Duplex Stainless Steel Butterfly Valve DN65 Price – Specialized for Seawater Desalination
The Duplex Stainless Steel Butterfly Valve DN65 has become a widely specified solution for desalination plants, offshore platforms, and coastal power generation facilities. Its unique combination of high strength and exceptional resistance to chloride-induced corrosion makes it the preferred choice for seawater handling applications. This article provides a comprehensive 2026 price reference and outlines the essential selection parameters for this specialized valve.The main Butterfly Valve product names of China Butterfly Valve Network include:Accumulator(Emergency Off) Quick Off Butterfly Valve,Anti-sediment Butterfly Valve,Anti-condensation Al-alloy Diecasting Butterfly Valve,Butterfly Buffering Check ValveButt Welded Hard-sealed Butterfly Valve,Electric Metal Hard-sealed Wafer Butterfly Valve,Electric Hard-sealed Flange Butterfly Valve,Electric Soft-sealed Wafer Butterfly Valve,Electric Single Eccentric Wafer Butterfly Valve,Electric Soft-sealed Flange Butterfly Valve.
2026 Price Reference for Duplex Stainless Steel Butterfly Valve DN65
As of 2026, the price for a Duplex Stainless Steel Butterfly Valve DN65 varies significantly based on the specific duplex grade, design complexity, and actuation type. For a 2507 super duplex stainless steel hard-sealed butterfly valve in DN65 size, a typical manufacturer reference price is approximately ¥3,100 per unit . This price reflects the premium material costs associated with super duplex alloys, which contain high levels of chromium, molybdenum, and nitrogen to achieve superior corrosion resistance .
For 2205 duplex stainless steel models, which are more economical than 2507, prices are generally lower while still providing excellent corrosion resistance for many seawater applications. The final transaction cost depends on several factors including sealing material (PTFE or metal seat), connection type (wafer or lug), pressure rating, and order quantity .
It is important to note that while standard stainless steels like 304 or 316 are significantly cheaper, they are unsuitable for seawater service due to rapid pitting and crevice corrosion. Duplex stainless steel represents the minimum acceptable material grade for reliable desalination and seawater applications .
Key Factors Influencing the Price of DN65 Duplex Stainless Steel Butterfly Valves
Understanding what drives the cost of a duplex stainless steel butterfly valve is essential for making an informed procurement decision.
Alloy Grade – 2205 vs. 2507
The choice between standard duplex (2205) and super duplex (2507) is the most significant cost factor. 2205 duplex stainless steel (PREN ≈ 35) offers excellent resistance to chloride stress corrosion cracking and is suitable for seawater desalination pretreatment and moderate chloride environments . 2507 super duplex stainless steel (PREN > 40) commands a premium of roughly 1.5 to 2 times the cost of 2205, but delivers superior resistance to pitting and crevice corrosion in high-temperature and high-chloride conditions . For seawater with chloride concentrations around 19,000 ppm, super duplex is strongly recommended to ensure long service life .
Sealing Type – Soft Seal vs. Hard Seal
PTFE-lined or PTFE-seated** valves offer excellent chemical inertness and bubble-tight shutoff, making them the most common choice for desalination applications. PTFE provides outstanding resistance to seawater and minimizes friction during operation. Hard-sealed (metal-to-metal)**designs are required for higher temperatures (above 150°C) or abrasive conditions, but they typically come at a premium due to more complex manufacturing processes .
Duplex stainless steel offers several advantages specifically suited for desalination:
Superior chloride resistance – The high chromium and molybdenum content provides exceptional resistance to pitting and crevice corrosion, the primary failure modes in seawater service .
High mechanical strength – Duplex alloys offer approximately twice the yield strength of standard austenitic stainless steels, allowing for thinner valve bodies and reduced weight .
Excellent stress corrosion cracking resistance*– The dual-phase microstructure (austenite and ferrite) provides superior resistance to chloride stress corrosion cracking, a common problem in 316 stainless steel exposed to seawater .
Long service life – Field experience and research have demonstrated that duplex stainless steel significantly outperforms alternatives like aluminum bronze in seawater applications, providing extended operational reliability .
Key Selection Parameters for DN65 Duplex Stainless Steel Butterfly Valves
When specifying a duplex stainless steel butterfly valve DN65 for seawater desalination, several technical parameters must be carefully defined.
The Duplex Stainless Steel Butterfly Valve DN65 is the specialized solution for seawater desalination, offering the critical combination of high strength and exceptional chloride corrosion resistance required in this demanding application. As of 2026, prices for a 2507 super duplex hard-sealed model in DN65 size start at approximately ¥3,100, with 2205 models available at lower costs . The final price is determined by the duplex grade (2205 vs. 2507), sealing type (PTFE vs. metal), design complexity, and order quantity.
When selecting this valve, pay careful attention to the material grade and PREN value, temperature and pressure ratings, sealing material compatibility, and connection type. For the most competitive and accurate pricing, contact manufacturers directly with your complete technical specifications and request material test certificates to guarantee product quality. Investing in the correct duplex stainless steel butterfly valve is essential for ensuring long-term reliability and minimizing maintenance costs in seawater desalination systems.
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