what is ASTM A182 Flange Specification？

In this article, we'll break down the ASTM A182 flange specification, covering its material grades, mechanical properties, pressure classes, and key comparisons with other standards like ASTM A240 and A105.

 

ASTM A182 flange specification.pdf

 

What Is ASTM A182?

ASTM A182 is a specification issued by ASTM International that covers forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valves used in high-temperature service applications.

 

Common Grades of ASTM A182 Stainless Steel Flanges

Grade	UNS Number
F304	S30400
F304L	S30403
F316	S31600
F316L	S31603
F321	S32100
F347	S34700

 

Chemical Composition (Example: ASTM A182 F316L)

Element	Composition (%)
C	≤ 0.03
Mn	≤ 2.00
P	≤ 0.045
S	≤ 0.030
Si	≤ 1.00
Cr	16.0–18.0
Ni	10.0–14.0
Mo	2.0–3.0
Fe	Balance

Mechanical Properties of ASTM A182 Flanges (Example: F316L)

Property	Minimum Value
Tensile Strength	485 MPa (70 ksi)
Yield Strength (0.2%)	170 MPa (25 ksi)
Elongation	≥ 30%
Hardness (Brinell)	≤ 217 HBW

 

Types of ASTM A182 Flanges

Weld Neck Flange (WN)

Slip-On Flange (SO)

Blind Flange (BL)

Socket Weld Flange (SW)

Threaded Flange (TH)

Lap Joint Flange (LJ)

 

ASTM A182 flanges ANSI pressure classes:

Pressure Class	Typical Use Case
Class 150	Low-pressure piping
Class 300	General-purpose pipelines
Class 600–2500	High-pressure, high-temperature pipelines

The pressure-temperature chart for each flange class is specified in ASME B16.5.

 

Applications of ASTM A182 Flanges

Due to their corrosion resistance and strength, ASTM A182 stainless steel flanges are widely used in:

Petrochemical plants

Offshore oil rigs

Power stations (steam & nuclear)

Pharmaceutical manufacturing

Food and beverage processing

 

ASTM A182 vs ASTM A240: What's the Difference?

ASTM A182 and A240 are both stainless steel standards, but they differ in product form and application: A182 covers forged or rolled components (flanges, fittings, valves) for high-temperature service, while A240 covers plate, sheet, or strip for pressure vessels. A182 is forged/machined, whereas A240 is used for fabrication from plate.

Aspect	ASTM A182	ASTM A240
Product Form	Forged flanges, fittings, valves	Plate, sheet, strip
Application	High-temp pressure components	Flat products for fabrication
Typical Grades	F304, F316, F321	TP304, TP316, TP321

Summary: Use ASTM A182 for forged components, and ASTM A240 for flat-rolled stainless steel.

 

ASTM A182 Flange Price (2024–2025 Reference)

Flange Type	Material	Size (inches)	Approx. Price (USD)
Weld Neck	F316L	4" Class 150	$35–$50 each
Blind	F304	6" Class 300	$60–$85 each
Slip-On	F316	8" Class 150	$90–$120 each