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Bellows valve

What is a Bellows Valve?

A bellows valve is a valve that uses a metal bellows instead of traditional packing gland at the stem seal. The bellows completely isolates the stem from the valve cavity, achieving zero external leakage. This makes it ideal for handling toxic, flammable, precious, and environmentally sensitive media.

Bellows valves are widely used in chemical, petrochemical, nuclear, pharmaceutical, and semiconductor industries where ANY leakage is unacceptable.

Working Principle

The bellows is a flexible, multilayer metal element. One end is welded to the stem, the other end to the bonnet. When the stem moves up/down, the bellows expands/compresses while maintaining a hermetic seal. Even if the bellows ruptures, the packing provides secondary sealing (double seal design).

Bellows Material Comparison

SS304 Bellows

  • Temp: -196°C ~ +400°C
  • Corrosion: General
  • Cost: Economical
  • For general media

SS316L Bellows

  • Temp: -196°C ~ +400°C
  • Corrosion: Good
  • Cost: Medium
  • For corrosive media

Inconel 625 Bellows

  • Temp: -196°C ~ +650°C
  • Corrosion: Excellent
  • Cost: High
  • For extreme conditions
Bellow Sealed Gate Valve

Bellow Sealed Gate Valve

Bellows Sealed Globe Valve

Bellows Sealed Globe Valve

Bellows Sealed Globe Valve

Bellows Sealed Globe Valve

Bellows Sealed Globe Valve

Bellows Sealed Globe Valve

Bellows Sealed Globe Valve

Bellows Sealed Globe Valve

API Standard Bellow Sealed Globe Valve

API Standard Bellow Sealed Globe Valve

Extend Stem Globe Valve

Extend Stem Globe Valve

Technical Specifications

ParameterRange
Size RangeDN15 - DN400 (1/2" - 16")
Pressure Class150LB - 1500LB (PN10 - PN260)
Temperature Range-196°C to +650°C
Body MaterialsWCB, CF8, CF8M, WC6, WC9
Bellows MaterialsSS304, SS316L, Inconel 625, Hastelloy
Bellows Life≥10,000 cycles
End ConnectionsFlanged (RF/RTJ), Butt Weld, Threaded
Design StandardsAPI 602, GB/T 12235, DIN 3356
Leakage ClassZero external leakage (ISO 15848-1 BH)

Industry Applications

  • Chemical: Chlorine, phosgene, benzene — Bellows globe valve
  • Petrochemical: FCCU, hydrotreating — Bellows gate valve
  • Nuclear: Radioactive media handling — Bellows gate/globe valve
  • Pharmaceutical: High purity, sterile media — Bellows diaphragm valve
  • Semiconductor: Ultra-high purity gases — Bellows valve
  • Vacuum: Vacuum system isolation — Vacuum bellows valve

Need Zero Leakage Valve Solutions?

Our bellows seal valves provide absolute stem sealing for toxic, flammable, and environmentally sensitive media. API 602 certified, ISO 15848-1 BH class.

Email: info@chlgvalve.com Call: +86-15601794339