DL/T 438-2023 in English
VALIDThe technical supervision codes for metal in fossil-fuel power plant
- Issued on:2023-10-11
- Implemented on:2024-04-11
- File Format:PDF
- Delivery:Via email within 5 business days
$582.00
Introduction
Background of Standard Revision and Technological Evolution
This revision is the fifth revision since the first release in 1983. The standard system has evolved through versions such as SD 107-1983 and DL 438-1991, reflecting the new requirements for metal supervision of new technologies such as ultra-supercritical units and deep peak regulation.
Comparison of core revisions
| Technical dimension | DL/T 438-2016 | DL/T 438-202X |
|---|---|---|
| Scope of supervision | Steel structure including pressure vessel | Delete pressure vessel, add generator bearing |
| Hardness control | No clear difference limit | Measurement value difference ≤20HB, deviation ≤5HB |
| P91/P92 steel | Uniform hardness requirements | Pipes 190-250HB, fittings 185-250HB |
Key technical innovations
Special supervision of deep peak-shaving units
The new Chapter 14 requires a low-cycle fatigue damage assessment of turbine rotors and boiler pressure-bearing components. A typical case shows that the crack rate of the main steam pipe of the peak-shaving unit is 40% higher than that of the base load unit.
Refined hardness control
Appendix B updates the hardness values of 28 kinds of metal materials, and specifically stipulates 9%-12%Cr steel parts:
- The hardness of blade steel is increased by 15-20HB
- The lower limit of hardness of header forgings is adjusted to 180HB
Implementation suggestions
- Transition period between the old and new standards: focus on the hardness classification control requirements of P91/P92 steel
- Update of testing terminology: "inspection" is uniformly changed to "testing", involving 6 methods such as ultrasonic and magnetic powder
- Life extension assessment: refer to Appendix C for damage classification of components with a running time of more than 200,000 hours
Loading PDF document...
Error loading PDF. Please make sure the file is valid and try again.
We also recommend
-
DL/T 790.12-2001 in English
Distribution Automation Using Distribution Line Carrier Part 1: General Provisions Part 2: Guidelines for Formulation of Specifications
2001-12-26 -
DL/T 5598-2021 in English
Regulation for content and depth of preliminary design for submarine power cable
2021-01-07 -
DL/T 5800-2019 in English
Specification of rapidly hardening concrete construction for road in hydropower and water conservancy project
2019-11-04 -
DL/T 646-1998 in English
Technical specification of manufacturing steel transmission pole structures
1998-03-19
