Brazed Plate Heat Exchanger
1Key Takeaways
The NB/T 47045-2024 standard, titled "Brazed Plate Heat Exchangers," is a technical specification issued by the Chinese energy industry, effective from November 24, 2024. This standard provides comprehensive guidelines for the design, manufacturing, testing, and inspection of brazed plate heat exchangers, which are wi…
2Expert Interpretation
This article comprehensively interprets the latest industry standard NB/T 47045-2024 brazed plate heat exchangers, covering key technical requirements such as material selection, design verification, manufacturing process, inspection and testing, and compares the main technical changes of the 2015 version of the standard, providing professional implementation suggestions and engineering application guidance.
Background of Standard Revision and Technological Evolution
As an important technical specification in the field of brazed plate heat exchangers, NB/T 47045-2024 has undergone 9 major technical updates compared to the 2015 version. This revision focuses on strengthening:
| Technical Dimensions | 2015 Edition | New Contents of the 2024 Edition |
|---|---|---|
| Test Methods | Explosion Test | Add Temperature Alternation/Vibration/Salt Spray/Internal Corrosion Tests |
| Material Standards | 7 Types of Main Materials | Expanded Brazing Filler Metals and Stainless Steel Grades |
| Cleanliness Control | No Specific Requirements | Clear Residue Index (Solid ≤50mg/m²) |
Analysis of Key Technical Requirements
1. Material Specifications
The standard stipulates that plates are mainly made of stainless steel such as S30408/S31603, and nickel-based alloys are newly added as brazing filler metals. Critical Control Points:
- Material Certification Document Traceability ≥ 7 Years
- Plate Thinning ≤ 25% of Actual Thickness
- Corrugation Depth Tolerance ±0.03mm (Area ≤ 0.2m²)
2. Design Verification System
Burst Test Requirements Improvement:
| Verification Method | Pressure Multiples | Number of Cycles |
| Pure Burst | ≥4 Times of Design Pressure | - |
| Fatigue + Burst | ≥3 Times of Design Pressure | 5500 Times |
Key points of manufacturing and inspection
1. Process control
The brazing process must:
- Save the complete process curve (temperature/pressure)
- Vacuum brazing furnace operation
- Rework times ≤1
2. Upgrade of inspection standards
Three new key tests:
| Test type | Qualified index | Reference standard |
| Salt spray test | No substrate corrosion | GB/T 10125 |
| Temperature alternation | 10 cycles (-40~120℃) | Clause 8.7 |
| Leakage rate | ≤1.3×10⁻⁶Pa·m³/s | Nitrogen mass spectrometry detection |
Project implementation suggestions
1. Selection considerations
Select the plate material combination according to the medium characteristics:
- Chloride ion environment: S31603 is preferred
- Low temperature working conditions: The low temperature toughness of the solder needs to be verified
2. Installation specifications
Critical load limit (taking M12 stud as an example):
- Maximum axial force: 6000N
- Allow torque: 33Nm
- Buffer devices need to be installed in vibration situations