy, so that's no
problem with the induction bending.
Then you have spring back on.
So this brings us into the last
part of this session is okay.
This is how you can use it in design.
And if you're going to use induction bends
in your design,
there's always going to be a lot of questions
popping up with regards
to how can I calculate those?
Today's session is based on B31.3. But
first, let's take a look
at the wall thinning effects.
So as you can see here,
actually, I don't know if you can see it
very well, but we got chopped up
Induction Bends in our office,
of course. It's actually
been several times to
Singapore, its been traveling the world, this chopped up bend.
I didn't mean to skip the slide.
I'm sorry about that.
There we go.
So as you can see here,
the inside is getting thicker
and the outside is getting thinner.
The neutral line, as you like
to call it, it stays the same
and the metal doesn't
disappear or add to it.
So it's going to be the same amount
of metal around this cross-section here,
which is good, because then the sectional
modulus is going to be about the same.
And then I took this picture.
I went into Photoshop and I colored it so
that it was easier to see the thinning
effect that you can see here.
And then we had a thickening
effect over here.
We can calculate that very accurately.
It's not a problem to anticipate
what it's going to be.
If you know the wall thickness before
bending, we can find out what is going
to be after bending with a very
high accuracy. And how to do that?
And also, this is a white paper that's
available on our website as
its made together with NIRAS.
It's free of charge, just download it.
You don't even need to register at all.
I'll make sure to put the link
to that white paper in the notes
of this video on the YouTube.
Yeah, that'd be good.
So basically what I like about this, you
managed to simplify formulas quite a lot.
So to find out,
either you can define a wall thinning or
thickening in percentage or basically
calculate the new thickness if you
have the original wall thickness here.
Sorry to interrupt.
Time is flying.
Obviously, maybe let's not go
into the details of the actual formulas.
If people want to look into them,
they can download the white paper.
But let's discuss the numbers
and the conclusions.
You just take a look at the white paper
and you will have a better
understanding of the thinning effect.
I think what is more important is
the wall thickness calculation.
To calculate how much wall thickness do
you need to keep the pressure inside
I'm guessing that a lot of people
following this broadcast are
pipe stress engnieers that are
very familiar with this formula here,
which is the wall thickness formula from
B31.3, which is pressure times
the outer diameter divided by two
times the allowable stress,
multiply the two factors there
divided by "I" see that here.
It's an "I" here and mark it in orange.
And then "I" depends on if Intrados
or the Extrados.
These are two formulas for it.
And this is just an example.
It's an extreme example because
it's easier to show by numbers.
It tested it out in several sizes as well.
But if you have a 1D bend,
this is typically the numbers
you're going to get in B31.3,
independent of the size as well.
So if you have B31.3,
you get a factor on the intrados
of 1.5, meaning that actually your
intrados needs to be thicker.
It should be thicker.
It shouldn't be the same
size as the pipe here.
If you have the same wall thickness as
the pipe and that pipe size is just by 9%
utilized, for example,
it's going to fail inside of here.
So you need to have athicker wall
on the inside and on the extrados,
which is outside here, you can
have a smaller wall thickness.
And the reason for that,
if you look at this image here,
you can see that if you do an area
calculation like we do for nozzles
in pressure vessel calculations,
and we assume that all the pressure inside
of this neutral line goes towards
and then all the pressure on the outside
of this neutral line goes to the extrados,
you can see that the areas compared
becomes bigger on this
side than this side.
And basically, this is more
explained also in the white paper
with an example, this exact example.
So when we did that simple calculation,
what is the pressure force due to this
area we got here with the pressure divide
that by the area of the extrados,
you get a factor 0.83.
So we got exactly the same as B 31.3
by hand calculation, we get 1.48
by hand, while B31.3
get 1.5, its about the same.
And then with the FEA that we can see
on the screen right now,
this number rounds up to 1.48,
which is the red area on the intrados here.
And then we got the 0.83,
which is identical to the extrados here
of B31.3 and our own hand formulas.
It gives us a value that runs
up to 0.83 as well.
So this is confirmed by FEA.
It's also confirmed by burst testing.
Basically, if I understand correctly,
sorry for jumping in.
So the idea of like you bend the pipe,
you have a thicker intrados
and a thinning on the extrados.
That isn't too surprising.
It's even part of the equations
that are in the B31.3 codes.
what I'm taking away here. That the concept
of that being a bad thing
is not necessarily so.
I mean, it's even accepted in the codes,
as I now understand exactly.
