Second, submit a written application report and basic unit status report;
3. Fill in the "Application Form for Professional Construction (Design) Qualification Certificate for Lightning Protection Projects" and apply for four copies.
4. The local lightning protection and disaster reduction authority decides whether to accept its application within ten days from the date of receiving the application. For those who do not have the basic conditions for application, the reasons should be returned.
V. Those who meet the requirements for application shall be submitted to the provincial lightning protection and disaster reduction authority. The provincial department for mine prevention and disaster reduction shall organize the preliminary review and sign the opinions. If the preliminary examination is qualified, it shall be reported to the competent meteorological department under the State Council within 20 days. If it is not qualified, it shall be returned to the original entity.
6. The competent meteorological department under the State Council shall organize the assessment of qualifications and approve the issuance of qualification certificates. If the assessment fails, submit the handling opinion within 30 days after the review
DUPLEX STAINLESS STEEL
Duplex Stainless Steels Available
Yuhong Group supplies LDX2101, 2205, Ferralium 255, Zeron 100 and LDX2507 in the form of plate, sheet, strip, bar, pipe, tubing, pipe fittings, flanges and weld wire.
Duplex Stainless Steel Overview
Duplex Stainless Steels, also referred to as austenitic-ferritic stainless steels, are a family of grades with about equal proportions of ferrite and austenite. These steels have a duplex microstructure which contributes to their high strength and high resistance to stress corrosion cracking. Due to their high content of chromium, nitrogen and molybdenum, duplex steels offer good resistance to local and uniform corrosion. Duplex stainless steels have good weldability.
Today, modern duplex stainless steels can be divided into three groups:
Lean Duplex such as LDX2101
Standard Duplex such as 2205, the work-horse grade accounting for more than 80% of duplex usage
Super Duplex such as Ferralium 255 and Zeron 100 and LDX2507
Of the duplex grades, duplex 2205 is the most widely used. However, the super duplex steels like Zeron® 100 and LDX2507 are excellent for servicing severe corrosive environments, such as offshore and marine applications. Lean duplex 2101 is available as an economic alternative to 300 series stainless steels.
What are the Characteristics of Duplex Stainless Steels ?
Very good resistance to uniform corrosion
Very good resistance to pitting and crevice corrosion
High resistance to stress corrosion cracking and corrosion fatigue
High mechanical strength
Good sulfide stress corrosion resistance
Good abrasion and erosion resistance
Good fatigue resistance high energy absorption
Low thermal expansion
Good weldability
In what Applications are Duplex Stainless Steels® used ?
Oil and gas equipment
Offshore technology
Seawater desalination plants
Chemical industry, especially when handling chlorides
Flue-gas cleaning
Desalination plants and seawater systems
Pulp and paper industry
Cargo tanks and pipe systems in chemical tankers
Firewalls and blast walls on offshore platforms
Bridges
Storage tanks
Pressure vessels, reactor tanks, and heat exchangers
Rotors, impellers and shafts
Duplex Boiler Tube,Duplex Seamless Boiler Tube,Duplex Steel Boiler Tube
YUHONG GROUP CO.,LIMITED , https://www.alloypipeline.com