Successful Application of Ring-11 Tuning Fork Level Switch in LNG Spherical Tank Level Measurement

1. Project Background

Liquefied Natural Gas (LNG) is a critical component of the clean energy sector, and the safety of its storage directly affects industrial operational safety and production efficiency. LNG spherical tanks are typically designed for low-temperature storage (around -40°C), with large volumes and complex geometries. These characteristics place stringent requirements on the reliability and stability of level measurement, making top-mounted Tuning Fork Level Switches like the Ring-11 an ideal solution for accurate and dependable point-level detection.

Traditionally, users have relied on international brands such as VEGA, Endress+Hauser (E+H), Rosemount, and Siemens for level measurement solutions. While these imported instruments are reliable, they are expensive and have limitations in terms of localized technical support, installation response speed, and cost control.

To address these challenges, Shenzhen Jiwei Automations Ltd leveraged its in-house R&D and patented technologies to provide the Ring-11 top-mounted tuning fork level switch solution, successfully replacing multiple international brand products and achieving highly reliable, cost-effective LNG spherical tank level measurement.

2. Overview of Ring-11 Tuning Fork Level Switch

The Ring-11 tuning fork level switch uses the vibrating fork principle, detecting liquid level changes by monitoring vibration frequency variations, enabling reliable point level measurement. Key advantages include:

• Cryogenic Compatibility: Operates reliably at -40°C, ensuring LNG level measurement stability.
• Top-Mounted Design: No tank internal space required, ideal for spherical tanks, reactors, or tanks with limited top space.
• High Anti-Interference Capability: Unaffected by steam, light foam, or agitators, ensuring accurate level detection.
• SIL2 Safety Certification: Meets industrial safety requirements for hazardous areas.
• Low Maintenance: Non-contact design without mechanical moving parts, ensuring long-term reliability.
• Wide Compatibility: Supports DPDT or SPST outputs, directly integrating with DCS/PLC systems for high and low level alarms and control.

With maturity, stability, and high cost-performance, Ring-11 has become the preferred domestic alternative to imported LNG level instruments.

3. Project Requirements and Technical Challenges

For the LNG spherical tank level measurement project, the client required:

• Low-Temperature Adaptation: Continuous stable operation at approximately -40°C.
• High Reliability: Large tank volume demands precise level measurement to prevent safety hazards.
• Anti-Interference: Tank top piping, vents, and safety valves could affect level detection.
• Fast Response and High Accuracy: Immediate switching at setpoints to ensure reliable automatic control.
• Easy Installation and Maintenance: Quick, simple installation with low long-term maintenance requirements.
• Imported Brand Replacement: Reduce procurement costs while maintaining measurement reliability, replacing VEGA, E+H, Rosemount, and Siemens instruments.

In practice, radar level meters are difficult to install in spherical tanks with limited top space, while float level meters are affected by cryogenic liquids and require high maintenance. Ring-11 tuning fork level switches effectively address these challenges.

4. Ring-11 Solution Design

For LNG spherical tanks, the Jiwei R&D team proposed the following design:

Probe Material Selection

• Probe made of 316L stainless steel with polished surface, ensuring no freezing or sticking at -40°C.
• Sealing rings use low-temperature fluororubber for long-term reliability.

Top-Mounted Installation Design

• Ring-11’s top-mounted design requires no internal tank space and allows fast installation.
• Installation locations optimized with CFD simulations to ensure immediate level detection.
• Multi-point installation enables high level alarm, low level alarm, and automatic control.

Signal Output and Safety Design

• Supports DPDT, SPST, two-wire, transistor, and NAMUR outputs, compatible with PLC/DCS systems for automatic control and alarms.
• SIL2 certified (certificate verifiable via CNCA), suitable for hazardous area liquid control.
• Optional explosion-proof design complies with industrial fire safety standards.

On-Site Commissioning and Maintenance

• Top-mounted Ring-11 allows fast on-site commissioning, completing all level point settings in under 30 minutes.
• Non-contact design eliminates mechanical components, reducing maintenance frequency and difficulty.

Imported Brand Replacement Strategy

• On-site testing confirmed that Ring-11 successfully replaced VEGA, E+H, Rosemount, and Siemens products.
• Significant cost advantages while providing local technical support and fast spare part supply.

5. On-Site Installation and Commissioning

At the LNG spherical tank site, Jiwei engineers completed:

• Multi-Point Level Deployment: Top-mounted high and low-level tuning fork switches for full-range level monitoring.
• Cryogenic Environment Verification: Continuous monitoring at -40°C for over 480 hours, demonstrating accurate and reliable switching.
• Compatibility Testing: Successfully integrated with on-site PLC/DCS systems for automated level control and remote alarms.

6. Project Results and Client Feedback

• High Reliability: Engineers reported continuous operation for over 12 months without failure or false alarms, with stable and reliable level monitoring.
• Successful Replacement of International Brands: VEGA, E+H, Rosemount, and Siemens level switches were gradually replaced. Performance comparison showed Ring-11 response speed and consistency comparable or slightly superior to the imported brands.
• Reduced Operational Costs: Maintenance personnel noted that the top-mounted, non-mechanical design simplified inspections and commissioning, reducing overall maintenance costs by approximately 30%.
• Enhanced Safety: High and low-level alarms responded promptly, helping prevent overfilling or dangerously low liquid levels.
• High Customer Satisfaction: Operators praised Ring-11 for ease of installation, efficient commissioning, stable operation, and intuitive handling, fully meeting LNG tank level control requirements.

7. Jiwei Technical Advantages

• Independent R&D and Patents: Over 20 national patents covering fork probe design, low-temperature anti-sticking coating, and intelligent echo algorithms.
• Cryogenic High Reliability: Probe materials, seals, and anti-sticking surface treatment ensure stable operation at -40°C.
• Fast Installation and Commissioning: Top-mounted design enables efficient on-site setup.
• Local Support Advantage: Complete supply chain and after-sales system for rapid response, surpassing imported brands’ local service.
• Successful Replacement of International Brands: Ring-11 has replaced VEGA, E+H, Rosemount, and Siemens in LNG, chemical, and energy projects with reliable performance and high cost-effectiveness.

8. Conclusion

The Ring-11 tuning fork level switch, with its top-mounted design, cryogenic adaptation, anti-interference capability, and high reliability, perfectly meets LNG spherical tank level measurement requirements. It enables multi-point level control and high/low-level alarms, reduces procurement and operational costs, and successfully replaces VEGA, E+H, Rosemount, and Siemens instruments. This project demonstrates Shenzhen Jiwei Automations Ltd’s technical strength, engineering capability, and competitiveness in high-end level measurement.

Ring-11’s successful application provides a replicable solution for domestic LNG tank level measurement while showcasing Jiwei’s innovation and leadership in advanced level measurement instrumentation.