Manufacturer Customized Flanges Weld Neck Flange Large Diameter Carbon Steel Forged Flanges

• Customization: Available
• Standard: ANSI, DIN, GB, JIS, GOST, BSW
• Type: Welding Flange
• Model NO.: custom
• Material: Carbon Steel
• Structure: Flanges
• Connection: Flanged
• Sealing Surface: RF
• Manufacturing Way: Forging
• Certificate: ISO9001
• Pressure: 150# 300# 400# 600# 900# 1500# 2500#
• Usage: Suitable for Water, Oil and Gas Industrial
• Connection Endstsocket Weld or Threaded: NPT, Bsp, BSPT etc
• Factory: Over 30 Years Experience
• Transport Package: Customized
• Specification: 1/2"-24"
• Trademark: GUCHENG
• Origin: Dingxiang
• HS Code: 73079100
• Production Capacity: 50000 Pieces/Year

Product Description

ASME/ANSI B16.5 FORGING FLANGE -- Welding Neck Flange Class 600 - Piping & Pipeline 

The welding neck flange (WN) conforming to ASME/ANSI B16.5 is a typical integral-type flange. It is forged integrally with the tapered neck which is butt welded to the pipe. This design provides a smooth transition with little stress concentration since transferring stress to the adjoining pipe reduces the high-stress concentration at the base of the flange. There are no gaps or recesses that could lead to crevice corrosion. The tapered neck is also known as the "nozzle neck" or "high hub". Although expensive, the welding neck flange is the best-designed butt weld flange available since the long tapered hub provides superior strength and resistance to dishing.

According to ASME B16.5, the hub of the welding neck flange can be roughly divided into a tapered portion and a straight length. The straight length of 6 mm is machined to precisely match with the adjoining pipe so that the welding can be done conveniently. Weld neck flanges are bored to match the inside diameter of the adjoining pipe. The thinner the wall of the pipe, the larger the bore through the flange. The thicker the wall of the pipe, the smaller the bore. Because of these matching relationship, there is no restriction to the flow. Turbulence and erosion are therefore eliminated.

The ASME B16.5 welding neck flange shall be furnished with cut square end when wall thickness is less than 5 mm, plain bevel end when wall thickness is from 5 mm to 22 mm inclusive, or compound bevel end when wall thickness is greater than 22 mm. The butt welding ends shall be machined in accordance with the requirements of ASME B16.25. The dimensions and tolerances of plain bevel and compound bevel are illustrated in below two drawings. In particular, the wall thickness t shall conforming to the adjoining pipe's wall thickness requirement; a root face in width f of 2 mm shall be machined at the top of the bevel with tolerance of ±1 mm.

Three most common facing types are available including flat face (FF), raised face (RF), and ring joint face (RTJ). Welding neck flanges are normally used in severe service applications involving high pressures, high temperatures, large external loads or cryogenic conditions.

The Welding neck flanges are available across various materials: Cabon Steel, Stainless steel, Duplex Steel.......

Product Parameters

Slip-On Flange (SO)	Weld Neck Flange (WN)	Socket Weld Flange (SW)
Threaded Flange (TH)	Lap Joint Flange (LJ)	Blind Flange (BL)

 

