Welded Diaphragm Metal Bellows

Welded Diaphragm Metal Bellows

Welded Diaphragm Metal Bellows

Welded Diaphragm Metal Bellows Description

Welded Diaphragm Metal Bellows are composed of two contoured diaphragms – each constructed from thin stainless steel – are welded at the inside diameter to form a convolution. Capsules are formed when convolutions are stacked on a horizontal arbor and welded at the outside diameter. Most welded diaphragm metal bellows have a nested ripple diaphragm configuration that provides maximum stroke, minimum stress, superior flexibility, and full nesting when collapsed or compressed. Customized bellows, including those with flat plate, single sweep, and torus contours, are available for special applications.

Type 374 stainless steel ensures corrosion resistance, weld-ability, and engineering properties that perform in temperature ranges from cryogenic to 800ºF and beyond. Type 347 stainless steel is ideal for high-vacuum applications, research, instrumentation, and volume compensators – wherever moderate pressure, maximum stroke and constant spring rates are required. Other commonly used materials include AM 350 stainless steel, Inconel, titanium and hastelloy.

Depending on applications, the service life ranges anywhere between 5,000 cycles to infinity. Reduced stroke and additional capsules increase bellows life.


  • Wide range of operating temperatures
  • Constant effective area with change in pressure
  • Excellent spring and pressure deflection characteristics
  • Ability to withstand high pressure
  • Long stroke per unit length
  • Short nestled length
  • Corrosion resistance
  • Leak tightness to less than 1X10-10scc/sec


OTS welded bellows are ideal for moderate pressure and high vacuum applications where immediate availability is critical. Such applications include:

  • High vacuum seals
  • Leak-free motion feed throughs
  • Flexible joints
  • Volume compensators, accumulators
  • Pressure and temperature actuators


  • Defense
  • Oil and Gas
  • Semiconductor
  • Medical
  • Industrial


Product Resource Links:

OTS Bellows Brochure

OTS Pumps-Compressors

Metal Bellows Design Sheet

Metal Bellows Pump Compressor Design Data Sheet