Today's Industrial Products and Solutions May 2019 | Page 22

There may not even be a weld procedure in exis-
tence for the client’s specifications. It then is up
to the fabricator to define and achieve the weld
parameters that have never before been made.
Says Covan, “we’ve had to literally write the man-
ual through the process of fabricating the vessel.
We will work with metallurgists on the client side
who require certain things without the benefit
of any real precedent in the market because the
weld has never been made before.”
a piece of equipment that meets their unique and
challenging specifications.
Staying in Code
Metallurgical craftsmanship is also called upon
As in the case of Tate & Lyle’s plant, complexi- in the repair of corroded vessels. According to
ty can start with the original design request. A Covan, “a lot of highly corrosive chemical catalysts
process engineer will draw up a concept and then move in and out of exchangers. We can apply
turn to a company like Mitternight to determine overlays of weld metal with a process that build
how to create it. According to Lance Covan, owner up the thickness lost to corrosion given the caus-
of Mitternight, “Our clients will look to us for the tic environment. It’s one thing to do this with car-
code specifications, identify what’s allowable, de- bon steel, but when you deal with specialty noble
fine what will meet the certifications of the given metals, this kind of work is highly specialized.”
parameters they have in their plan and also what
will not.”
Industrial quality control specialists like Tate &
Lyle’s Linda Rutherford regularly monitor the
The design of a new complex processing vessel thickness of vessels to ensure they remain in
is a product of material selection which itself is specification. “A key to durability is selecting the
based on temperature and pressure consider- right metals in the first place”, says Rutherford.
ations. A fabricating specialist will identify all the “Then when repairs and maintenance are needed,
parameters based on ASME, metallurgical and the code work needs to be completed and recerti-
temperature requirements to meet a client’s pro- fied. We’ve asked Mitternight to repair and com-
cess needs. plete replacements of pressure vessels and heat
exchangers.”
Once a vessel is designed and engineered, fab-
ricating to meet the performance specifications Vertical Integration Supports Long-Term Success
requires expertise and craftsmanship in metallur- With so much invested in the performance, safety
gy. And specialized alloys selected for their per- and durability of complex process vessels, op-
formance attributes can themselves be inherently erators can find a lot of value in working with
challenging. Welding specialized high-grade nickel a fabricator who not only has expertise in spe-
alloys of up to 99% nickel, such as Nickel 200 for cialized metal alloys but who can partner with
example, is a demanding process. them through the entire design-engineer-fabri-
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TIPS Magazine • May 2019