Nominal Pipe Size	Outside Dlam.	Diam. at Base of Hub	0,D,of Raised Face	Thickness	BORE					LENGTH   THRU   HUB			Diam.of Hub at Bevel	Radius   of   Filet	Thread Length
					Welding Neck Socket Welding		Slip-on Socket Welding	Lap Joint	Counter   Bore  Min	Welding Neck	Slip-on Threaded Socket Welding	Lap Joint
	D	X	G	t	B1		B2	B3	B	T1	T2	T3	A	R	Q
1/2	95	38.1	35.1	14.2	See Note(1) To be specified by purchaser		22.4	22.9	23.6	52.3	22.4	22.4	21.3	3.0	15.7
3/4	117	47.8	42.9	15.7			27.7	28.2	29.0	57.2	25.4	25.4	26.7	3.0	15.7
1	124	53.8	50.8	17.5			34.5	35.1	35.8	62.0	26.9	26.9	33.5	3.0	17.5
1 1/4	133	63.5	63.5	20.6			43.2	43.7	44.5	66.5	28.4	28.4	42.2	4.8	20.6
1 1/2	155	69.9	73.2	22.4			49.5	50.0	50.5	69.9	31.8	31.8	48.3	6.4	22.4
2	165	84.1	91.9	25.4			62.0	62.5	63.5	73.2	36.6	36.6	60.5	7.9	28.4
2 1/2	191	100.1	104.6	28.4			74.7	75.4	76.2	79.2	41.1	41.1	73.2	7.9	31.8
3	210	117.3	127.0	31.8			90.7	91.4	92.2	82.6	46.0	46.0	88.9	9.7	35.1
3 1/2	229	133.4	139.7	35.1			103.4	104.1	104.9	85.9	49.3	49.3	101.6	9.7	39.6
4	273	152.4	157.2	38.1			116.1	116.8	117.6	101.6	53.8	53.8	114.3	11.2	41.1
5	330	189.0	185.7	44.5			143.8	144.5	144.5	114.3	60.5	60.5	141.2	11.2	47.8
6	356	222.3	215.9	47.8			170.7	171.6	171.5	117.3	66.5	66.5	168.4	12.7	50.8
8	419	273.1	269.7	55.6			221.5	222.3	222.3	133.4	76.2	76.2	219.2	12.7	57.2
10	508	342.9	323.9	63.5			276.4	277.4	276.4	152.4	85.9	111.3	273.1	12.7	65.0
12	559	400.1	381.0	66.5			327.2	328.2	328.7	155.4	91.9	117.3	323.9	12.7	69.9
14	603	431.8	412.8	69.9			359.2	360.2	360.4	165.1	93.7	127.0	355.6	12.7	73.2
16	686	495.3	469.9	76.2			410.5	411.2	411.2	177.8	106.4	139.7	406.4	12.7	77.7
18	743	546.1	533.4	82.6			461.8	462.3	462.0	184.2	117.3	152.4	457.2	12.7	79.2
20	813	609.6	584.2	88.9			513.1	514.4	512.8	190.5	127.0	165.1	508.0	12.7	82.6
24	940	717.6	692.2	101.6			616.0	616.0	614.4	203.2	139.7	184.2	609.6	12.7	91.9

 

