ASTM A182 F53 (UNS S32750) flanges are an excellent choice for desalination plants, particularly in seawater handling and high-chloride environments.ASTM A182 Grade F53, also known as UNS S32750 or Alloy 2507, is a super duplex stainless steel renowned for its exceptional strength and outstanding corrosion resistance, particularly in chloride-rich environments like seawater, brine, and chemical processing.
Equivalent grade of ASTM A182 F53
F53 (ASTM grade designation)
UNS S32750 (Unified Numbering System)
Alloy 2507 (Commercial name by Sandvik and others)
1.4410 (EN/DIN designation)
Why A182 F53 ?
Key Characteristics:
Property
Description
PREN > 40
Excellent pitting resistance in chloride environments
High strength
Yield strength ~2× higher than 316L
Cr + Mo + N + Ni
Synergistic alloying for strong corrosion and SSC resistance
Low thermal expansion
Good for heat exchangers and desalination systems
Excellent weldability
Can be fabricated with proper procedure (heat input control)
ASTM A182 F53 Chemical Compostion
Chemical Composition Limits
Weight%
C
Mn
P
S
Si
Cr
Ni
Mo
N
Cu
Super Duplex F53
0.03 max
1.2 max
0.035 max
0.015 max
0.8 max
24-26
6-8
3-5
0.3
0.5 max
ASTM A182 F53 heat treatment requirement
Grade
Heat Treat Type
Austenitizing/Solutioning Temperature, min °F (°C)<sup>A</sup>
Cooling Media
Quenching Cool Below °F (°C)
Tempering Temperature min °F (°C)
F 53
solution treat and quench
1880 [1025]
liquid
500 [260]
—
ASTM A182 F53 Tensile Test and Hardness requirement
Grade Symbol
Tensile Strength, min, ksi [MPa]
Yield Strength, min, ksi [MPa]<sup>^</sup>
Elongation in 2 in. [50 mm] or 4D, min, %
Reduction of Area, min, %
Brinell Hardness Number
F 53
116 [800]
80 [550]
15
–
310 max
A182 F53 Super Duplex Flange Specification
Material: ASTM A182 Grade F53 UNS Number: S32750 Common Type: Weld Neck, Slip-On, Blind, Lap Joint Flanges Standards: ASME B16.5 / B16.47 / EN 1092-1
Dimensions and Standards
Feature
Specification
Size Range
½” to 60” (DN15–DN1500)
Pressure Class
150#, 300#, 600#, 900#, 1500#, 2500#
Standard Compliance
ASME B16.5, B16.47, MSS SP-44, EN 1092-1
Facing Options
RF (Raised Face), RTJ (Ring Type Joint), FF (Flat Face)
Tolerances
As per ASME B16.5 / EN 1092-1
Typical ITP inspection and test plan for ASTM A182 F53 flanges
No
Activity / Description
Reference Standard
Inspection Type
Acceptance Criteria
Document Required
1
Material Inspection
ASTM A182, EN 10204
Visual / MTC Review
Chemical & Mechanical as per ASTM A182 GR. F53
Mill Test Certificate
2
Forging Process
In-house Standard
In-process
As per drawing & process control
3
Heat Treatment (if required)
Internal / ASTM A991
Review / Witness
As per WPS / PQR
HT Record
4
Machining
ASME B16.5 / Drawing
In-process
ASME B16.5 / Drawing
5
Chemical Test
ASTM A182
Review / Witness
ASTM A182 F53
Chemical Test Report
6
Machanical Test
ASTM A370
Review / Witness
ASTM A182 F53
Machanical Test Report
7
Dimensional Inspection
ASME B16.5 / Drawing
Measurement
Tolerance per standard
Dimensional Report
8
NDT – UT / PT (if applicable)
ASME Sec V / Client Spec
Witness / Review
ASME
NDT Reports
9
Marking & Stamping
ASTM A182 / Project Spec
Visual
As per code
Marking Photo
10
Packing & Preservation
Internal Procedure
Visual
Export-worthy packaging, corrosion protection
Packing List / Photos
11
MTC
EN10204 3.1 /3.2
Final
All docs submitted & approved
Order Specification for ASTM A182 F53 Weld Neck Flanges
1. Product: Weld Neck Flanges 2. Material Grade: ASTM A182 F53 (UNS S32750, Super Duplex Stainless Steel) 3. Flange Type: Weld Neck (WN) 4. Design Standard: ASME B16.5 (for sizes ≤ 24″) or ASME B16.47 (for sizes > 24″) 5. Pressure Rating: [Class 150 / 300 / 600 / 900 / 1500 / 2500] (specify as required) 6. Size Range: [e.g., 2″ NB to 24″ NB] 7. Face Type: Raised Face (RF) / Ring Type Joint (RTJ) / Flat Face (FF) 8. Facing Finish: 125–250 AARH serrated finish (default)
