For structures and equipment operating in harsh
environments, springs and spring fasteners must be able to
withstand different types of extreme conditions including
underwater, outdoors and very high or low temperatures, as
global spring company Lee Spring explains

Challenging working conditions can
be encountered across various
industry sectors, such as aerospace,
valve manufacturing, offshore and sub-sea
industries, medical, power station and
nuclear industry, turbine manufacture and
general engineering. Springs and fasteners
are often vital components of various
equipment and therefore must be designed
to withstand the application-specific
conditions.

“Working in a harsh environment could
mean anything from equipment required
underwater, battling saltwater corrosion or
contact with ‘sour’ gas from drilling down
under the sea bed, to 35,000 feet up in the air
contending with high wind speeds and low
temperatures”, says Nick Lungley,
applications engineer at Lee Spring. “An
offshore application requires equipment that
can brave the elements, and some
manufacturing or furnace applications
involve extreme heat or cold, while some will
require equipment to be subject to highly
corrosive substances.”
Custom engineering in spring design can
help to ensure that the spring or fastener has
been manufactured to suit the specific
requirement, choosing from a wide variety of
advanced spring materials.

Alloys (metals made up of more than one
type of metal) are often used as they offer a
higher resistance to corrosion. Lee Spring,
offers high performance nickel and cobalt
‘superalloys’, which provide good mechanical
strength as well as resistance to corrosion,
oxidation and deforming at high
temperatures or under extreme pressure.

Equipment used in sub-sea or offshore
applications is subject to the risk of corrosion
from various elements including salt water,
wind and rain, so springs required for these
applications can be made using corrosion
resistant nickel based and cobalt alloys,
including MP35N, Monel, Inconel, Nimonic,
Hastelloy and Elgiloy.

The nickel-cobalt alloy MP35N, which
consists of nickel and cobalt, is resistant to
hydrogen sulphide, salt water and mineral
acids, so is well suited to marine and sub-sea
applications where salt water can have a
highly corrosive effect on most metals. The
nickel based alloy Monel incorporates
copper and iron and is corrosion resistant,
as well as acid resistant, so is suitable for
marine applications as well as applications
involving acids and highly corrosive
substances.

“The selection of the correct material for a
specific, demanding application is critical”,
says Darren Eyre, technical specialist at Lee
Spring. “For instance, stainless steel is a
tough and corrosion resistant alloy, but does
not offer the properties required to
withstand extreme heat and is likely to
distort at a high temperature. It is therefore
important to clearly understand the
environment it is likely to be used in.”
Inconel alloys, which are available in
different grades (600, X-750 and 718), are
suitable for valves, pumps or actuators, or
applications involving high pressure and
high temperatures, such as in nuclear power
stations or drilling on offshore platforms.

Also corrosion resistant and suitable for high
temperature and high pressure applications
are Nimonic and Hastelloy alloys.

Lee Spring offers custom engineering in
spring design and a range of materials,
available up to 19mm diameter, alloys and
nickel and cobalt superalloys including
Inconel, Nimonic, Hastelloy, Monel, Elgiloy
and MP35N. Other alloys available include
stainless steel, phosphor bronze and
beryllium copper.