Nomina Pipe Size	Depth of Socket	DRILLING			BOLTING				APPROXIMATE     WEIGHT
					Dlam of Bolt (Inch)	Stud Bolt Lenglh
		Bolt Clrcle Dlam.	Number of Holes	Dlam of Holes		0.25" Raised Face	Male- Female Tongue -Groove	Ring Joint	Welding Neck		Sllp-on and Threaded		Lap Jolnt		Bllnd		Socket Weldlng
	Y								Kg	lb	Kg	Ib	Kg	Ib	Kg	lb	Kg	Ib
1/2	9.7	66.5	4	15.7	1/2	76.2	69.9	76.2	0.90	2.00	0.91	2.00	0.80	1.80	0.91	2.00	0.91	2.00
3/4	11.2	82.6	4	19.1	5/8	88.9	82.6	88.9	1.59	3.50	1.40	3.00	1.36	3.00	1.40	3.00	1.36	3.00
1	12.7	88.9	4	19.1	5/8	88.9	82.6	88.9	1.90	4.00	1.70	3.70	1.59	3.50	1.81	4.00	1.81	4.00
1 1/4	14.2	98.6	4	19.1	5/8	95.3	88.9	95.3	2.49	5.50	2.27	5.00	2.04	4.50	2.40	5.30	2.60	5.70
1 1/2	15.7	114.3	4	22.4	3/4	108.0	101.6	108.0	3.63	8.00	3.10	6.80	2.95	6.50	3.40	7.50	3.18	7.00
2	17.5	127.0	8	19.1	5/8	108.0	101.6	108.0	4.54	10.00	3.63	8.00	3.63	8.00	4.40	9.70	3.90	8.60
2 1/2	19.1	149.4	8	22.4	3/4	120.7	114.3	120.7	6.35	14.00	5.44	12.00	4.99	11.00	6.80	15.00	5.90	13.00
3	20.6	168.1	8	22.4	3/4	127.0	120.7	127.0	8.16	18.00	7.26	16.00	6.35	14.00	8.90	19.60	7.40	16.30
3 1/2	22.4	184.2	8	22.4	7/8	139.7	133.4	139.7	11.80	26.00	9.53	21.00	9.08	20.00	13.17	29.00
4	23.9	215.9	8	25.4	7/8	146.1	139.7	146.1	16.78	37.00	14.97	33.00	14.06	31.00	18.60	41.00
5	23.9	266.7	8	28.4	1	165.1	158.8	165.1	30.87	68.00	28.50	62.80	27.50	60.60	30.84	68.00
6	26.9	292.1	12	28.4	1	171.5	165.1	171.5	36.77	80.00	36.32	80.00	35.38	78.00	38.00	83.80
8	31.8	349.3	12	31.8	1 1/8	190.5	184.2	196.9	50.80	112.00	44.00	97.00	50.80	112.00	62.20	137.00
10	33.3	431.8	16	35.1	1 1/4	215.9	209.6	215.9	86.26	190.00	76.20	168.00	74.00	163.00	102.00	224.90
12	39.6	489.0	20	35.1	1 1/4	222.3	215.9	222.3	102.51	226.00	97.52	215.00	108.86	240.00	132.00	291.00
14	41.4	527.1	20	38.1	1 3/8	235.0	228.6	235.0	121.56	268.00	102.00	224.80	111.00	244.70	158.00	348.30
16	44.5	603.3	20	41.1	1 1/2	254.0	247.7	254.0	177.06	290.00	149.82	330.20	165.71	365.30	224.73	495.40
18	49.3	654.1	20	44.5	1 5/8	273.1	266.7	273.1	215.65	475.40	180.10	412.30	194.00	427.70	285.00	628.30
20	54.1	723.9	24	44.5	1 5/8	285.8	279.4	292.1	267.86	590.50	231.54	510.50	258.78	570.50	365.00	804.70
24	63.5	838.2	24	50.8	1 7/8	330.2	323.9	336.6	372.00	820.00	330.00	725.50	362.00	798.00	533.45	1176.0

Notes:
(1) For the inside diameter of pipes (corresponding to 'Bore' (B1) of Welding Neck Flanges), refer to page 60.
(2) Class 600 flanges except Lap Joint will be furnished with  0.25" (6,35mm) raised face, which is not included in thickness'(t) and Length through Hub'(Ti),(T2).
(3) For Slip-on, Threaded, and Lap Joint and Socket Welding Flanges, the hubs can be shaped either vertically from base to top or tapered within the limits of  7 degrees.
(4) Blind Flanges may be made with the same hub as that used for Sllp-on Flanges or without a hub.
(5) The gasket surface and backside (bearing surface for bolting) are made parallel within 1 degree. To accomplish parcels, spot facing is scared out according to MSS SP-9, without reducing thickness(t).
(6) Dimensions of sizes 1/2" through 3 1/2" are the same as for Class 400 Flanges.
(7) Depth of Socket (Y) is covered by ANSI B16.5 only in sizes through 3 inch, over 3 inch is at the manufacturer's optlon. 

