• Edge Welded Bellows
  • Servometer Edge Welded Bellows

Edge Welded Bellows

ABSSAC supplies dependable edge-welded bellows and assemblies. Engineers in a broad spectrum of industries rely on bellow products for the highest cycle life, responsive design, wide material selection, and leak-tight performance. Metal bellows provide an all-metal pressure barrier and seal that flexes in one or more directions. Edge welded metal bellows provide the most flex in the smallest amount of space of any bellows technology on the market.


The finished product is a long flexible assembly. The design of the metal diaphragms gives the bellows assembly its dynamic flexibility and high – performance characteristics. Most customers require end plates or custom flanges to meet a specific requirement or application and these end pieces can be welded to the end of each side of the bellows for a finished assembly.

If you have an application where the control of volume in a liquid or gas is important, the edge welded bellows product may be able to help. Providing the most flex in the smallest amount of space, we are dedicated to developing and perfecting edge welded bellows design, fabrication and manufacturing technologies with full application design assistance. Using state-of-the-art manufacturing capabilities allows our customers to  benefit  from exact requirements.  We excel at optimising the design and attachments so that we have consistently achieved outstanding performance and reliability reviews.  For applications that require high quality micro fusion joining, edge welded bellows are more cost effective and functional than either electron beam or laser welding. We can design and manufacture edge welded bellows in a full range of diameters and thicknesses.  In order to address custom requirements, our design specialists will review each application which allows us to determine the exact custom capabilities needed to ensure your success.

With various materials and configurations, the bellows product can achieve the pressure, temperature, and leak rate requirements that customers demand. Edge welded bellows can be used as actuators to convert pressure and/or temperature into motion or volume compensators that can balance pressure and or temperature differentials to ensure continuous, accurate operation of a system. Other applications have included accumulators, feedthroughs, vibration dampeners and face seals. There are over 90 standard diaphragm sizes available, however bespoke design are also welcomed.

  • Edge Welded Bellows

Working with materials such as AM350, Stainless steel, Titanium, Hasteloy, and Inconel, we will design and manufacture bellows to your exact requirements ( See table below) .  In fact we can weld any weldable alloy that is commercially available. In the past, the product has also been used as a liquid or gas accumulator, expansion joint or actuator.

Minimum outside diameter 9.0932 mm (0.358inch)
Maximum outside diameter673.1 mm (26.5 inch)
Minimum material thickness0.05mm (0.002inch)
Maximum material thickness 0.91mm (0.036inch)


Hydraulically formed, or hydroformed, bellows can typically travel about twenty percent of their free length. Edge welded metal bellows have the ability to travel ninety percent; thus, edge welded bellows can accomplish the same movement in smaller sizes and lighter weight assemblies. Bellows accumulators can have pressure internal or external to the bellows assembly. This design factor should be defined early in the design phase since the assembly will ideally receive internal pressure. Understanding the differential pressure between the inside and outside of the assembly also helps engineers to determine the proper size and length of the bellows assembly.

Offering proprietary stamping, cleaning and welding techniques for exceptional strength and consistency in the product. Pride in the product is demonstrated by individually inspecting diaphragms for the highest quality to ensure welds are the strongest and leak-tight and then employing special handling techniques to protect against contamination of the materials.

Other product advantages include;

  • Deep penetrations and consistent weld bead geometry to ensure a leak-tight joint
  • Can withstand high cycle applications
  • Engineered for optimal performance with an internal vacuum or external pressure
  • Optional heat treating to strengthen the material
  • Helium leak testing to industry standards (1×10-9 for stainless steel material)
  • Lower leak rates are available as required
  • Over 90 standard sizes, round and non-round shapes
  • ISO 9001:2008 certified, AS9100 compliant
  • Quality Assurance Certificate

Industries to date that have benefited from this technology include;

  • Vacuum Industry
  • Semiconductor
  • Aerospace
  • Medical
  • Defence
  • Oil and Offshore
  • Solar Energy
  • Cryogenics

Why not give us a call to discuss your edge welded bellows requirement or just fill in the application data form.

Material Selection Guideline








Industrial, High Vacuum and other liquids and gases with low corrosive properties

-100 to
800° F

Highest strength/cycle life with low leak rate

300 Series SS


Industrial, High Vacuum and other liquids and gases with mild corrosive properties

-420 to
800° F

Lowest cost materials with low leak rate



High temperature and corrosive applications such as exhaust, seawater, hydrogen sulfide,and heavy oil

-420 to
1500° F

Good corrosion resistance, yet limited leak rate

276 C


Highly corrosive media such as petrochemical processing equipment

-420 to
1500° F

(Haynes 242 up to 1300° F)

Excellent compatibility; high price point

Titanium Grades
1 through 4



Light-weight aerospace and invasive medical equipment

-420 to
800° F

Extremely light-weight and capable of being implanted; highest price performance ratio

Edge Welded bellows offer a wide variety of materials with a range of media compatibilities. Contact Us or call 01386 421 005 for additional information.

Standard Diaphragm Sizes for Edge Welded Bellows