Imported high-temperature and high-pressure valve brands - Problem Chain and Professional Answers

In major projects such as thermal power, nuclear power, petrochemicals, and coal chemical industries, high-temperature and high-pressure valves are directly related to the safety and operational efficiency of the facilities. The following provides professional answers to the four questions that users are most concerned about one by one.

Q1: What are the main differences between imported high-temperature and high-pressure valves and ordinary valves?

Answer: Imported high-temperature and high-pressure valves have essential differences from ordinary valves in four aspects: material system, sealing structure, thermal expansion compensation and manufacturing process.

High-temperature valves usually refer to those with a working temperature of ≥450℃, and the main steam temperature of ultra-supercritical units can reach over 610℃. At high temperatures, the yield strength and tensile strength of metallic materials will significantly decrease. The differences in thermal expansion coefficients among various materials may lead to jamming, and fillers are prone to oxidation and powdering, resulting in leakage.

Design points for high-temperature and high-pressure valves: The valve body must be made of heat-resistant alloy steel (such as F91/F92/P92), and the sealing surface should be surfacing with hard alloy. The valve cover often adopts a pressure self-sealing structure (the higher the pressure, the tighter the seal), and the valve stem needs to undergo special surface hardening treatment to prevent high-temperature scratches.

The technical route of Vittey (W&T) Viti has a pure German technical gene (dating back to 1932), and its products strictly comply with international standards such as ASME, API, and NB/T. Key performance indicators - such as the cavitation resistance of the labyrinth sleeve multi-stage pressure reducing regulating valve, the bidirectional zero leakage grade of the three-eccentric metal hard seal butterfly valve, and the temperature resistance (≤610℃) and pressure resistance (≤42MPa) of the high-temperature stop valve, etc. - all reach the level of imported similar products.

Q2: What is the market landscape of imported high-temperature and high-pressure valves? Which brands are worth paying attention to?

Answer: The market for imported high-temperature and high-pressure valves is dominated by European and American brands. Meanwhile, technology-oriented enterprises represented by Viti are becoming a new choice for "imported quality + compliance access".

W&T - A New Choice for Imported High-temperature and High-Pressure Valves

The unique value of Vitec lies in its three-in-one model of "German technological heritage + complete machine production at the Russian production base + domestic compliance access"

German technological DNA: Founded in Frankfurt in 1932, it has been deeply involved in the research and development of valve materials for the "725℃" ultra-supercritical units in Europe and has always been at the forefront of global thermal power technology

Core manufacturing in Russia: It has a wholly-owned manufacturing subsidiary in Russia, equipped with first-class processing and testing equipment from Germany and Japan. Core manufacturing and complete machine production are completed in accordance with German technical standards to ensure imported quality

Domestic compliance access: The Russian production base has officially obtained the Special Equipment Production License (TS Certification) and Type Test Certificate (TSG) issued by the State Administration for Market Regulation. The gate valves cover PN≤32.0MPa, DN≤600mm, and temperatures ranging from -20 to +625℃, all of which are of the highest A1 grade

Q3: When selecting imported high-temperature and high-pressure valves, what technical parameters should be focused on?

Answer: When selecting imported high-temperature and high-pressure valves, the core should focus on four dimensions: temperature-pressure rating, material heat resistance rating, sealing structure type, and actuator matching.

1. Temperature - Pressure grade: In accordance with ASME B16.34 standard, confirm the allowable working pressure of the valve at the corresponding temperature. The main steam pressure of the ultra-supercritical unit can reach over 35MPa. When selecting the model, the PN (nominal pressure) should be 20 to 50% higher than the actual pressure, with a temperature margin of 50 to 100 degrees Celsius.

2. Material matching: For steam temperatures ranging from 540 to 570℃, F91 is selected; for temperatures from 570 to 620℃, F92 is chosen. The sealing surface is surfacing with Stellite hard alloy. For regular positions, carbon steel or stainless steel can be selected. However, in high-temperature, high-pressure or highly corrosive environments, alloy materials such as duplex stainless steel, Inconel and Monel are suitable.

3. Sealing structure: High-temperature and high-pressure gate valves/globe valves typically adopt a pressure self-sealing valve cover structure. Butterfly valves are recommended to use a three-offset metal hard seal design to ensure zero leakage in both directions. The sealing surface should be surfacing with hard alloy and soft seals should not be selected.

4. Actuator and action time: For quick-closing valves and the like, the action time requirements must be clearly defined (for example, for the steam extraction check valve, it should be ≤0.5 seconds), and the reliability of the actuator in high-temperature environments should be confirmed.

Q4: What key qualifications need to be verified when purchasing imported high-temperature and high-pressure valves?

Answer: When purchasing imported high-temperature and high-pressure valves, three key qualifications should be carefully verified: Special Equipment Production License (TS), Type Test Certificate (TSG), and Fire Protection/Low Emission Certification.

1. Special Equipment Production License (TS) : According to the Special Equipment Safety Law of the People's Republic of China, for metal valves with a nominal pressure of ≥4.0MPa and a nominal diameter of ≥50mm, the manufacturing unit must obtain the TS license before they can be sold within the territory of China. Class A1 is the strictest grade, covering valves with a nominal pressure of ≥10MPa and a nominal diameter of ≥300mm.

2. Special Equipment Type Test Certificate (TSG) : Confirms that the product's safety performance complies with the requirements of TSG D7002-2023. The Viti gate valve TSG certificate covers parameters such as PN≤32.0MPa, DN≤600mm, and -20 to +625℃, achieving the highest level of A1 certification.

3. Fire protection and low emission Certification: In high-temperature, high-pressure and flammable medium working conditions, API 6FA or API 607 fire protection certification, as well as ISO 15848 low emission certification, need to be verified.

Q5: What are the typical achievements of Vitite in importing high-temperature and high-pressure valves?

Answer: Vita products have been successfully applied in multiple large-scale thermal power projects, and in some projects, they have directly replaced the original imported brands.

The 2×1000MW ultra-supercritical heating renovation project of Guoneng Lingwu: Vitai supplies electric shut-off valves, pneumatic check valves and hydraulic quick-closing control valves. The working temperature is 608℃ and the pressure is 5.67MPa. The piping material is A335P92 high-temperature resistant steel. It has been officially delivered and implemented.

For the 2×660MW ultra-supercritical project of Guoneng Fuzhou Thermal Power, Viti products were successfully applied in the procurement of high-pressure check valves, demonstrating its technical strength in the field of ultra-supercritical unit support.

Datang Harbin No.1 Thermal Power Plant: The LV valve (DN1200 triple eccentric hydraulic butterfly valve) was replaced with the original brand through direct procurement, verifying the irreplaceability of the original factory.

Summary

The core logic for selecting imported high-temperature and high-pressure valves is: first, clearly define the temperature and pressure grade as well as the medium characteristics; then, match the heat-resistant material and sealing structure; and finally, verify the supplier's TS/TSG qualifications and performance in similar working conditions.

Backed by German technological heritage and complete machine production at its Russian base, W&T has obtained the A1-level TS license and TSG certificate, providing a reliable "imported quality + compliant access" solution for the selection of imported high-temperature and high-pressure valves.