Double Bellows Seal
Product Overview
Spirax Sarco BSA and BSAT series are bellows sealed globe valves featuring double bellows seal design, suitable for steam, gas, liquid, condensate and water systems. The standard BSAT series is equipped with throttling disc and stem locking device, while the optional BSA series features flat disc design with optional balanced disc configuration. Products comply with European Pressure Equipment Directive 97/23/EC, and EN 10204 3.1 certificates are available for certain models (BSA2, BSA2T, BSA3, BSA3T) upon request at time of order.
Product Range and Options
Standard Series BSAT (with Throttling Disc and Stem Locking Device)
| Material | Model | Connection Type | Size Range (DN) | Options |
|---|---|---|---|---|
| Ductile Iron | BSA2T | PN16, PN25, PN40 | 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200 | R-PTFE Soft Seat |
| Cast Steel | BSA3T | ANSI 150, ANSI 300, KS 20 | 15, 20, 25, 40, 50, 80, 100, 150, 200 | R-PTFE Soft Seat |
Optional Series BSA (Flat Disc)
| Material | Model | Connection Type | Size Range (DN) | Options |
|---|---|---|---|---|
| Ductile Iron | BSA2 | PN16, PN25 | 125, 150, 200 | Balanced Disc |
| Cast Steel | BSA3 | PN40, ANSI 150, ANSI 300, KS 20 | 125, 150, 200 | Balanced Disc |
Dimensions/Weight (Approximate)
| Size | A(PN) | A(JIS/KS 10K) | A(JIS/KS 20K) | A(ANSI 150) | A(ANSI 300) | B | C | Weight(BSA2 BSA2T) | Weight(BSA3 DIN) | Weight(BSA3 ANSI 150) | Weight(BSA3 ANSI 300 JIS/KS 20K) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| DN15 | 130 | 133 | 152 | 108 | 152 | 205 | 125 | 4 | 4 | 5 | 6 |
| DN20 | 150 | 153 | 178 | 117 | 178 | 205 | 125 | 4 | 5 | 6 | 7 |
| DN25 | 160 | 163 | 200 | 127 | 203 | 217 | 125 | 5 | 6 | 8 | 9 |
| DN32 | 180 | 183 | - | - | - | 217 | 125 | 7 | 8 | - | - |
| DN40 | 200 | 203 | 224 | 165 | 229 | 243 | 200 | 10 | 11 | 10 | 11 |
| DN50 | 230 | 229 | 259 | 203 | 267 | 243 | 200 | 12 | 14 | 12 | 15 |
| DN65 | 290 | 293 | - | - | - | 263 | 200 | 16 | 19 | - | - |
| DN80 | 310 | 309 | 304 | 241 | 317 | 287 | 200 | 21 | 26 | 25 | 29 |
| DN100 | 350 | 349 | 340 | 292 | 356 | 383 | 315 | 36 | 44 | 41 | 49 |
| DN125 | 400 | 395 | - | - | - | 416 | 315 | 52 | 64 | - | - |
| DN150 | 480 | 479 | 428 | - | 445 | 450 | 315 | 75 | 88 | - | 94 |
| DN200 | 600 | 592 | 537 | - | 559 | 622 | 500 | 145 | - | - | 193 |
Sealing Class and Kv Values
Sealing Class
- Disc/seat sealing complies with EN 12266-1 Class A and ISO 5208 Class A
- BSA3(ANSI) complies with API 598 zero leakage standard
Basic Kv Values (BSA Series)
| Size (DN) | 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Kv Value | 4 | 7 | 12 | 19 | 30 | 47 | 77 | 120 | 193 | 288 | 410 | 725 | 1145 |
Maximum Allowable Pressure Differential for Throttling
| Size Range | Max Pressure Differential (bar) |
|---|---|
| DN15-DN80 | 2.0 |
| DN100-DN125 | 1.5 |
| DN150 | 1.0 |
| DN200-DN250 | 0.8 |
Note: When BSAT is used for throttling, exceeding the above pressure differential will increase noise and vibration
Material Specifications
| No. | Component | BSA2 / BSA2T | BSA3 / BSA3T (DIN) | BSA3 / BSA3T (ANSI) |
|---|---|---|---|---|
| 1 | Body | Ductile Iron EN-GJS-400-18-LT | Cast Steel 1.0619 (GSC 25N) | Cast Steel ASTM A 216 WCB |
| 2 | Bonnet | Ductile Iron EN-GJS-400-18-LT | Steel (DN15-DN80) DIN 17243 C 22.8; Steel (DN100-DN200) 1.0619 | Forged Steel (DN15-DN80) ASTM A 105; Cast Steel (DN100-DN200) ASTM A 216 WCB |
| 3 | Seat | Stainless Steel AISI 420 | Stainless Steel AISI 420 | Stainless Steel AISI 420 |
| 3-1 | Metal Seat Disc | Stainless Steel DIN 17440 X30 Cr13 | Stainless Steel DIN 17440 X30 Cr13 | Stainless Steel DIN 17440 X30 Cr13 |
| 4 | Soft Seat Disc | Stainless Steel DIN 17440 X30 Cr13 | Stainless Steel DIN 17440 X30 Cr13 | Stainless Steel DIN 17440 X30 Cr13 |
| 4-1 | Soft Seat Insert | R-PTFE 25% Carbon Filled | R-PTFE 25% Carbon Filled | R-PTFE 25% Carbon Filled |
| 5 | Bellows | Stainless Steel DIN 17440 X6 Cr Ni Ti 1810 | Stainless Steel DIN 17440 X6 Cr Ni Ti 1810 | Stainless Steel DIN 17440 X6 Cr Ni Ti 1810 |
