In highly sensitive industrial environments such as petrochemical plants, nuclear power stations, and pharmaceutical processing units, valve integrity and emission control are critical. External Stem Bellow Seal Globe and Gate Valves are engineered specifically to meet these demands, offering absolute sealing performance, zero stem leakage, and long operational life.
Designed with a flexible metallic bellow that hermetically seals the stem movement, these valves prevent fugitive emissions and ensure the highest level of safety, even in highly toxic or hazardous media applications.
Understanding the DesignThe hallmark of bellow seal valves is the multi-ply metallic bellow welded to the valve bonnet and stem, forming a leak-proof seal. In external stem designs, the rising stem moves outside the bellow chamber, allowing for easy visual position indication and reduced wear on internal parts.
Both globe and gate configurations are offered in this design:
Globe Valve: Ideal for throttling and regulation
Gate Valve: Preferred for full shut-off with minimal pressure drop
Key Features and Benefits
Zero Emission Technology: Ideal for meeting EPA and TA-Luft standards
Extended Service Life: No packing failure or stem leakage
Fire-Safe Design: Secondary sealing in case of bellow rupture
Corrosion Resistance: Available in stainless steel, Hastelloy, and other alloys
Ease of Maintenance: External stem and bolted bonnet simplify servicing
Accurate Positioning: Rising stem allows clear valve status visibility
Applications Across Industries
Petrochemical Plants: For handling hydrocarbons, benzene, and VOCs
Refineries: Used in hydrogen service, catalytic reforming, and steam lines
Pharmaceutical Industry: For sterile and contamination-free systems
Power Generation: Including nuclear and thermal plants, for steam isolation
Cryogenic Service: Special bellows available for liquid nitrogen and oxygen
Compliance and Safety Standards
Designed and tested as per API 602, BS 1873, DIN EN ISO 15848-1
TA-Luft, Fugitive Emission Certified
Fire-Safe per API 607 / ISO 10497
Advantages Over Conventional Valves
Eliminates need for gland packing
Prevents hazardous media from escaping
Reduces environmental contamination risks
Ensures plant personnel safety
Long cycle life even in corrosive or high-temperature media
ConclusionFor industries demanding absolute safety, low emissions, and reliable performance, External Stem Bellow Seal Globe and Gate Valves provide a trusted solution. Their ability to isolate hazardous media and prevent leakages makes them indispensable in high-risk environments.
Freture Techno Pvt. Ltd., a trusted name in precision-engineered flow control systems, offers a wide range of bellow seal globe and gate valves built to global standards. With expertise in metallurgy, custom design, and quality assurance, Freture delivers durable valve solutions for the most challenging operating conditions.
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