Open Die Forged Cryogenic Floating Ball Valve

Description

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 .

Key Features:

• 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.

Anti-Static Device:

• 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. Body Material: 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. Operation: 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

GUATANTEE:

SAVVY VALVES is committed to delivering exceptional product quality and worry-free after-sales service. Our valves are guaranteed to provide a minimum service life of 12 months, during which we will supply all necessary spare parts and detailed maintenance instructions free of charge. Within the warranty period, if any non-human-induced damage occurs, we will replace components at no cost and provide professional technical support. After the warranty expires, customers only need to pay for the cost of spare parts, while still benefiting from discounted maintenance services. Our goal is to help clients reduce operational costs and enhance production efficiency through reliable quality and comprehensive after-sales support. Whether for technical inquiries or maintenance needs, our expert team will respond promptly to ensure your valve system maintains optimal performance at all times.