ANSI B16.5 FORGED FLANGES TOLERANCE

THREAD,SOCKET-WELDING,                                                    SLIP-ON,LAP JOINT AND BLIND.			WELDING NECK
Outside Diameter	When O.D.is 24"or less	±1/16"(1.6mm)	Outside Diameter	When O.D.is 24"or less	±1/16"(1.6mm)*
	When O.D.is Over  24"	±1/8"(3.2mm)*		When O.D.is Over  24"	±18"(3.2mm)
Inside Diameter	Threaded	Within limits on boring gauge	Inside Diameter	10"and Smaller	±1/32"(0.8mm)
				20"thru 18"	±1/16"(1.6mm)
	Socket-Welding Slip-on and Lap joint	10"&Smaller +1/32"(0.8mm).0" 12"&Larger +1/16"(1.6mm).O"		20"and Larger	+1/8"(3.2mm) -1/16"(1.6mm)
Outside Diameter of Hub	5"and Smaller	+3/32"(2.4mm) -1/32"(0.8mm)	Diameter of Hub at Base	When Hub Base is 24"or Smaller	±1/16"(1.6mm)*
	6"and Larger	+5/32"(4.0mm) -1/32"(0.8mm)		When Hub Base is Over  24"	±1/8"(3.2mm)*
Diameter of Contact Face	1/16"Raised Face	±1/32"(0.8mm)	Diameter of Contact Face	116"Raised Face	±1/32"(0.8mm)
	1/4"Raised Face Tongue & Groove Male,Female	±1/64"(0.4mm)		14"Raised Face Tongue &Groove Male,Female	±1/64"(0.4mm)
Diameter of Counterbore	Same as for Inside Diameter		Diameter of Hub at Point of Welding	5"and Smaller	+3/32"(2.4mm)* -1/32"(0.8mm)
				6"and Larger	+5/32"(4.0mm) -1/32"(0.8mm)
Drilling	Bolt Circle	±1/16"(1.6mm)	Drilling	Bolt Circle	±1/16"(1.6mm)
	Bolt Hole Spacing	±1/32"(0.8mm)		Bolt Hole Spacing	±1/32"(0.8mm)
	Eccentricity of Bolt Circle with Respect to Facing	21/2"Smaller 1/32"(0.8mm)Max. 3"&Larger 1/16"(1.6mm)Max		Eccentricity of Bolt Circle with Respect to Facing	21/2"Smaller 1/32"(0.8mm)Max. 3"&Larger 1/16"(1.6mm)Max.
	Eccentricity of Bolt Circle with Respect to Bore	1/32"(0.8mm)Max.*		Eccentricity of Bolt Circle with Respect to Bore	1/32"(0.8mm)Max.*
	Eccentricity of Facing with Respect to Bore	1/32"(0.8mm)Max.*		Eccentricity of Facing with Respect to Bore	1/32"(0.8mm)Max.*
Thickness	18"and Smaller	+1/8"(3.2mm).0^	Thickness	18"and Smaller	+1/8"(3.2mm),0"
	20"and Larger	+3/16"(4.8mm).04		20"and Larger	+3/16"(4.8mm).O
Length Thru Hub	10"and Smaller	±1/16"(1.6mm)	Length Thru Hub	10"and Smaller	±1/16"(1.6mm)
	12"and Larger	±1/8"(3.2mm)		12"and Larger	±1/8"(3.2mm)

Notes:
This tolerance is not covered in ANSI B16.5, but maker's option.

STANDARD FINISHES for Face of Flange (ANSI  B16.5)
STOCK FINISH:
The most widely used gasket finish.because practically is suitable for all ordinary service conditions. This is a continuous spiral groove. Flanges size 12" (304.8mm)and smaller are produced with a 1/16" round-nosed tool at a feed of 1/32" per revolution. For sizes 14" (355.6mm)and larger. the finish is made with a 1/8" round-nosed tool at a feed of 3/64" per revolution.
SPIRAL SERRATED OR PHONOGRAPHIC:
This finish is produced by using a 90°round-nosed tool.
CONCENTRIC SERRATED:
This finish is produced by using a 90°round-nosed tool.
SMOOTH  FINISH:
The cutting tool employed shall have an approximate 0.06"radius.
The resultant surface finish shall have a 125μ inch to 250μ inch(ANSI B16.5 para 6.4;4.1)
1. RAISED FACE AND LARGE MALE AND FEMALE
    A serrated-concentric or serrated-spiral finish with 34 to 64 grooves per inch is used.
    The cutting tool employed has an approximate 0.06 in.radius.The resultant surface finish shall have a 125μ inch(3.2m)to 500μ inch(12.5μm) approximate roughness.
2. TONGUE AND GROOVE AND SMALL MALE AND FEMALE
    The gasket contact surface does not exceed 125μ in. (3.2μm)roughness
3. RING JOINT
    The inside wall surface of the gasket groove does not exceed 63μin.(1.6μm)roughness,
4. BLIND
    Blind flanges need not be faced in the center if, when this center part is raised, its diameter is at least 1 in. smaller than the inside diameter of the corresponding pressure class fittings. When the center part is depressed, its diameter is not greater than the inside diameter of the corresponding pressure class fittings. Machining of the depressed center is not required.

