Cast Steel Gate & Globe Valves
In a bellows seal globe valve, the stem is fully isolated from the process fluid by a metal bellows welded to the disc at one end and to the bonnet at the other. This removes the packing leak path; the packing remains only as a secondary seal.
Overview
On thermal oil lines a leak means both a fire risk and oil-soaked insulation; with toxic, flammable and expensive chemicals it is an occupational safety and fugitive emissions issue. Bellows life is designed around the number of strokes and the pressure and temperature conditions; multi-ply bellows give a longer cycle life.
Technical specifications
| Design | Multi-ply stainless steel bellows; backup packing |
|---|---|
| End connections | Flanged (EN 1092-1 or ASME B16.5), butt-weld, socket-weld |
| Materials | Carbon steel, stainless steel or Cr-Mo body; bellows 316Ti / 321 or similar |
| Applications | Thermal oil, toxic and flammable chemicals, vacuum, zero-emission targets |
Key features
- Zero stem leakage
- Packing as a secondary seal
- Long cycle life with multi-ply bellows
- Anti-rotation stem lock
Documentation and testing
On industrial projects the documentation package matters as much as the valve. We confirm the certificate and test scope for every line item at quotation stage:
- EN 10204 3.1 material certificates for pressure-retaining and wetted parts, traceable by heat number
- EN 10204 3.2 with third-party inspection, on request
- Pressure test reports to API 598 or EN 12266-1: shell, seat and, where specified, gas tests
- Fire-test certificates (API 607 / ISO 10497) for fire-safe type-tested designs
- PMI reports for alloy and stainless materials
- Dimensional, visual and coating inspection records
- PED 2014/68/EU CE declaration for equipment within its scope
- NACE MR0175 / ISO 15156 compliance statement for sour (H₂S) service
Technical datasheet
Frequently Asked Questions
What happens if the bellows fails?
The packing acts as the secondary seal and limits leakage. Because bellows life is designed around the number of strokes and operating conditions, the required cycle life should be defined at the selection stage for frequently operated valves.
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View detailsRequest a quote: Bellows Seal Globe Valve
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