Open Die Forged Cryogenic Floating Ball Valve

Descrizione

TECHNICAL DATA SHEET

Forged Stainless Steel Cryogenic Floating Ball Valve
Series: DQ41F/Y / DQ61F/Y
Models: Reduced Bore / Full Bore, Side-Entry (Split Body)

1. PRODUCT OVERVIEW

This forged stainless steel cryogenic ball valve is specifically engineered for reliable shut-off and flow control of liquefied gases and cryogenic fluids down to -196°C. Designed in accordance with BS 6364, ISO 28921-1, and MSS SP-134 standards, it features a two-piece bolted body construction with extended bonnet and fully forged austenitic stainless steel components (ASTM A182 F304/F304L/F316L) to eliminate porosity and ensure structural integrity under extreme thermal cycling .

Caratteristiche principali:

• 100% Forged Body Construction: ASTM A182 F304/F304L stainless steel, no cast defects, superior low-temperature impact toughness .
• Extended Bonnet (Long Neck): Minimum 250mm neck length for DN50 and above, positions stem packing at ambient temperature, prevents ice formation, and allows insulation application .
• Cryogenic Stabilization Treatment: All pressure-containing parts undergo deep cryogenic treatment (LN₂ immersion, -196°C soak for 2-6 hours, 2-3 cycles) to stabilize microstructure and relieve machining stresses .
• Blow-out Proof Stem: Integrally forged stem with anti-blowout shoulder, anti-static device (spring-loaded contact) per ISO 28921-1 .
• Low Emission Packing: Live-loaded disc spring + graphite/RPTFE packing system, meets ISO 15848-1 Class B fugitive emission requirements .
• Cavity Pressure Relief: Upstream seat is pressure-relieving design to prevent body cavity over-pressurization due to cryogenic fluid vaporization .
• Full Traceability: Positive Material Identification (PMI) and EN 10204 Type 3.1 material certification available .

2. DESIGN STANDARDS & SPECIFICATIONS

3. GENERAL TECHNICAL PARAMETERS

4. MATERIALS OF CONSTRUCTION (FORGED STAINLESS STEEL)

Alternative Forged Materials (Upon Request):

• A182 F316/F316L: Enhanced pitting corrosion resistance
• A182 F321: Stabilized grade for higher intermittent temperatures
• Inconel 625 / Hastelloy C-276: For extreme low temp (< -196°C) + high corrosion
• A352 LC3 / LCB: Cast low carbon steel (not forged, for non-SS requirements)

5. CRYOGENIC TREATMENT & TESTING

Cryogenic Stabilization Process:

1. All rough-machined forged components (body, bonnet, ball, stem) are immersed in liquid nitrogen (-196°C).
2. Soaking time: 2-6 hours depending on mass (minimum 2 hours per cycle) .
3. Components are returned to ambient temperature naturally (no forced heating).
4. Process repeated for minimum 2 cycles .
5. Final precision machining after stabilization to ensure dimensional stability at cryogenic service.

Purpose:

• Transforms retained austenite
• Relieves residual stresses from forging/welding
• Prevents dimensional changes and seal leakage during thermal cycling

Impact Testing:

• Charpy V-Notch test per ASTM A370
• Acceptance criteria: ≥ 41J (average) at -196°C for F304L
• AOKAVI standard: ≥ 50J at -196°C

6. DIMENSIONS & CONNECTIONS (ASME CLASS 150/300 – REFERENCE)

6.1 Flanged Type (DQ41F/Y) – PN16/PN40 / Class 150/300

Unit: mm (Reference dimensions – subject to manufacturer design)

Notes:

• Flange drilling per ASME B16.5 (Class 150 / 300). For PN16/PN40, dimensions vary per EN 1092-1.
• Bonnet extension length per BS 6364: Minimum 250mm for DN50 and above; actual H dimension includes operator clearance .
• Weight shown for Class 150 carbon steel body; SS body slightly heavier.

