904L Weld Neck Flanges Order

On March 28, 2025, we received an inquiry from a long-term domestic client regarding ASME B16.5 904L weld neck flanges. Drawing on years of experience, we promptly provided a quotation. Trusting our capabilities, the client placed an order on the same day.

Upon receiving the order, our sales representative immediately coordinated with procurement to confirm details including flange type, material grade, pressure rating, thickness, standards, and flange face specifications.

Procurement List Information

Flange Type: Weld Neck Flange                                                Material Grade: ASTM A182 F904L

Nominal Diameter: DN50 & DN200                                         Wall Thickness Schedule: Sch 10S

Pressure Rating: Class 150                                                        Production Standard: ASME B16.5

Manufacturing Process: Forged                                                 Quantity: 10 Pieces

Inspection photos

About Stainless Steel 904L Flanges

Stainless steel 904L is a super-austenitic alloy known for its exceptional corrosion resistance. It performs well in harsh environments, such as those containing sulfuric acid, phosphoric acid, and chlorides. The 904L weld neck flanges are widely used in chemical processing, offshore oil and gas, and pollution control systems due to its durability and reliability.

Specification of Weld Neck Flanges

Material Standards	ASTM A182 , ASTM A105 , ASTM A350 , ASTM A694, etc.
Dimension Standard	ASME B16.5, B 16.47 Series A & B, BS4504, BS 10, EN-1092, DIN, etc.
Standard	ASME Flanges, BS Flanges, DIN Flanges, EN Flanges, etc.
Class / Pressure	150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc.
Flange Face Type	Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ), etc.
DIN Flanges	DIN 2527, 2566, 2573, 2576, 2641,2642, 2655, 2656, 2627, 2628, 2629, 2631, 2632, 2633, 2634, 2635, 2636, 2637,2638, 2673.
JIS Flanges	JIS B2220 5K, JIS B2220 10K, JIS B2220 16K, JIS B2220 20K
BS Flanges	BS4504 PN 6, BS 4504 PN 10, BS4504 PN 16, BS4504 PN 25, BS4504 PN 40, BS 4504 PN 64, BS 4504 PN 100, BS 4504 PN 160, BS 4504 PN 250, BS 10, BS Table D, BS Table E, BS Table F, BS Table H.

ASTM A182 F904L Material

ASTM A182 F904L is a premium material grade specifically designed for corrosive applications. Its composition and mechanical properties make it ideal for manufacturing high-performance 904L weld neck flanges products.

Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Ni	Cr	Mo	N	Ti	Cu
ASTM A182 F904L  (N08904)	MIN						23.00	19.00	4.00			1.00
	MAX	0.02	2.00	0.040	0.030	1.00	28.00	23.00	5.00	0.10		2.00

Mechanical Properties

MATERIAL	T.S (MPA)	Y.S (MPA)	EL %
ASTM A182 F904L	490 min	215 min	35 min

ASME B16.5 Standard

ASME B16.5 is a widely used standard developed by the American Society of Mechanical Engineers. It specifies the dimensions, tolerances, materials, pressure ratings, marking, and testing methods for pipe flanges and flanged fittings used in piping systems.

Scope of ASME B16.5

The standard applies to pipe flanges and flanged fittings with nominal pipe sizes (NPS) from ½ inch to 24 inches, and pressure classes from 150 to 2500.

Flange Types Covered

ASME B16.5 covers several types of flanges, including Weld Neck, Slip On, Socket Weld, Threaded, Lap Joint, and Blind flanges.

Class 150 WN Flange Dimension

Nominal Pipe Size		A	B	C	D	E	F	G	H	I	J
inch	mm	mm	mm	mm	mm	mm	mm	mm	Holes	mm	mm
1/2	21.30	88.90	15.70	11.20	47.80	21.30	30.20	35.00	4	15.70	60.45
3/4	26.70	98.60	20.80	12.70	52.30	26.70	38.10	42.90	4	15.70	69.85
1	33.40	108.0	26.70	14.20	55.60	33.50	49.30	50.80	4	15.70	79.25
11/4	42.20	117.3	35.10	15.70	57.15	42.20	58.70	63.50	4	15.70	88.90
11/2	48.30	127.0	40.90	17.50	62.00	48.30	65.00	73.15	4	15.70	98.60
2	60.30	152.4	52.60	19.10	63.50	60.45	77.70	91.90	4	19.10	120.7
21/2	73.00	177.8	62.70	22.40	69.85	73. 15	90.4	104.6	4	19.10	139.7
3	88.90	190.5	78.00	23.90	69.85	88.90	108.0	127.0	4	19.10	152.4
31/2	101.6	215.9	90.20	23.90	71.40	101.6	122.2	139.7	8	19.10	177.8
4	114.3	228.6	102.40	23.90	76.20	114.3	134.9	157.2	8	19.10	190.5
5	141.3	254.0	128.3	23.90	88.90	141.2	163.6	185.7	8	22.40	215.9
6	168.3	279.4	154.2	25.40	88.90	168.4	192.0	215.9	8	22.40	241.3
8	219.1	342.9	202.7	28.40	101.6	219.2	246.1	269.7	8	22.40	298.5
10	273.0	406.4	254.5	30.20	101.6	273.0	304.8	323.8	12	25.40	362.0
12	323.8	482.6	304.8	31.75	114.3	323.8	365.3	381.0	12	25.40	431.8
14	355.6	533.4	To be specified by the Purchaser	35.10	127.0	355.6	400.1	412.7	12	28.40	476.3
16	406.4	596.9		36.60	127.0	406.4	475.2	469.9	16	28.40	539.8
18	457.2	635.0		39.60	139.7	457.2	505.0	533.4	16	31.75	577.9
20	508.0	698.5		42.90	144.5	508.0	558.8	584.2	20	31.75	635.0
24	609.6	812.8		47.80	152.4	609.6	663.4	692.1	20	35.10	749.3

Class 300 Weld Neck Flange Dimension

Class 400 Weld Neck Flange Dimension

Class 600 Weld Neck Flange Dimension

Class 900 Weld Neck Flange Dimension

Class 1500 Weld Neck Flange Dimension

Class 2500 Weld Neck Flange Dimension

Flange Faces

• Raised face flange (RF)
• Flat Face Flange (FF)
• Ring Joint Flange (RTJ)
• Male and Female Flange (M&F)
• Tongue-and-Groove Flange (T&G)

Frequently Asked Questions

Difference Between 904L and 316L

Durability

904L contains more chromium than 316L, forming a stronger protective layer for longer service life in seawater.

Corrosion Resistance

904L exhibits a higher PREN value (approximately 36 for 904L versus approximately 26 for 316L), demonstrating superior resistance to chloride, biofilm, and other corrosion mechanisms in seawater environments.

Steel Hardness

Both alloys have similar hardness, but 904L’s enhanced corrosion resistance makes it more reliable for marine filters.

Cost

The cost of 904L is significantly higher than that of 316L, but it offers a longer service life and requires less maintenance, making it more cost-effective in the long run.