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running and then managing the this interesting work! But nobody in the
running time of the facility. The initial surrounding society noticed we were
idea we envisaged had to be scaled up even doing it. By that measure, it’s been
to give us more control and allow more a success, but the testing itself has been
testing to be done at the same time. So a success as well. We have been able to
that was the whole exercise – a really do over two years of testing, in a range
big exercise. of conditions that allowed us to simulate
over one hundred years of lifetime for
DM: One study carried out by Northern a real installation. It has given us a lot
Gas Networks took Leeds as an example of confidence about the way a real pipe
and built a model to show how we system – not just the material – will
could convert Leeds to hydrogen, behave.
using this as a basis for changing the We looked at things like the strength
UK. Technically, at that time, the gas of a pipeline, we looked to make sure
distribution system would have been that it’s going to be strong enough for
converted from metal pipes at the the next hundreds of years – that will be
end of the 30-year programme during a big engineering safety factor. We want
which we have been converting to a to ensure there’s no possibility of the
fully welded plastic system with a long pipe or the fitting system rupturing in
predictable life and reliability. So, we an unplanned or uncontrolled manner.
had all the grounds to think we could We want to know it’s just going to sit
put hydrogen into that instead. What there and behave itself.
the regulator wanted was an evidential One thing you need to understand
approach to say: we believe it’s right, with polyethylene pipes is that gases
and we can prove it. At the time we can permeate through the wall of
choose to do it, our network will be polymer structures, so you will get
mostly made of polyethylene pipe, so some molecules of hydrogen going
we would like to have the evidence to through. It’s not rushing through;
prove that if we put hydrogen into it, a molecule might pop through every
it will be reliable, it will be safe and once in a while, but hydrogen sits
ideally it will last for a hundred years there. Does it change the nature of the
or more into the future without any materials to that point that if you impact
significant risk to society. it, it might drive a fracture into the
When we started our investigation, pipe? So, we’ve explored that too.
the first thing we had to think about What can happen in a pressurised
was what aspects of the lifecycle of pipeline is, if you drive a fracture and
a polyethylene pipe are affected by the pipes are at certain temperature, a
INSIDE THE TESTING FACILITY hydrogen. That required us to look at certain material with a pressurised gas
the design of a series of experiments, can create a phenomenon known as
during which we could collect evidence. rapid crack propagation (RCP). This is
People believed that hydrogen can something that we understand as a failing
supplying the gas networks; then you be used with polyethylene and work mode; it’s something that we test for and
have the suppliers of PE pipe, which is has been carried out in that area over when you see the test, it’s dramatic. You
our side; and you have those that will be the last 50 years, but it has been done know, a pipeline can literally unzip
making the boilers, heaters and cookers with a ‘block of material’ and that within a fraction of a second, and when
that would run on hydrogen. There doesn’t tell you how a pipe will behave. I say ‘unzip’ I’m talking about hundreds
were offers of sponsorships and grants So, as Simeon mentioned, we worked of meters, in a rapidly driven crack
to carry out research and our bid to do with lots of oversight from the Health & through the network.
just that was accepted, but we needed Safety Executive, from subject experts That’s a phenomenon that’s never
to find a testing facility and there were like Kiwa, and from the emergency happened in real networks, because we
none capable of carrying out hydrogen services, for example the fire brigade understand the conditions for it and place
testing in the UK. and other specialist consultants, to a big safety factor on it. What we have to
I had prior experience with hydrogen ensure we developed a safe and reliable understand is, if we change the gas, does
and when I saw how things were I system. Certainly everybody who that become more or less likely?
thought, “Okay, we need help from works in our business noticed that the The one thing I can tell you for
people with more safety experience facility was running and doing all of hydrogen – and this was one of the
than myself,” so that’s how we ended interesting findings – the failure mode
up contacting various hydrogen We looked at things like the of RCP, which I will say again, we
consultants to come in and help us don’t have, because we’ve designed
bring things together. Once the facility strength of a pipeline, we it out – is actually even less likely to
was up and running, I was the one looked to make sure that it’s happen with hydrogen. The nature of
mainly taking care of operations going to be strong enough for hydrogen means it just can’t create the
like collecting data and making sure the next hundreds of years – energy at the crack tip to drive those
everything was maintained, putting kinds of cracks, so actually, going from
in new tests, etc. The challenges were that will be a big engineering methane to hydrogen is a safer choice
twofold: getting the facility up and safety factor in that sense. That was an interesting

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RadiusHydrogen.indd 2 11/02/2021 13:35