| 6 | Stem | Stainless Steel AISI 420 | Stainless Steel AISI 420 | Stainless Steel AISI 420 |
| 7 | Handwheel | Pressed Steel BS 1449 CR4 | Pressed Steel BS 1449 CR4 | Pressed Steel BS 1449 CR4 |
| 8 | Stem Packing | Graphite | Graphite | Graphite |
| 9 | Bonnet Stud | Steel DIN 17420 24 Cr Mo 5 | Steel DIN 17420 24 Cr Mo 5 | Steel ASTM A 193 B7 |
| 9-1 | Bonnet Nut | Steel DIN 17420 Ck 5 | Steel DIN 17420 Ck 5 | Steel ASTM A 192 2 H |
| 10 | Body/Bonnet Gasket | Stainless Steel Reinforced Laminated Graphite | Stainless Steel Reinforced Laminated Graphite | Stainless Steel Reinforced Laminated Graphite |
| 11 | Lock Nut | DN15-DN80: Steel M8×14mm BS 3692 Gr.8.8; DN100-DN150: Steel M8×20mm; DN200-DN250: Steel M12×20mm | DN15-DN80: Steel M8×14mm BS 3692 Gr.8.8; DN100-DN150: Steel M8×20mm; DN200-DN250: Steel M12×20mm | DN15-DN80: Steel M8×14mm BS 3692 Gr.8.8; DN100-DN150: Steel M8×20mm; DN200-DN250: Steel M12×20mm |
Stroke Limiter Configuration (BSAT)
| Size Range (DN) | Required Hex Bolt Specification |
|---|---|
| 15-80 | M8×50mm |
| 100-150 | M12×75mm |
| 200-250 | M12×100mm |
Note: Stroke limiter requires customer-supplied standard bolts and nuts; handwheel nut has pre-threaded mounting hole
Balanced Disc Application Conditions
| Size (DN) | Applicable Pressure Differential (bar) |
|---|---|
| 125 | >25 |
| 150 | >17 |
| 200 | >10 |
| 250 (BSA2 only) | >6 |
Body Design Conditions
BSA2, BSA2T
| Design Parameter | PN16 | JIS/KS 10K | PN25 | JIS/KS 20K |
|---|---|---|---|---|
| Maximum Allowable Pressure (PMA) | 16 bar g | 16 bar g | 25 bar g | 25 bar g |
| Maximum Allowable Temperature (TMA) | 350°C | 350°C | 350°C | 350°C |
| Max Operating Pressure - Saturated Steam (PMO) | 14.7 bar g | 14.7 bar g | 22.3 bar g | 22.3 bar g |
| Max Operating Temperature (TMO) - Soft Seat | 230°C | 230°C | 230°C | 230°C |
| Max Operating Temperature (TMO) - Metal Seat | 350°C | 350°C | 350°C | 350°C |
| Minimum Operating Temperature | -10°C | -10°C | -10°C | -10°C |
| Design Max Cold Hydrostatic Test Pressure | 24 bar g | 24 bar g | 38 bar g | 38 bar g |
BSA3, BSA3T
| Design Parameter | ANSI 150 | ANSI 300 | JIS/KS 20K |
|---|---|---|---|
| Maximum Allowable Pressure (PMA) | 19.6 bar g | 51 bar g | 34 bar g |
| Maximum Allowable Temperature (TMA) | 425°C | 425°C | 425°C |
| Max Operating Pressure - Saturated Steam (PMO) | 14 bar g | 41.6 bar g | 30.7 bar g |
| Max Operating Temperature (TMO) - Soft Seat | 230°C | 230°C | 230°C |
| Max Operating Temperature (TMO) - Metal Seat | 425°C | 425°C | 425°C |
| Minimum Operating Temperature | -29°C | -29°C | 0°C |
| Design Max Cold Hydrostatic Test Pressure | 31 bar g | 77 bar g | 50 bar g |
Installation and Maintenance
Installation Tips
- Install according to the flow direction arrow on the valve body
- Position handwheel for convenient operation
- Refer to the Installation and Maintenance Guide (IM-P137-02) provided with the product for detailed installation steps
Product Disposal
- This product is recyclable and proper disposal will not cause ecological problems
Spare Parts List
Available Spare Parts (Supplied as Sets)
| Spare Part Name | Included Component Numbers |
|---|---|
| Body/Bonnet Gasket and Stem Packing | 10, 8 (2 sets) |
| Stem and Bellows Assembly (specify BSA/BSAT) | 5, 6, 8, 10 |
| Disc and Other Options (specify valve model) | 4, 8, 10 |
Ordering Information
Ordering Examples
- Spirax Sarco DN25 BSA2T Bellows Sealed Globe Valve, PN16 or PN25 flanged connection
- Body/Bonnet Gasket and Stem Packing for Spirax Sarco DN15 BSA2T PN16 Bellows Sealed Globe Valve
Special Notes
- If EN 10204 3.1 certificate is required, specify at time of order
- If upstream/downstream pressure differential exceeds balanced disc application conditions, must select model with "BD" designation (e.g., BSA2-BD)
- Specify valve model and size when ordering spare parts
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