SS 304 Series Flanges for General Purpose Piping

KVN SS 304/304L/304H Flanges are precision-engineered pipe connection components designed for reliable performance in critical industrial systems. These flanges are available in a variety of face types, pressure ratings, and dimensions to suit diverse operating requirements. Manufactured from high-grade stainless steel, they are developed in accordance with international standards and are available in slip-on, blind, weld neck, threaded, socket weld, and ring-type joint configurations. These flanges are engineered to deliver a secure, leak-resistant seal and lasting durability, even in environments exposed to extreme heat or aggressive chemical conditions. We cater to bulk and custom orders across India, the UAE, KSA, Kuwait, Qatar, Oman, Iran, and Iraq.

Technical Overview

The SS 304 family is known for its versatility and mechanical performance. KVN Steels India, SS 304 is an 18/8 austenitic stainless steel flanges offering excellent corrosion resistance and good forming properties. In its annealed state, it is non-magnetic but can become magnetic after cold working. SS 304L, the low-carbon variant, is especially suitable for welded assemblies and resists carbide precipitation during welding. It offers exceptional oxidation resistance up to 899°C, with intermittent service possible at 816°C. SS 304H, on the other hand, contains a higher carbon content, which makes it ideal for high-temperature environments where greater strength is required. All three grades offer superior toughness, weldability, and ease of fabrication, making them suitable for challenging industrial settings.

Applications & Industry Use

SS 304/304L/304H Flanges are widely deployed across sectors that demand high corrosion resistance and structural strength. These include petrochemical plants, refineries, heat exchangers, water treatment systems, pharmaceutical production, specialty chemicals, construction projects, and power plants. Their consistent performance in both oxidizing and mildly reducing environments makes them a preferred choice for pipe-to-pipe, pipe-to-equipment, and pressure vessel connections. Each flange undergoes rigorous quality checks and is delivered with essential documentation such as MTCs, radiographic test reports, and heat treatment charts to ensure reliability and traceability.

304/304L/304H Stainless Steel Flanges Equivalent Grades

STANDARD	UNS	WNR.	AFNOR	EN	JIS	BS	GOST
SS 304	S30400	1.4301	Z7CN18‐09	X5CrNi18-10	SUS 304	304S31	08Х18Н10
SS 304L	S30403	1.4306/1.4307	Z3CN18‐10	X2CrNi18-9 / X2CrNi19-11	SUS 304L	304S11	03Х18Н11
SS 304H	S30409	1.4301	-	-	-	-	-

SS 304/304L/304H Slip On Flanges

ASME SA213 SS 304L /304H Seamless Tube, ASTM A213 Stainless Steel 304 Seamless Tubing, DIN 1.4301 / 1.4307 Seamless Tubes, UNS S30403 / S30409 Seamless Tube

SS 304/304L/304H Weld Neck Flanges

Stainless Steel 304 Seamless Pipes, UNS S30400 / S30403 / S30409 Seamless Pipes, DIN 1.4301 Seamless Pipes, ASME SA 312 SS TP304H Seamless Piping

SS 304/304L/304H Blind Flanges

ASME SA213 SS 304L /304H Seamless Tube, ASTM A213 Stainless Steel 304 Seamless Tubing, DIN 1.4301 / 1.4307 Seamless Tubes, UNS S30403 / S30409 Seamless Tube

SS 304/304L/304H Threaded Flanges

DIN 1.4301 Welded Tubing, UNS S30400 Welded Tube, ASME SA 213 Stainless Steel 304L Welded Tubes, ASTM A213 304H SS Welded Tubes

SS 304/304L/304H Socket Weld Flanges

ASME SA358 304 SS EFW Pipes, ASTM A358 TP304H Stainless Steel EFW Pipe, SS UNS S30400/ S30403/ S30409 EFW Pipes, SS DIN 1.4301 / 1.4306 EFW Pipes

SS 304/304L/304H Lap Joint Flanges

UNS S30400 ERW Pipes, Stainless Steel 304 ERW Tubing, ASTM A213 TP304L Stainless Steel ERW Tubes, ASME SA 312 SS 304H Pipe

