Tube Products International March 2015

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March 2015 Tube Products International 39
products & developments
Protecting carbon steel press-fittings
systems from corrosion
Carbon steel press-fitting systems
are more susceptible to corrosion
than stainless steel. From storing to
commissioning, it is best practice to
protect carbon steel pipes.
One of the characteristics of press-
fitting systems is the use of pipes with
reduced thickness. Compared to piping
of the same material but thicker, this
offers advantages such as greater
manageability, lower system weight,
greater capacity compared to pipes
with the same external diameter, lower
transport costs, and less environmental
impact in both the production and
moving phases.
However, the reduced thickness makes
carbon steel pipes more susceptible
to corrosion. As Eurotubi fittings and
pipes are treated with galvanising
processes to protect them from
corrosion, installation and testing must
be performed according to the Eurotubi
Pressfitting Technical Manual.
Transport andstoragemustbeperformed
properly to prevent water infiltration,
the formation of condensation and the
presence of dirt. Pipes must remain
capped until just before installation.
When the products cannot be stored in
areas with controlled temperatures and
humidity, the fittings and pipes must
be inspected periodically. Accidental
impact of the pipes and fittings should
be avoided, paying particular attention
to sharp surfaces, especially if made of
other ferrous metal materials.
Carbon steel pipes for heating
systems must be protected from
external corrosive agents, such as
humidity, using insulation. Precautions
are taken with buried pipes where
external corrosion becomes particularly
aggressive. Effective insulation methods
include coating with closed cell sheaths;
painting; and coating with protective
tape (leaving no parts uncovered). Felt
banding should not be used, as it retains
moisture for a long time, promoting
corrosion.
The final testing phase for a carbon
steel system is fundamentally important.
Air and stagnant water must not be
allowed to remain in the system for too
long before it is completely refilled. If the
system is not to be used immediately, it
is best to perform the testing procedure
using air or inert gas, being careful
to slightly dampen the O-rings before
assembly.
Carbon steel systems must maintain
the closed circuit condition without
any air inside. During the refilling and
maintenance phases, a small amount
of air could penetrate the circuit. In this
case, it must be discharged through
the venting valves. Special additives
may also be used to neutralise oxygen,
inhibiting corrosion.
If the system must be emptied and
shut down for a certain period of time,
Eurotubi recommends passing dried air
through the pipes in order to dry them
completely.
Eurotubi Europa Srl – Italy
Stainless steel experience
Tecnica Tre, founded in 1996, is a stockist
of stainless steel flanges, fittings and
pipes. The company’s warehouse holds
3,000m2 of stock, semi-automatically
managed with WMS and barcodes,
with room for 5,000 pallets, and with
automatic management of batch
numbers and packing lists.
The dimensional control process and
chemical analyses on materials ensure
quality. The range of products includes
EN and ASME flanges, EN and ASME
butt welding fittings, threaded fittings,
fittings and unions for the food and
wine industry, and ASME welded and
seamless pipes.
The company supplies a range of different
sectors, and deals with companies of all
sizes. Managing director Mr Scotton
commented, “The success of our
business is due to two factors: good
price/quality ratio and excellent service.
The ample supply and assortment in our
warehouse enable us to promptly satisfy
requests in a market that is evolving
rapidly. We are always searching for new
items to add to our stock in order to meet
the demands of our valued customers.”
Tecnica Tre recently launched a new
website that offers customers the ability
to make quotations and orders, while
constantly checking the stock and price
levels. All purchase orders received are
reviewed by sales staff prior to being
released to the warehouses.
Tecnica Tre Srl – Italy