6.2 Socket Weld / Threaded Type (DQ61F/Y) – NPT/BSPT/SW

Unit: mm

Source: 

7. PRESSURE-TEMPERATURE RATING

Forged A182 F304/F304L – ASME B16.34

Critical Notes:

• Floating ball design is limited to Class 300 maximum due to stem thrust loading .
• For Class 600 and above, trunnion-mounted cryogenic ball valve design is required.
• Pressure rating at -196°C is derated per ASME B16.34 and BS 6364 requirements .

8. PERFORMANCE & LEAKAGE TESTS

9. OPERATING TORQUE (REFERENCE @ -196°C)

Notes:

• Torque increases significantly with pressure differential and seat material (PCTFE higher than RPTFE).
• Safety factor for actuator sizing: 1.3 – 1.5 for pneumatic, 1.5 – 2.0 for electric .
• Values shown for RPTFE seats, clean media, DN50 tested per .

10. DESIGN FEATURES & CRYOGENIC SPECIALTIES

Extended Bonnet (Long Neck):

• Mandatory for service below -50°C .
• Positions stem packing and actuator at ambient temperature zone.
• Prevents ice formation and lubrication solidification.
• Standard neck length: 250mm for DN50, scaled proportionally for other sizes.

Pressure Relief Mechanism:

• Floating ball design inherently allows upstream seat to act as pressure relief.
• Prevents body cavity overpressure due to liquid vaporization (cryogenic pumping effect) .
• For fixed ball designs, optional internal relief valve or self-relieving seat.

Dispositivo antistatico:

• Required per ISO 28921-1 and BS 5353 for flammable cryogenic media (LNG, ethylene, etc.).
• Spring-loaded plunger continuously grounds ball to body.

Oxygen Service Cleaning:

• Optional degreasing and cleaning per CGA G-4.1 (for liquid oxygen service).
• Chlorine-free packaging and labeling .

11. APPLICATIONS & INDUSTRY USE

12. QUALIFICATION & CERTIFICATION

13. SELECTION & ORDERING INFORMATION

To ensure correct valve selection for your cryogenic application, please specify:

1. Model: DQ41F (Flanged) / DQ61F (SW/NPT) / DQ47F (Gear)
2. Size (DN/NPS): e.g., DN50 (2″)
3. Pressure Class: Class 150 / 300 / PN16 / PN40
4. Materiale del corpo: A182 F304/F304L (Forged SS) — standard for -196°C
5. Ball/Stem Material: A182 F304/F304L
6. Seat Material: RPTFE / PCTFE / PEEK (specify)
7. End Connection: RF flange, RTJ flange, NPT, BSPT, SW, BW
8. Design Temperature: -196°C / -101°C / -46°C
9. Service Media: LNG / LN₂ / LO₂ / Ethylene / Other (specify)
10. Operazione: Manual Lever / Gear / Pneumatic / Electric
11. Special Requirements:

• Cryogenic test with BS 6364 certificate
• Oxygen cleaning (CGA G-4.1)
• Anti-static device
• Fire-safe design (API 607)
• NACE MR0175
• Extended bonnet length (custom)
• PMI testing
• EN 10204 3.1 material certs

GARANZIA:

SAVVY VALVES si impegna a fornire una qualità di prodotto eccezionale e un servizio post-vendita senza pensieri. Le nostre valvole sono garantite per una durata minima di 12 mesi, durante i quali forniremo gratuitamente tutti i pezzi di ricambio necessari e istruzioni di manutenzione dettagliate. Durante il periodo di garanzia, in caso di danni non causati dall'uomo, sostituiremo i componenti gratuitamente e forniremo supporto tecnico professionale. Dopo la scadenza della garanzia, i clienti dovranno pagare solo il costo dei pezzi di ricambio, beneficiando comunque di servizi di manutenzione scontati. Il nostro obiettivo è aiutare i clienti a ridurre i costi operativi e a migliorare l'efficienza produttiva attraverso una qualità affidabile e un supporto post-vendita completo. Che si tratti di richieste tecniche o di esigenze di manutenzione, il nostro team di esperti risponderà tempestivamente per garantire che il vostro sistema di valvole mantenga prestazioni ottimali in ogni momento.