What is a bellows sealed globe valve?
A bellows sealed globe valve is a linear shut-off valve where a multi-layer metal bellows surrounds the stem and is welded to body and stem. This metallic bellows forms a continuous, leak-free barrier to atmosphere. In a conventional packing seal the packing sits directly on the moving stem and wears in service. In a bellows valve the bellows itself moves — wear on the sealing surface is eliminated. The design follows EN 13709 for industrial globe valves.
TA-Luft globe valve — tightness Class A to ISO 15848-1
A TA-Luft globe valve must meet the German Clean Air Act requirements for stem sealing. Since 2015, tightness Class A per EN ISO 15848-1 is aligned with the TA-Luft criterion — Class A meets TA-Luft. All Fergo bellows globe valves are tested and certified to this standard. For plants subject to fugitive emission regulations, a bellows valve is the safest choice. All certificates and approvals are available in the shop.
Bellows globe valve — technical data
- Nominal size: DN15 to DN300
- Pressure rating: PN16 to PN40, ASME Class 150/300/600
- Body: stainless steel 1.4408 (CF8M), carbon steel 1.0619 (GP240GH/WCB), cast iron EN-GJL-250
- Bellows: X6CrNiMoTi17-12-2 (1.4571), AISI 321, SS304 — multi-layer, welded
- Plug: stainless steel 1.4021 (X20Cr13 + QT), optional stellite-hardened
- Seat: stainless steel, optional hardened
- Packing: graphite (safety packing as second seal)
- Flange: EN 1092-1/-2, ASME B16.5
- Face-to-face: EN 558-1 Series 1
- Tightness: Class A per EN 12266-1
- Temperature: up to +300 °C (cast iron PN16), up to +450 °C (steel PN40)
- Certificates: TA-Luft per ISO 15848-1, AD2000
- Conformity:EU Pressure Equipment Directive 2014/68/EU
Bellows valve vs. packed globe valve — why a bellows?
| Feature | Bellows globe valve | Packed globe valve |
|---|---|---|
| Stem seal | welded metal bellows + safety packing | packing (PTFE or graphite) |
| External leakage | near zero (Class A) | possible on wear |
| TA-Luft compliance | yes (ISO 15848-1 Class A) | special packing only |
| Stem seal maintenance | maintenance-free (bellows life) | regular tightening/replacement |
| Typical media | steam, thermal oil, chemicals, toxic gases | water, air, standard media |
| CAPEX | higher | lower |
| OPEX (LCC) | lower (less maintenance, no leakage cost) | higher (retightening, media loss) |
For standard media such as water and air a conventional flanged globe valve is sufficient. For steam, thermal oil, chemicals and wherever TA-Luft compliance is required, a bellows sealed globe valve is the technically and economically better choice.
Applications — steam, chemicals, pharma and power plants
A bellows globe valve suits any application where fugitive emissions must be eliminated. In steam and hot water systems the bellows valve prevents steam losses and secures the line ahead of steam traps and heat exchangers. In thermal oil systems the metal bellows prevents leakage of hot heat-transfer fluid. In chemical and pharmaceutical processes a TA-Luft globe valve isolates toxic or flammable media reliably from atmosphere. In power plants and refineries the bellows valve meets fugitive emission requirements. Check material compatibility with our resistance check tool.
Bellows globe valve in stock — EU-wide delivery
Fergo stocks all 128 bellows globe valve variants for immediate dispatch. Filter by size, pressure, body and certificate through the configurator above. Standard shipping via DHL reaches customers across Europe within a few working days. Each bellows valve ships with works certificate, datasheet and declaration of conformity. For automated processes Fergo supplies the valve with pneumatic or electric actuators — including actuator sizing and assembly. The matching flange gasket is supplied alongside.
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