SS 304/304L/304H Ring Type Joint Flange

ASME SA358 304 SS EFW Pipes, ASTM A358 TP304H Stainless Steel EFW Pipe, SS UNS S30400/ S30403/ S30409 EFW Pipes, SS DIN 1.4301 / 1.4306 EFW Pipes

SS 304/304L/304H Orifice Flanges

UNS S30400 ERW Pipes, Stainless Steel 304 ERW Tubing, ASTM A213 TP304L Stainless Steel ERW Tubes, ASME SA 312 SS 304H Pipe

SS 304/304L/304H Long Weld Neck Flanges

UNS S30409 Long Weld Neck Flanges, Stainless Steel 1.4307 Long Weld Neck Flanges, ASTM A182 F304L Stainless Steel Long Weld Neck Flanges, ASME SA 182 SS 304H Long Weld Neck Flanges

SS 304/304L/304H Spectacle Blind Flanges

UNS S30403 Spectacle Blind Flanges, ANSI / ASME B16.5 Stainless Steel 304 Spectacle Blind Flanges, ASTM A182 F304L Spectacle Blind Flanges, SA 182 SS 304H Spectacle Blind Flanges

SS 304/304L/304H Forged Flanges

UNS S30409 Forged Flanges, B16.5 Stainless Steel 304 Forged Flanges, ASTM A182 F304L Stainless Steel Forged Flanges, ASME SA 182 SS 304H Forged Flanges

SS 304/304L/304H Plate Flanges

UNS S30400 Plate Flanges, ANSI B16.5 Stainless Steel 304 Plate Flanges, ASTM A182 F304L Stainless Steel Plate Flanges, ASME SA 182 SS 304H Plate Flanges

Stainless Steel Flanges Specification :

ASTM A182 / ASME SA182

Dimension Standard :

ANSI/ASME B16.5, B 16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, etc.

Standard :

ANSI Flanges, ASME Flanges, BS Flanges, DIN Flanges, EN Flanges, etc.

Size :

1/2" (15 NB) to 48" (1200NB)

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)

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.

Chemical Composition of Stainless Steel 304/304L/304H Flanges

	C	Mn	Si	P	S	Cr	Ni	N
304	0.07max	2.0max	0.75max	0.045max	0.03max	min: 18.0 max: 20.0	min: 8.0 max: 10.5	—
304L	0.03max	2.0max	0.75max	0.045max	0.03max	min: 18.0 max: 20.0	min: 8.0 max: 12.0	0.10 max
304H	min: 18.0 max:20.0	min: 8.0 max: 10.5	min: 0.04 max:0.10	0.75 max	2.0 max	0.045 max	0.03 max	0.10 max

Mechanical Properties Of Stainless Steel 304/304L/304H Flanges

Grade	Tensile Strength ksi (min)	Yield Strength 0.2% ksi (min)	Elongation %	Hardness (Brinell) MAX	Hardness (Rockwell B) MAX
304	75	30	40	201	92
304L	70	25	40	201	92
304H	75	30	40	201	92

Physical Properties of 304/304L/304H Stainless Steel Flanges

SS 304/304L
Density lbm/in3	Thermal Conductivity (BTU/h ft. °F)	Electrical Resistivity (in x 10-6)	Modulus of Elasticity (psi x 106	Coefficient of Thermal Expansion (in/in)/ °F x 10-6	Specific Heat (BTU/lb/ °F)	Melting Range (°F)
at 68°F: 0.285	9.4 at 212°F	28.3 at 68°F	28	9.4 at 32 – 212°F	0.1200 at 68°F to 212°F	2500 to 2590
	12.4 at 932 °F	39.4 at 752°F		10.2 at 32 – 1000°F
		49.6 at 1652 °F		10.4 at 32 – 1500°F
SS 304H
Denstiy lbm/in3	Coefficient of Thermal Expansion (min/in)-°F		Thermal Conductivity BTU/hr-ft-°F		Specific Heat BTU/lbm -°F	Modules of Elasticity (annealed)2-psi
at 68 °F	at 68 – 212°F	at 68 – 1600°F	at 212°F	at 932°F	at 32 – 212°F	in tension (E)
0.285	9.2	11.0	9.4	12.4	0.12	29 x 106