Case Overview
An LNG tank contractor building membrane-containment tanks needed Invar36 strip with measured, verifiable thermal expansion. Membrane welds had to follow tank contraction at -162°C without cracking, while nominal “Invar” claims unsupported by tests were unacceptable to the contractor’s design authority.
DZX qualified with batch-measured CTE Invar36 strip, typically ≤ 1.5 × 10⁻⁶/°C across the design temperature range, alongside matching welding wire and cryogenic piping materials—all documented for the contractor’s design file.
This case summarizes the application requirements, materials supplied by DZX and delivery value. For case-specific technical data, please contact our engineering team.
| Item | Details |
|---|---|
| Client Profile | LNG tank contractor (membrane containment systems) |
| Project Scale | Tank construction project, volume membrane-strip supply |
| Application | Membrane containment, cryogenic piping and structural supports |
| Materials Supplied | Invar36, 316L stainless steel and welding wire |
| Supply Forms | Strip, plate and welding wire |
| Lead Time | Standard grades: 3-4 weeks; project batches scheduled to milestones |
| Project Country | Qatar |
| Project Year | 2024 |
Our Solution
The contractor’s design authority required three verifiable material properties:
- Verified low expansion: membrane strip had to remain within design CTE limits from ambient temperature to -162°C. Nominal claims without test data were rejected.
- Consistent strip geometry: membrane fabrication required uniform width and thickness with controlled flatness for laser welding.
- Weldability: matching welding wire needed verified chemistry for defect-free membrane welds.
DZX delivered thermal expansion as a verified material property:
Invar36 strip was supplied with batch dilatometer-measured CTE, typically ≤ 1.5 × 10⁻⁶/°C across the agreed temperature range. Width, thickness and flatness were verified for membrane fabrication. Matching welding wire had verified chemistry, while 316L stainless steel covered cryogenic piping. Every batch included CTE, dimensional and chemistry reports for the contractor’s design file.
| Material | Representative Grades | Key Properties | Available Forms |
|---|---|---|---|
| Expansion alloys | Invar36 | Low CTE and membrane containment | Strip and plate |
| Stainless steel | 316L | Cryogenic piping | Tube and fittings |
| Welding wire | Matching grades | Membrane and piping welds | Wire |
View Expansion Alloys → | View Stainless Steel Alloys → | View Welding Wire →
Membrane containment systems
Cryogenic piping and components
Matching cryogenic weld materials
Technical Specifications
Key technical parameters agreed before production. Contact us for grade-specific datasheets and tolerance-verification reports.
| Parameter | Agreed Specification | Verification Method |
|---|---|---|
| CTE (design temperature range) | ≤ 1.5 × 10⁻⁶/°C | Batch dilatometer measurement |
| Strip geometry | Width/thickness to drawing | Coil-by-coil dimensional report |
| Flatness | To membrane fabrication requirements | Surface plate + feeler gauge |
| Welding-wire chemistry | Matched to Invar36 chemistry | Batch chemical analysis |
| Service temperature | -162°C LNG service | CTE verified across the design range |
Each supplied batch includes a quality inspection certificate with chemical analysis, meeting the applicable standard for each grade.
| Material | Applicable Standards |
|---|---|
| Expansion alloys | GB/T 3308、ASTM F1684 |
| Stainless steel | ASTM A240、A312 |
| Welding wire | AWS A5.14 (nickel-based) |
| Quality System | Quality certificate including CTE and chemical analysis reports |
Delivery and Quality Support
- Fast delivery: Sample and production lead times follow the project schedule; standard grades and sizes can be dispatched promptly from stock.
- Quality traceability: Every batch includes material certificates and inspection reports, with full heat and batch traceability.
- Technical support: Responsive support covers pre-sale material selection, drawing review and post-sale processing advice.
- Ongoing service: Regular follow-up after delivery tracks performance and addresses feedback promptly.
Customer Feedback
- Design-authority acceptance: batch-measured CTE replaced nominal Invar claims
- Smooth membrane fabrication: uniform strip geometry and flatness supported laser welding
- Defect-free welds: matching welding-wire chemistry verified
- Complete design file: batch CTE, dimensional and chemistry reports
- Project-level supply: strip batches scheduled to tank-construction milestones
- Matching piping supply: 316L cryogenic piping under the same quality system
Our Capabilities
Jiangsu DZX Technology Co., Ltd. (Changzhou DLX Alloy) was founded in 2016. Its core team has worked in the field since 2002, with 24 years of precision-alloy R&D and production experience, operating a self-owned 12,000-square-meter modern factory with an ISO9001 system covering three inspection stages. Annual alloy output exceeds 1,200 tonnes, serving 1500+ business customers worldwide. The company operates integrated melting, drawing, annealing and precision-machining workshops, supporting volume customization of strip, wire, tube and bar. Every batch includes a chemical analysis report (MTC) for full delivery-quality traceability.
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