So as you say, the wall
thinning on the extrados
isn't as badly as it sounds like.
If you calculate the percentage
of reduction of wall thickness and compare
it with the allowed thinning effect,
it's not as bad as just taking the percentage
of wall thickness comparing it
to the straight pipe.
Probably going to get a few
questions about that.
So I'm going to save a little bit
more of the explanation for later.
And also the same thing is that we get
an increase in wall thickness
on the intrados,
which is also beneficial with regards
to how the stresses are
distributed in a pipe end.
this is just for the pressure calculation.
But then you want to insert your bends
into a system into a piping model.
And if you're using Caesar II,
many other softwares out there,
they all do the same with regards to the
stress intensification factors.
In this case, it's based on B31.3.
Now B31.3 has a link
to that chapter about stress investigation
factors, and it refers to B31 J.
But for the bends,
the formulas are the same.
So if you see this orange line going here,
that in plain bending stress intensification factor
based on the bending radius divided by the
outer diameter of the pipe.
So meaning that this is a one and a half D bend.
This is a standard bend. Over here
we got the 2D bend.
You can see that the stress intensification is getting lower and lower.
That's quite normal because the longer
and smoother transition you got,
the less stress concentration
you'll have in that area.
What is interesting here?
This was based on a shell study,
meaning that you have equal wall
thickness all around the FEA model.
Then we get approximately the same
numbers up to three times
the diameter and bending
radius, and then it drops down.
But what we can see, which is very nice is
that B31.3 is always giving a higher
number or the same number
as what we get from FEA.
The same goes for other plain bending.
As you can see, this line is from B31.3.
This line is from our FEA.
As long as our FEA is lower than what
B31.3 is telling us,
we're going to be on a safe side.
And then another interesting study was with
the FEA of what we call solid elements or
3D elements, where we included
the thinning and the thickening effects.
We could see that this is still the B31.3
SIF as well as this one.
So this is the in plane,
and this blue line is the in plane when we
include thinning and thickening effects.
So you can see that we are always below
B31.3, or we are equal to it.
The same goes for the outer plane.
This is the outer plane B31.3.
This is the outer plane FEA.
So as you can see it is still below,
in every case, we went up to
three and a half times the diameter
in the bending radius in this study.
So what's the conclusion here, is that as
long as you're using the SIFs from B31.3
or B31.J, you're going
to be on the safe side.
Also, with regards to the
wall thickness calculation use those
calculations and you're going
to be on the safe side.
And then this is just an example
from subsea manifold, that we did a few years back.
As you can see, there is
a lot of bends in there.
Every single bend in this
model are induction bends.
And these are six-inch pipes
schedule xxs or estra extra strong.
And the two-inch are also two inches.
same as the three inches schedule 160.
So quite significant thickness.
So it's quite significant
wall thickness on this one.
So in this case, also, you can see
that these bends here are not 90 degrees,
for example. These are bends to what suits
the system the best. And what we did here,
when you're going to code check it,
you don't need to do any hand calculations
with regards to stress intensification
factors, not with regards
to pressure containment.
If you use a B31.3, of course,
that's an important thing.
So if it's different codes
and regulations, it might be
different ways of looking at it.
But from a B31.3 perspective,
that's no problem.
Validation of what we are
doing is very important.
So this is a pipe that was
bent and bursted.
This is a six inch pipe, six inch pipe.
That is a duplex to make it easier to burst
about 14 mm of wall thickness.
Burst pressure was around 1300 bars.
So it's a safe as well.
When you start bursting these pipes, before they bent it,
all the wall thickness
was measured along the mother pipe
or the line pipe here, they bent it.
Then we could confirm the formulas
that we are using as well
as we got an accurate,
this is our 3D model.
It's not so interesting to watch because
it looks like a perfect pipe,
but it's actually not.
So we modelled
all the different wall thickness
that was measured throughout here.
Yes, a perfect representation as possible.
Nothing is perfect, but as possible.
We got the material models,
but the material properties from someone
who was testing the base material.
Also the bend material.
And we could model
that into our calculation.
it bursted over here.
As you can see in our analysis,
also indicated that it was going to burst
the plastic strain in the pipe.
And we got approximately the same range
of pressure as well where
it was supposed to burst.
And this confirmed our numerical model.
And what is interesting here is that the area
here, it was thicker than what was only extrados over here.
The extrados was thinner
than the burst area.
So you mean the plain pipe section
on the right image was thicker?
