ASTM A350 LF2 Weld Neck Flange Order

On December 12, 2024, we received an inquiry from an old customer in Vietnam, who needed a batch of ASTM A350 LF2 weld neck flange. We had cooperated with this customer many times before.

After receiving the quotation, the customer was very interested in the price and delivery time, and asked if we had produced similar products before. We provided the customer with product pictures and packaging pictures of previous orders, and the customer was very satisfied.

One month later, we received a purchase order from the customer.

Purchase list 

NO	Description	Material
1	FLANGE 1″ LWN RF L=157 300# ASME B16.5	SA-350 LF2 CL.1
2	FLANGE 1″ LWN RF L=159 300# ASME B16.5	SA-350 LF2 CL.1
3	FLANGE 2″ LWN RF L=154 300# ASME B16.5	SA-350 LF2 CL.1
4	FLANGE 2″ LWN RF L=176 300# ASME B16.5	SA-350 LF2 CL.1
5	FLANGE 1″ WN RF THK.4.55 300# ASME B16.5	SA-350 LF2 CL.1
6	FLANGE 10″ WN RF THK.12.7 150# ASME B16.5	SA-350 LF2 CL.1
7	FLANGE 16″ WN RF THK.12.7 150# ASME B16.5	SA-350 LF2 CL.1
8	FLANGE 16″ WN RF THK.9.53 150# ASME B16.5	SA-350 LF2 CL.1
9	FLANGE 2″ WN RF THK.5.54 300# ASME B16.5	SA-350 LF2 CL.1
10	FLANGE 24″ WN RF THK.10 150# ASME B16.5	SA-350 LF2 CL.1
11	FLANGE 24″ WN RF THK.12.7 150# ASME B16.5	SA-350 LF2 CL.1
12	FLANGE 28″ WN RF THK.12.7 150# ASME B16.47 SR.A	SA-350 LF2 CL.1
13	FLANGE 28″ WN RF THK.14 150# ASME B16.47 SR.A	SA-350 LF2 CL.1
14	FLANGE 32″ WN RF THK.14 150# ASME B16.47 SR.A	SA-350 LF2 CL.1
15	FLANGE 36″ WN RF THK.10 150# ASME B16.47 SR.A	SA-350 LF2 CL.1
16	FLANGE 36″ WN RF THK.12.7 150# ASME B16.47 SR.A	SA-350 LF2 CL.1
17	FLANGE 36″ WN RF THK.14 150# ASME B16.47 SR.A	SA-350 LF2 CL.1
18	FLANGE 6″ WN RF THK.10.97 150# ASME B16.5	SA-350 LF2 CL.1

Inspection photos

A350 LF2 Weld Neck Flange is a kind of pipe fittings, which refers to a flange with a neck and a round pipe transition and is butt welded to the pipe. ASTM A350 LF2 is a low-temperature carbon steel material used for forged flanges, fittings, and piping components. Weld Neck (WN) flanges made from A350 LF2 are designed for low-temperature applications requiring high toughness.

Key Features:

Designed for low-temperature applications, commonly used in cryogenic and cold environments

Excellent weldability and toughness

Heat-treated (normalized or normalized & tempered) to improve mechanical properties

Available in different pressure classes: 150, 300, 600, 900, 1500, and 2500

Specification of A350 LF2 Flange

Shape Type	Regular and Long Neck
Sealing Face	RF, FF, FTJ
Size Range	1/2″ – 48″/ DN15 – DN1200
Pressure Rating	Class 150, 300, 600, 900, 1500, 2500lb
Standard	ASME B16.5, ASME B16.47 Series A/B
Low Temp Carbon Steel	ASTM A350 LF2/LF3

 

ASTM A350 LF2 Chemical Composition

 

CHEMICAL	LIMITS	C	Mn	P	S	Si	Cu	Ni	Cr	Mo	V	Nb
ASTM A350 LF2	MIN		0.60			0.15
	MAX	0.30	1.35	0.035	0.040	0.35	0.40	0.40	0.30	0.12	0.08	0.02

 

ASTM A350 LF2 Mechanical Property

 

MATERIAL	T.S (MPA)	Y.S (MPA)	EL %	R/A %	HARDNESS
ASTM A350 LF2	485-655	250 min	22 min	30 min	197 max

 

Class 150 lb Weld Neck Flange Dimensions

 

NPS	A	B	C	D	E	F	G	H	I	J	W
	inch							No. of Holes	inch		kg/pc
	mm								mm
1/2	3.500	0.620	0.440	1.880	0.840	1.190	1.380	4	0.620	2.380	0.48
	88.90	15.70	11.20	47.80	21.30	30.20	35.00		15.70	60.45
3/4	3.880	0.820	0.500	2.060	1.050	1.500	1.690	4	0.620	2.750	0.71
	98.60	20.80	12.70	52.30	26.70	38.10	42.90		15.70	69.85
1	4.250	1.050	0.560	2.190	1.320	1.940	2.000	4	0.620	3.120	1.01
	108.0	26.70	14.20	55.60	33.50	49.30	50.80		15.70	79.25
1-1/4	4.620	1.380	0.620	2.250	1.660	2.310	2.550	4	0.620	3.500	1.33
	117.3	35.10	15.70	57.15	42.20	58.70	63.50		15.70	88.90
1-1/2	5.000	1.610	0.690	2.440	1.900	2.560	2.880	4	0.620	3.880	1.72
	127.0	40.90	17.50	62.00	48.30	65.00	73.15		15.70	98.60
2	6.000	2.070	0.750	2.500	2.380	3.060	3.620	4	0.750	4.750	2.58
	152.4	52.60	19.10	63.50	60.45	77.70	91.90		19.10	120.7
2-1/2	7.000	2.470	0.880	2.750	2.880	3.560	4.120	4	0.750	5.500	4.11
	177.8	62.70	22.40	69.85	73.15	90.40	104.6		19.10	139.7
3	7.500	3.070	0.940	2.750	3.500	4.250	5.000	4	0.750	6.000	4.92
	190.5	78.00	23.90	69.85	88.90	108.0	127.0		19.10	152.4
3-1/2	8.500	3.550	0.940	2.810	4.000	4.810	5.500	8	0.750	7.000	6.08
	215.9	90.20	23.90	71.40	101.6	122.2	139.7		19.10	177.8
4	9.000	4.030	0.940	3.000	4.500	5.310	6.190	8	0.750	7.500	6.84
	228.6	102.4	23.90	76.20	114.3	134.9	157.2		19.10	190.5
5	10.00	5.050	0.940	3.500	5.560	6.440	7.310	8	0.880	8.500	8.56
	254.0	128.3	23.90	88.90	141.2	163.6	185.7		22.40	215.9
6	11.00	6.070	1.000	3.500	6.630	7.560	8.500	8	0.880	9.500	10.6
	279.4	154.2	25.4	88.90	168.4	192.0	215.9		22.40	241.3
8	13.50	7.980	1.120	4.000	8.630	9.690	10.62	8	0.880	11.75	17.6
	342.9	202.7	28.40	101.6	219.2	246.1	269.7		22.40	298.5

 

Applications:

Oil & gas industry

Cryogenic services

Pressure vessel systems

Chemical processing plants

Power generation