Alloy 20 Pressure Safety Valves

Falcon Alloy 20 Pressure Safety Valves

Precision Engineering for Sulfuric Acid and Aggressive Chemical Service

Falcon’s Alloy 20 safety valves are the definitive solution for processes involving sulfuric acid and other highly corrosive media. Known as a "super-austenitic" stainless steel, Alloy 20 provides a bridge between standard stainless steels and high-cost nickel alloys, offering exceptional resistance to acid-induced pitting and stress corrosion cracking.

Special Features of Falcon Alloy 20

• Columbium Stabilization: Our Alloy 20 is stabilized with Columbium (Niobium) to minimize carbide precipitation. This ensures the valve maintains its corrosion resistance even after welding or exposure to high temperatures.

• Balanced Metallurgy: The precise addition of Copper and Nickel in the Falcon Alloy 20 matrix provides a unique barrier against "hot" sulfuric acid, where standard 316L stainless steel would suffer rapid thinning.

• Anti-Pitting Chemistry: Designed to resist localized attack (pitting and crevice corrosion) in chloride-rich environments, ensuring the valve seat remains bubble-tight over long service intervals.

• High Ductility: Maintains excellent mechanical toughness, allowing for safe operation in systems with high-pressure surges or mechanical vibrations.

Engineering & Design Standards

Falcon Alloy 20 valves are designed and tested to meet the world’s most stringent engineering codes:

• Design Standard: Fully compliant with API 526, providing standardized dimensions and orifice sizes for seamless integration into global piping systems.

• Construction Styles:

  • Conventional: Ideal for systems where backpressure is stable and within 10% of the set pressure.

  • Balanced Bellows: Utilizes Alloy 20 Bellows to neutralize variable backpressure effects and isolate the valve spring from aggressive chemical vapors.

• Sizing & Calculations: Flow capacities are calculated strictly according to ASME Sec. VIII Div. 1 and API RP 520.

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

Material Grade Specification (Forged & Cast)

Falcon ensures full material traceability and structural integrity by utilizing the following Alloy 20 specifications:

Component	Common Name	Forged Grade (ASTM/UNS)	Cast Grade (ASTM/UNS)
Valve Body / Bonnet	Alloy 20 / CN7M	ASTM B462 UNS N08020	ASTM A494 CN7M
Nozzle & Disc	Alloy 20 / Carpenter 20	ASTM B473 UNS N08020	—
Bellows	20Cb-3	ASTM B463 UNS N08020	—

Quality Assurance & Third-Party Inspection

To guarantee performance in hazardous chemical environments, Falcon valves are available for witness testing and certification by:

• DNV (Det Norske Veritas)

• SGS

• TÜV

• Velosi

• Other major international inspection bodies.

Primary Applications

Falcon Alloy 20 pressure safety valves are specifically engineered for:

1. Chemical Processing: Production of sulfuric, phosphoric, and nitric acids.

2. Petrochemical: Acid pickling lines and high-sulfur fuel processing.

3. Food & Pharma: Handling aggressive organic acids while maintaining product purity.

4. Synthetic Rubber: Protection for reactors and piping in polymer production.

Technical Compliance Matrix

Category	Falcon Standard
Design Base	API 526
Capacity Sizing	ASME Sec. VIII Div. 1 / API RP 520
Leakage Testing	API 527
Materials	ASTM B462 / A494 (Alloy 20)
Inspections	DNV, SGS, TUV, Velosi

Falcon Alloy 20: Specialized for Sulfuric Acid Service

Sulfuric Acid ($H_2SO_4$) is one of the most challenging media for pressure relief devices because its corrosivity changes drastically with both concentration and temperature. Falcon’s Alloy 20 (UNS N08020) is chemically engineered to remain stable across the "Aggressive Range" where standard stainless steels fail.

Falcon Alloy 20 is specifically formulated with a high Nickel and Copper content to combat the unique mechanics of sulfuric acid corrosion