Forbes Marshall Bellows Seal Stop Valve (Globe Valve)
Forbes Marshall Bellows Seal Stop Valve (Globe Valve): SEO Guide & Technical Specifications
Forbes Marshall Bellows Seal Stop Valves are zero-emission, maintenance-free industrial globe valves designed for critical throttling and positive shut-off duties in steam, thermal fluid, and hazardous gas pipelines. Featuring a multi-ply stainless steel bellows seal arrangement, these valves eliminate gland packing leaks, ensuring operator safety and preventing energy loss in high-pressure steam distribution systems.
Key Technical Specifications & Standards
|
Parameter |
Technical Specification |
|
Valve Type |
Bellows Sealed Globe / Stop Valve (Outside Screw & Yoke) |
|
Design Standards |
EN 13709 / BS 5160 / DIN 3356 |
|
Size Range |
DN 15 mm to DN 300 mm (1/2" to 12" ) |
|
Pressure Ratings |
PN 16, PN 25, PN 40, ANSI Class 150, ANSI Class 300 |
|
Body & Bonnet Material |
Cast Iron (EN-JL1040), Cast Steel (ASTM A216 Gr WCB / EN 1.0619), Forged Steel (ASTM A105) |
|
Bellows Material |
Multi-ply Stainless Steel AISI 316L / AISI 321 |
|
Plug & Seat Trim |
Stellite Faced / Hardened Stainless Steel (SS 410 / SS 316) |
|
End Connections |
Flanged (EN 1092-1 / ANSI B16.5), Butt-Weld, Socket-Weld |
Core Engineering Advantages & Features
- Zero fugitive emissions: Multi-ply stainless steel bellows forms a hermetic seal around the stem, completely isolating fluid media from the atmosphere.
- Secondary Safety Packing: Outfitted with an auxiliary graphite gland packing box to provide secondary backup sealing in emergency conditions.
- Non-Rising Handwheel with Position Indicator: Facilitates smooth operation in tight spaces while providing a clear visual indication of open, closed, or throttled valve positions.
- Anti-Friction Thrust Bearing: Lower operational torque requirements make handwheel rotation effortless even under high differential pressures.
- Zero Maintenance Requirement: Eliminates routine gland packing tightening and stem repacking, drastically cutting down plant downtime and maintenance overheads.
Primary Industrial Applications
- Steam Distribution Lines: Isolation of high-pressure saturated and superheated steam mains.
- Thermal Fluid Systems: Heat transfer oil systems (Thermic Fluid Heaters) where leakage poses extreme fire hazards.
- Hazardous & Toxic Fluids: Safe handling of aggressive chemicals, ammonia, heat transfer media, and inflammable gases.
- Vacuum & Compressed Gas Networks: Leak-tight performance in vacuum lines and high-pressure industrial gas circuits.
