1-1/2″ – 300LB Cryogenic Bellows Seal Gate Valve
Description
Technical Datasheet: Cryogenic Bellows Seal Gate Valve
Product Name: Cryogenic Bellows Seal Gate Valve
Connection: Flanged Ends (ASME B16.5)
Nominal Size: 1.5 inches (DN40)
Pressure Rating: Class 300 LB
Body Material: Stainless Steel (CF8 / CF8M / CF3M)
1. General Design Features
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Type: Bellows-sealed gate valve, specifically designed for cryogenic services.
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Service Temperature: Designed for cryogenic applications down to -196°C (-320°F) (LNG, Liquid Nitrogen, Liquid Oxygen) .
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Seal Design: Zero-leakage to atmosphere via a primary welded metal bellows. A secondary graphite packing provides backup sealing.
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Bonnet Design: Extended bonnet construction to ensure the stem packing and bellows assembly remain above 0°C, preventing ice formation and seal failure .
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Cryogenic Treatment: All pressure-containing parts are subjected to deep cryogenic treatmentat -196°C to ensure dimensional stability and prevent austenite transformation .
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Back Seat: Integral back seat allows for repacking under pressure (if bellows fails) and protects the packing from direct media flow.
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Operation: Rising stem with non-rising handwheel for visual position indication.
2. Applicable Standards & Specifications
| Item | Standard / Specification |
|---|---|
| Design & Manufacturing | BS 6364 (Specification for valves for cryogenic service) , API 600, ASME B16.34, GB/T 44916 |
| Face-to-Face Dimensions | ASME B16.10 |
| Flange Connection | ASME B16.5 (Class 300 LB) |
| Pressure-Temperature Rating | ASME B16.34 |
| Testing & Inspection | BS 6364, API 598, ISO 5208, GB/T 24925 |
| Bellows Standard | ISO 15761 / BS EN 137-1 |
| Fugitive Emissions | ISO 15848-1 (Optional) |
3. Operating Parameters
| Item | Specification |
|---|---|
| Size | 1.5 inches (DN40) |
| Pressure Rating | Class 300 LB (Max 51 bar @ ambient per ASME B16.34) |
| Shell Test Pressure | 77 bar (Hydrostatic, 1.5 x Class 300 rating) |
| Seat Test Pressure | 56 bar (Hydrostatic, 1.1 x Class 300 rating) |
| Design Temperature | -196°C to +80°C (Cryogenic service) |
| Suitable Media | LNG, LPG, Liquid Nitrogen (LN₂), Liquid Oxygen (LO₂), Liquid Argon, Ethylene |
| Leakage Rate | Zero leakage to atmosphere (bellows seal) |
4. Bill of Materials (Stainless Steel Cryogenic Design)
Note: Materials are selected to meet BS 6364 cryogenic requirements .
| Item | Part Name | Material Specification |
|---|---|---|
| 1 | Body | ASTM A351 CF8M (316 Stainless Steel Casting) |
| 2 | Bonnet (Extended) | ASTM A351 CF8M (316 Stainless Steel Casting) |
| 3 | Gate / Wedge | ASTM A182 F316L with Stellite hardfacing (Co-Cr alloy) |
| 4 | Seat Ring | Stellite hardfaced (integral with body) |
| 5 | Bellows | ASTM A240 316L (Multi-ply Stainless Steel) |
| 6 | Stem | ASTM A182 F316L (Austenitic Stainless Steel) |
| 7 | Body Gasket | Spiral Wound 316SS + Graphite |
| 8 | Packing | Graphite Ribbon Rings (Backup seal) |
| 9 | Bonnet Bolting | ASTM A193 B8 / A194 8 (Stainless Steel) |
| 10 | Handwheel | Ductile Iron / Fabricated Steel |
5. Dimensional Data (1.5″ – Class 300 LB)
Note: The extended bonnet length (H) is critical for cryogenic service to maintain the packing box temperature above 0°C.
| Dimension | Value (mm / inches) | Standard / Reference |
|---|---|---|
| Face-to-Face Length (L) | 368 mm (14.50 inches) | ASME B16.10 |
| Extended Bonnet Height (H) | Approx. 580 – 620 mm | Required to keep stem seal above freezing point (BS 6364 requirement) |
| Flange Diameter (D) | 190 mm (7.48 inches) | ASME B16.5 (Class 300) |
| Bolt Circle Diameter (K) | 152.4 mm (6.00 inches) | ASME B16.5 (Class 300) |
| Number of Bolt Holes | 8 | ASME B16.5 (Class 300) |
| Bolt Hole Diameter | 22 mm (0.88 inches) | For 3/4″ bolts |
| Weight | Approx. 30 – 40 kg | Dependent on bonnet extension length |
6. Special Requirements for Cryogenic Service (Per BS 6364)
6.1 Deep Cryogenic Treatment
All stainless steel pressure parts shall be thermally cycled to -196°C to stabilize the austenitic structure and prevent dimensional changes during operation .
6.2 Extended Bonnet (Cold Box Design)
The bonnet length must be sufficient to ensure the temperature at the stuffing box is maintained above 0°C to prevent ice formation on the stem and bellows .
6.3 Stellite Hardfacing
Seat and wedge surfaces must be overlaid with Stellite (Cobalt-Chromium alloy) to prevent galling and seizure at cryogenic temperatures .
6.4 Cleanliness & Degreasing
Valves for oxygen service (LO₂) require oxygen cleaning to remove all hydrocarbons and prevent combustion risks.
7. Inspection & Testing Procedure (Per BS 6364)
| Test Type | Procedure | Acceptance Criteria |
|---|---|---|
| Shell Test | Hydrostatic test at 1.5 x rated pressure (77 bar) . | No visible leakage through pressure boundary |
| Seat Test (Ambient) | Hydrostatic test at 1.1 x rated pressure (56 bar) . | No visible leakage across seat |
| Cryogenic Test | Test at -196°C per BS 6364 Clause 8 | Valve must operate without seizure; leakage rate ≤ 100 mm³/s (per nominal size) |
| Bellows Integrity | Helium leak test | Leak rate ≤ 1×10⁻⁶ mbar·L/s |
| Operational Torque | Measure at ambient and cryogenic temp | Torque must be within design limits |
8. Features & Benefits
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Zero Fugitive Emissions: Welded metal bellows eliminates stem leakage, critical for volatile cryogenic fluids.
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BS 6364 Certified: Full compliance with international cryogenic valve standard .
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No Icing: Extended bonnet prevents ice formation on stem seals .
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Long Cycle Life: Bellows design handles thermal cycling without failure.
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Stellite Protection: Prevents galling of stainless steel at cryogenic temperatures .
Thank you for the correction. This version now uses the correct industry terminology “Cryogenic” and references the proper standard (BS 6364).
