Cryogenic Top Entry Trunnion-mounted Ball Valves

Description

TECHNICAL DATA SHEET: TOP ENTRY TRUNNION-MOUNTED (FIXED BALL) CRYOGENIC BALL VALVE

1. Valve Identification:

• Type: Top Entry, Full Port (FP) / Reduced Port (RP), Trunnion-Mounted (Fixed Ball) Design
• Operation: Gear Operated / Extended Stem with Actuator (Pneumatic, Electric, Hydraulic)
• Design Standard: BS 6364 / ISO 28921-1 / MSS SP-134 / API 6D (Annex F – Cryogenic)
• Face-to-Face: ASME B16.10 / ISO 5752 Series 11 (Cryogenic Extended) / BS 6364 Table 1
• End Connection: Flanged (RF, RTJ) ASME B16.5 / ASME B16.47 / EN 1092-1 / ISO 7005 / BW (ASME B16.25)
• Body Construction: Top Entry (Single Piece Body with Removable Bonnet/Cover)

2. Design Parameters & Service:

• Size Range: DN 50 (2″) to DN 600 (24″) [Typical for fixed ball, specify range]
• Pressure Class: ASME: 150, 300, 600, 900, 1500 | PN: 10, 16, 25, 40, 63, 100 [Specify]
• Temperature Range:
• Standard Design: -196°C (-320°F) [Liquid Nitrogen]
• Extended Design: Down to -254°C (-425°F) [Liquid Hydrogen]
• Upper Limit: +80°C (+176°F) (Dependent on seals)
• Design Pressure: Per ASME B16.34 at minimum design temperature (incl. low-temp derating).
• Service: LNG, LIN, LAR, LOX, LHe, LCO₂, Ethylene, High-Pressure Cryogenic Gases.

3. Body & Bonnet (Cover):

• Material: A351 CF8M (316) / CF3M (316L) – Standard. A350 LF2 (clad) / Nickel Alloys (LOX/Corrosive).
• Cryogenic Treatment: All pressure parts thermally stabilized per BS 6364.
• Extended Bonnet: Mandatory. Length per BS 6364 Table 1 or custom. Includes drip plate.

4. Ball & Trunnions:

• Ball Material: AISI 316/316L (Std), 17-4PH (H1150M) (HP), Inconel 718/625 (Corr/LOX).
• Trunnion Material: Matches ball or higher strength (17-4PH, Inconel). Mechanically secured to body.
• Surface Finish: Ra ≤ 0.4 µm (16 µin) on sealing surfaces.
• Design: Fixed to trunnions. Zero shaft load, minimal friction, high-pressure stability.

5. Seats & Sealing System:

• Type: Spring + Line Pressure Energized (Piston Effect), Dual-Sealing.
• Seat Material:
• Primary: Reinforced PTFE (RPTFE) / PCTFE (Kel-F) (Std, Cryo-Tight).
• Fire-Safe Option: Graphite/Metal seats with RPTFE primary seal (*API 607/6FA*).
• Design:
• Bidirectional Sealing. Line pressure forces seats against ball.
• Cavity Relief: Automatic pressure relief through seats upon opening.
• Spring Preload: Maintains seal at zero/low pressure.

6. Stem:

• Material: A182 F316/F316L (Std), 17-4PH (H1150M) (HP), Monel K500/Inconel 718 (LOX/Corr).
• Design: Floating Stem (decoupled from seat load), Blowout-Proof, Anti-Static per BS 6364.
• Stem Seals:
• Primary Seal (Cryo Zone): Low-temp PTFE chevrons/graphite foil.
• Secondary Seal (Ambient): Live-loaded graphite packing. Fire-safe design.

7. Bearings & Thrust Control:

• Trunnion Bearings: Self-lubricating, cryogenic-compatible (Rulon® AR, Turcon®).
• Thrust Washers: PTFE composites on ball/seat interface.
• Function: Absorb line thrust, minimize operating torque, prevent galling.

8. Sealing & Leakage:

• Seat Leakage: Class VI (Bubble-Tight) per ISO 5208/API 598 (Tested cryogenically).
• Stem Leakage: ISO 15848-1 Class B or better (Ambient & Cryo).
• Fire Safe: API 607/6FA / ISO 10497 (Optional).
• Anti-Static: BS 6364 / ISO 28921-1 compliant.

9. Operation:

• Operating Torque: Consistently low (even at high ΔP). [Specify max torque at cryo temp].
• Rotation: 90° quarter-turn. Open: CCW (Standard).
• Actuation: Gearbox recommended. Pneumatic/Electric with extended kit.

10. Cryogenic Testing (Per BS 6364 / ISO 28921-1):

• Cryogenic Seat Test: Submerged in LN₂ at design pressure.
• Thermal Cycling: 5-15 cycles (ambient ↔ cryo) + leakage test.
• Operation Test: Functionality at cryo temp.
• Anti-Static Test: Continuity verified.
• High-Pressure Gas Test: Optional (e.g., per ISO 17292).

11. Features & Advantages (vs. Floating Ball):

• High-Pressure Capability: Stable sealing up to ASME 1500 class.
• Reduced Operating Torque: Trunnions absorb thrust → smaller actuators.
• Zero Shaft Load: Stem only transmits rotation → longer stem/seal life.
• Bidirectional Sealing & Cavity Relief: Inherent design safety.
• Stable Seating: Minimal seat deformation under thermal stress.
• Wider Size Range: Suitable for larger diameters (DN 300+).

12. Applications:

• LNG Liquefaction & Storage Tanks
• High-Pressure Cryogenic Gas Transmission (e.g., Pipeline Compressor Stations)
• Large-Diameter Transfer Lines (>DN 300)
• Air Separation Units (ASUs) – LOX/LIN/LAR Service
• Liquid Hydrogen Infrastructure
• Ethylene Crackers & Storage

13. Optional Features:

• Double Block & Bleed (DBB) via body vents
• Fire-Safe Design (API 607/6FA)
• Oxygen Service Cleaning (CGA G-4.1/EIGA DOC 33/18)
• Custom Stem Extensions for thick insulation
• Partial Stroke Test (PST) capability
• Positioners/Limit Switches

14. Certifications & Compliance:

• Design: BS 6364, ISO 28921-1, API 6D Annex F, PED 2014/68/EU
• Materials: EN 10204 3.1/3.2, NACE MR0175 (if sour)
• Testing: Certified Cryogenic Test Reports
• Quality: ISO 9001:2015

Key Distinctions from Floating Ball Design:

1. Mechanical Support: Ball is rigidly held by trunnions (not floating on stem).
2. Seat Load: Line pressure energizes seats → sealing improves with pressure.
3. Torque: Significantly lower and stable across pressure ranges.
4. Pressure Rating: Suitable for ASME 1500+ classes.
5. Cavity Management: Automatic pressure relief without external ports.
6. Stem Function: Pure rotational force only (no axial thrust).

Let me know if you need deeper technical focus on trunnion mechanics, fire-safe options for fixed ball, or specific cryogenic test protocols.

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.