Duplex SS 2205 Pressure Safety Valves

Falcon Duplex SS 2205 Pressure Safety Valves

High Strength and Superior Resistance to Chloride Stress Cracking

Falcon’s Duplex 2205 safety valves are engineered for rugged industrial service where standard austenitic steels (like 316L) are at risk of localized corrosion. By utilizing a balanced 50/50 microstructure of austenite and ferrite, these valves provide nearly twice the yield strength of standard stainless steels, along with exceptional resistance to pitting and stress corrosion cracking.

Special Features of Falcon Duplex 2205

• Advanced PREN Rating: Boasting a Pitting Resistance Equivalent Number (PREN) of ≥35, Falcon Duplex 2205 offers superior protection in seawater and brackish water environments.

• Mechanical Efficiency: The high yield strength of Duplex 2205 allows for more robust valve designs capable of handling higher pressure cycles without material fatigue.

• Erosion-Corrosion Durability: The high surface hardness of the alloy makes these valves ideal for high-velocity discharge and applications involving abrasive slurry media.

• Sour Service Compatibility: Inherently resistant to sulfide stress cracking, making these valves suitable for $H_2S$ (Sour Gas) environments in oil and gas production.

Engineering & Design Standards

Falcon Duplex 2205 valves are designed and tested to meet the world’s most demanding engineering codes:

• Design Standard: Fully compliant with API 526, providing standardized dimensions and orifice sizes for global interchangeability.

• Construction Styles:

  • Conventional: Used for systems where backpressure is constant and low.

  • Balanced Bellows: Designed to neutralize variable backpressure and protect the spring and guiding surfaces from corrosive process fluids.

• Sizing & Calculations: All flow capacities are verified according to ASME Sec. VIII Div. 1 and API RP 520.

• Performance Verification: Every unit undergoes rigorous seat tightness and set-pressure testing as per API 527.

Material Grade Specification (Forged & Cast)

Falcon ensures full material traceability and structural integrity by utilizing the following Duplex 2205 specifications:

Component	Common Name	Forged Grade (ASTM/UNS)	Cast Grade (ASTM/UNS)
Valve Body / Bonnet	Duplex 2205	ASTM A182 F51 / F60	ASTM A890 Grade 4A (CD3MN)
Nozzle & Disc	Alloy 2205	ASTM A182 F51 (UNS S31803)	—
Bellows	Duplex / Inconel	ASTM A240 UNS S32205	—

Quality Assurance & Third-Party Inspection

To guarantee performance in high-pressure and corrosive environments, Falcon valves are available for witness testing and certification by:

• DNV (Det Norske Veritas)

• SGS

• TÜV

• Velosi

Primary Applications

Falcon Duplex 2205 pressure safety valves are specifically engineered for:

1. Oil & Gas: High-pressure separators, flowlines, and heat exchangers handling sour gas.

2. Desalination: Brine handling and Reverse Osmosis (RO) high-pressure pump protection.

3. Chemical Processing: Production of organic acids, chlorides, and chemical solvents.

4. Marine: Offshore fire-water systems and ballast water relief.

5. Pulp & Paper: Digester relief valves and bleaching plant components.

Technical Compliance Matrix

Category	Falcon Standard
Design Base	API 526
Capacity Sizing	ASME Sec. VIII Div. 1 / API RP 520
Leakage Testing	API 527
NACE Compliance	MR0175 / ISO 15156
Inspections	DNV, SGS, TUV, Velosi

Duplex SS 2205: Seawater & Marine Specialization

Seawater is a highly aggressive medium due to its high chloride content, which leads to pitting and Stress Corrosion Cracking (SCC) in standard stainless steels. Falcon Duplex 2205 is the engineered solution for these environments, offering a dual-phase microstructure that provides superior durability against marine-induced corrosion.

Pitting Resistance (PREN)

The most critical metric for seawater service is the Pitting Resistance Equivalent Number (PREN).

• Falcon Standard: Our Duplex 2205 maintains a PREN ≥ 35.
• Ferritic Phase Benefit
• Surface Hardness:Falcon Duplex 2205 ~31 HRC