Bellows Accumulators

Metal bellows accumulators are used in a variety of industries to store the energy of a liquid or gas. Edge welded bellows technology is an ideal fit for this application, due to its media compatibility and stroke length capability. Edge welded bellows can also be manufactured in a variety of materials to match the application’s media compatibility requirements. With the right material, metal bellows can operate from cryogenic temperatures to 1500°F.

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. 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 accumulator.

Metal Bellows Accumulator with Housing

BellowsTech has engineering design experience in a multitude of applications resulting in manufacturing a variety of accumulator sizes and shapes. With over eighty standard diaphragms to choose from, engineers have the ability to select the right size for the application. BellowsTech is also capable of manufacturing bellows up to 96” in length.

Guides and over-travel stops can be integrated into the design. In order to prevent “squirm,” guides ensure that the bellows assembly is moving in the intended direction. Over-travel stops can prevent bellows expansion from over-pressure conditions.  Special housings can be designed to contain pressure as well as allow input and output pressure ports to customer design needs.

Specifications (Bellows Accumulators – PDF)

Common MaterialsAM350, 316L SS, Inconel®, Titanium, & Hastelloy® 276C
Thickness0.002″ and up every 0.001″
Standard Leak Rate<1×10-9 std CC He/sec**
Size Ranges 
Outside Diameter0.358″ (9.0932mm) to 22.205″ (564mm)*
Inside Diameter0.198″ (5.029mm) to 19.921″ (505.99mm)*
ShapesRound standard. Non-Round Available; Contact Factory.
LengthUp to 96 inches (244 cm)

*For other dimensional requirements, contact the factory
**Confirm leak rate with material selected.


There are over 90 Standard Diaphragm sizes available.

View the entire die list here and quickly choose the best fitting bellows mechanical seal for your application