A world made of metal


Metal Bellows for Industrial Applications

When you think of the word "bellows" you
probably have a picture in your mind of theThese processes are mechanical forming, and
leather bellow historically used to blow airhydroforming. Formed bellows are generally
into their fireplace. However, there ismore expensive for a custom bellows than if
another kind of bellow, a metal bellows,it were welded. The higher cost is due to the
which is a high-technology product used intooling required to produce the original
machinery, medical and industrialform. However, once the original form has
applications. Metal bellows are manufacturedbeen created then the subsequent bellow can
and sold by companies specializing in metalbe produced at a lower cost than individually
expansion joints and other piping systems.welded  bellow.
Some bellows are microscopically small while
others  are  very  large.Formed bellow must be made of metals which
have high elongation characteristics. For
Simply stated, metal bellows are thin-walledthis reason, most formed bellow are made of
flexible elements which allow for expansionbrass. Formed bellows generally are used in
in a system of pipes, while at the same timeapplications where a lower performance is
containing gasses and liquids in aacceptable. Formed metal bellows are also
pressure-filled environment. A metal bellowgenerally larger than those which are
is also commonly referred to by the names:individually  welded.
flexible metal element, element,
corrugations,  and  compensator.Welded Bellows - A welded metal bellows is
manufactured by welding individual formed
Each metal bellow is made by taking intodiaphragms to each other. A welded bellows
account its pitch, convolution height,can be fabricated in many shapes and sizes
thickness, number of plies, convolutedand is generally a higher performance option
length, skirt length, and inside diameter.than  a  formed  bellows.
Every metal bellows has a unique working
pressure, life cycle, and spring rate whichWelded bellow can be made of any metal or
are entirely dependent on their shape and thealloy which can be welded. Generally,
material in which they are made of. Thesematerials such as stainless steel, titanium,
considerations, and some specificand other non-corrosive materials are used to
mathematical formulas, insure that a metalfabricate  welded  bellows.
bellow meets the standards set by the
Expansion Joint Manufacturers Association.Formed metal bellow generally are used in
The EJMA specifications exist to make surelarger applications such as HVAC, and large
that a metal bellow is able to perform underpiping systems. Welded bellows are generally
the specifications it claims to. This is forvery small and have to be manufactured in
both  productivity  and  safety.laboratories using high levels of
magnification. Welded bellows are generally
There are generally two different types ofused  in  medical and aerospace applications.
metal bellow available on the market today.
These two types of bellows are formed andAs you can see there are many metal bellows
welded.  Let's  look  a  bit at each of them:available to fit many needs. Bellows are
available from companies who fabricate metal
Formed Bellows - A formed metal bellows isexpansion joints.
manufactured  by  one  of  two  processes.



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