The manufacturing process of forged flanges begins with the selection of high-quality steel, which is heated and shaped under high pressure in forging dies to enhance its strength and durability. After forging, the flanges are trimmed, heat-treated to relieve internal stresses, and precisely machined to meet the required dimensions. They undergo rigorous inspection and testing for quality assurance, followed by surface treatments for enhanced corrosion resistance. This process results in flanges that are strong, reliable, and suitable for demanding industrial environments.

Company Profile

Dingxiang Country Gu Cheng Forging Company Ltd.  is a leading manufacturer in Dingxiang County, Shanxi Province, known as the "Forging Capital of China." Established with a deep-rooted history in forging, we specialize in producing high-quality flanges and forged components for a wide range of industrial applications. Our extensive product line includes ANSI, DIN, JIS, and EN standard flanges and customized forged parts designed to meet specific customer requirements.

Gu Cheng Forging with over 30 years of experience in producing high-quality forged flanges. Including Weld Neck Flange (WN), Slip-On Flange (SO), Blind Flange (BL), Socket Weld Flange (SW), Lap Joint Flange, Plate Flange, and Customized forged flange.

At Gu Cheng Forging, we serve a global market, providing flanges and forged components for industries such as oil and gas, chemical processing, power generation, shipbuilding, and more. We pride ourselves on our ability to deliver tailored solutions, meeting the highest standard of safety, performance, and efficiency.

As a factory, we can tailor flanges based on your specific requirements for size, material, pressure rating, and surface treatment (galvanization, black paint, etc.). By preventing rust and deterioration, the coating enhances the flange's performance, offering long-term resilience and reducing maintenance needs over time.

Dingxiang Country Gu Cheng Forging Company Ltd,  strives to be a trusted partner for all your forging needs, ensuring long-term cooperation and mutual success.

Q1: Are you a manufacturer or a trading company?
A1: We are a professional manufacturer with over 30 years of experience in forging flanges. Our factory is located in Dingxiang, China, known as the "Forging Capital." We produce high-quality, customized forged flanges, offering factory-direct pricing and ensuring top-notch quality.

Q2: What types of flanges do you produce?
A2: We manufacture a wide range of forged flanges, including:

• Weld Neck Flange (WN)
• Slip-On Flange (SO)
• Blind Flange (BL)
• Socket Weld Flange (SW)
• Threaded Flange (TH)
• Lap Joint Flange
• Plate Flange

All our flanges comply with international standards such as ASME, DIN, JIS, and BS.

Q3: What materials do you use?
A3: We offer flanges in a variety of materials, including:

• Carbon Steel
• Stainless Steel
• Alloy Steel

Each material is sourced from certified suppliers, ensuring durability and performance in diverse industrial applications.

Q4: Can you provide customized flanges?
A4: Absolutely! As a factory, we specialize in customization. We can tailor flanges based on your specific requirements for size, material, pressure rating, and surface treatment (galvanization, black paint, etc.).

Q5: How do you ensure the quality of your products?
A5: Quality is our top priority. Every flange undergoes a strict inspection process, including:

• Material analysis
• Dimensional checks
• Pressure testing
• Surface treatment inspections

Our CNC machining ensures precise dimensions, and we adhere to strict international standards throughout the manufacturing process.