So it was thicker and it confirms also
when we talked about B31.3, chapter two,
about wall thickness calculation confirms
that as well that we can have
a thinner wall on the extrados.
And we need to have a thicker
wall on the intrados.
And this is just a cross-section
of the pipe itself where we
have made like an automized
model or a parameterized model
in SolidWorks where
if you need to do a local FEA like you do
sometimes for subsea piping,
you need to go in there,
do very local FEA,
or something called hydrogen induced stress tracking.
Then we need to see the exact
stresses at different locations.
I would like to just about to point
that out that as I mentioned,
time is always flying on these sessions.
Last time Sondre and I went on for 2 hours
straight, but we'll make
sure to avoid that this time.
We got a ton of interesting questions that really
tune into this story.
And I would love to discuss
those with both of you.
First of all, thanks
for asking the questions.
We had a question about siefs.
I feel that that is covered.
If not, Tony, feel free
to provide a follow up question.
An interesting question.
Let me just see, a question from Shazada.
Thanks Shazada, for asking.
In addition to wall thinning,
there is a loss of yield strength
of material in induction bends.
Is there some range for this
Can you maybe comment on this?
So what about material properties
and laws of yield strength?
So when we receive the modified pipe
from the Mills, we have to do test of the
pipe and see everything in the pipe.
We then have discussed with the metallurgs by the clients,
and then we try to achieve better quality
section than in the modified.
So it's very important for us to get
the modified from good deals that we can
trust the values in the test circuit.
So almost all quotes we could
give you at least the same quote.
What approach is used? Is it like all like
post-process annealing, heat treatment?
We have very often three different
certifications coming from our clients.
So that is a challenge to try to find
out what they are asking for.
And then they have to start
analyzing what they are asking for.
And we have to do a qualification test.
So when you're doing the bending,
we have to do a hardness and corrosion test
and all this after bending. And then we
have to get this approved
from the client before we start bending.
over 30 years experience
with this and we have done
over 1000 qualification tests.
We know a lot of information from different
mills, different heat numbers,
qualities and all that.
So very often we can pull out almost
the same heat number from the same mill
from before and see what
the results we get.
But very often the specification
pressures to do another qualification test
if we have it from ten times before.
I think we are one of the biggest
companies Norway doing most mechanical
testing, so we have a very good
Thanks for sharing and commenting.
I would just like to point out a comment
that Ian made, which I think
is a fairly good point.
The bend extrados should be expected
to be stronger than
the straight pipe, he writes.
Since the shape approaches a sphere,
the hoop stress in a true sphere
is half of that of a cylinder.
So that's a nice comment
in relation to the pressure tests
that were shown previously, I think. Let me just drop another question
that I saw passing by which I think is
an interesting topic for discussion, ovalization.
Shazada, thanks for asking this question,
she writes for induction bend ovality
at the welding and within
the bend can be an issue.
Please highlight this
in your discussion as well.
What is your take on ovalization?
Is there a difference in ovalization
compared to typical welded
bends in the piping system?
We have this discussion with our
clients because we never are
doing the bending in the tangent.
So very often the shape of the ends where
they are doing the welding
is light modified.
But if we have to do a
separate additional post and heat
treatment, it could maybe change
a little bit in the shape.
And then today we are doing
straightening and roding by different
metals that it could be bending
and machining it is very tight to tolerance,
but for some bigger 20-inch pipelines
very often are doing
hard forming of the ends
to be within the tolerance.
When we are not doing any post
bending heat treatment
We are not going to do any process
to the end, but still we have to try
to serve the customer with
the end preparation,
and we're doing the bevelling.
And in the same time we're
doing the bevelling.
We are very often doing the machining
to the inside and outside.
But this is quite a very critical
operation to reach the tight tolerance.
Specially if you're doing a glass pipe and you
have maybe a three millimeter
pipe and a little bit ovality at the end then you
don't have the machine to make sure.
So that's always a challenge,
but it's a very good question and we have
to have focus on it from the beginning.
Thanks for detailing that.
Another question from Ian,
which maybe Sondre you can share your
thoughts about this, do you make any
distinction or did you make any
distinction in the analysis that you
did between seam-welded and seamless
I now understand this
question a little bit better.
So if you do like induction bending,
do you make a distinction between
seam-welded and seamless base pipe?
What is your comment?
I'm just thinking here. Seam welded, do you
have anything to add on the
fabrication method there?
Do you see any how
do you make it?
So when we receive
the RFQ and we make a quotation,
we make all the induction bending