DN100-PN25 Bellow Seal Globe Valve
Description
Technical Datasheet: Bellows Seal Globe Valve
Product Name: Bellows Seal Globe Valve (波纹管截止阀)
Connection: Flanged Ends
Nominal Size: DN100 (4″)
Nominal Pressure: PN25
Body Construction: Cast Steel / Forged Steel
1. General Design Features
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Type: Bellows-sealed globe valve, straight-through pattern (直通式) .
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Seal Design: Double sealing system. Primary seal is a multi-ply metal bellows welded to the stem, preventing external leakage. Secondary backup packing (graphite) provides additional safety .
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Bonnet Design: Bolted bonnet construction for easy maintenance .
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Back Seat: Standard back seat design allows for repacking under pressure (in open position) and protects the packing from system flow .
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Operation: Rising stem with non-rising handwheel (indicates valve position) .
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Flow Direction: Flow direction is typically “above the disc” (flow closes) for improved shut-off capability .
2. Applicable Standards & Specifications
| Item | Standard / Specification |
|---|---|
| Design & Manufacturing | DIN 3356, EN 137-1, GB/T 12235, ASME B16.34 (applicable) |
| Face-to-Face Dimensions | DIN 3202 / EN 558-1 Series 1 |
| Flange Connection | DIN 2543-2456 / EN 1092-1 (PN25) |
| Pressure-Temperature Rating | DIN 2401 / ASME B16.34 |
| Testing & Inspection | DIN 3230 / EN 12266-1 |
| Bellows Standard | ISO 15761 / BS EN 137-1 |
3. Operating Parameters
| Item | Specification |
|---|---|
| Size | DN100 |
| Pressure Rating | PN25 *(approx. 25 bar / 2.5 MPa / 363 PSI)* |
| Shell Test Pressure | 38 bar (Hydrostatic, 1.5 x PN) |
| Seat Test Pressure | 27.5 bar (Hydrostatic, 1.1 x PN) |
| Temperature Range | -10°C to +400°C (depending on body and bellows material) |
| Suitable Media | Steam, thermal oil, hot water, aggressive and hazardous fluids |
| Leakage Rate | Zero leakage to atmosphere (bellows seal) |
4. Bill of Materials (Typical Material Selection)
Note: Material selection depends on the fluid temperature and corrosivity. Two common configurations are listed below.
| Item | Part Name | Carbon Steel Configuration | Stainless Steel Configuration |
|---|---|---|---|
| 1 | Body | GS-C25 / A216 WCB (Carbon Steel Casting) | 1.4408 / A351 CF8M (SS Casting) |
| 2 | Bonnet / Yoke | GS-C25 / A216 WCB | 1.4408 / A351 CF8M |
| 3 | Disc / Valve Plug | 20Cr13 + Stellite (Hardfaced) | SS316 + Stellite |
| 4 | Seat Ring | 13Cr / A105 + Stellite | SS316 + Stellite |
| 5 | Bellows | AISI 304 / 316 (Stainless Steel) | AISI 316L / C276 (Hastelloy) |
| 6 | Stem | AISI 420 / 20Cr13 (Stainless Steel) | AISI 316 / 1.4401 |
| 7 | Gasket (Body/Bonnet) | Spiral Wound (Graphite + SS304) | Spiral Wound (Graphite + SS316) |
| 8 | Packing (Backup) | Graphite Rings | Graphite Rings |
| 9 | Studs & Nuts | ASTM A193 B7 / A194 2H | ASTM A193 B8 / A194 8 |
| 10 | Handwheel | Ductile Iron / Fabricated Steel | Ductile Iron / SS |
5. Dimensional Data (DN100 PN25)
Note: Dimensions are standard references per DIN/EN standards. Verify with manufacturer’s drawing.
| Dimension | Value (mm) | Notes / Reference Standard |
|---|---|---|
| Face-to-Face Length (L) | 350 mm | DIN 3202 / EN 558-1 Series 1 (approx.) |
| Overall Height (H) | 350 – 381 mm | Handwheel closed position (approx.) |
| Flange Diameter (D) | 235 mm | DIN EN 1092-1 (PN25) |
| Bolt Circle Diameter (K) | 190 mm | Standard for DN100 PN25 |
| Number of Bolt Holes | 8 | Standard for DN100 PN25 |
| Bolt Hole Diameter (L) | 22 mm | Standard for M20 bolts |
| Weight | 35 kg – 48 kg | Depends on material (CS vs SS) and pressure rating |
6. Inspection & Testing Procedure
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Shell Test: Valve partially open. Hydrostatic test at 1.5 times PN (38 bar) . Check body and bonnet joints for leaks .
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Seat Test: Valve closed. Hydrostatic test at 1.1 times PN (27.5 bar) . Check for leakage across the seat.
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Bellows Seal Test: Specific test to ensure the bellows integrity (usually with air or helium leak detection).
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Backseat Test: Verify backseat seal function when valve is fully open.
7. Features & Benefits
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Zero Leakage: The welded metal bellows eliminates stem leakage, reducing maintenance and improving safety for toxic or expensive media .
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Extended Service Life: Bellows compensates for thermal expansion and has high cycle life.
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Energy Savings: Prevents loss of valuable fluids or steam.
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Maintenance Friendly: Backup packing allows for sealing even in the unlikely event of bellows failure .
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ISO 5211 Mounting: Top flange (if specified) allows for easy mounting of actuators.
