Factory Made Class 900# Long Weld Neck Standard Connection Flanges

Product Details
Customization: Available
Standard: ANSI, DIN, GB, JIS, GOST, BSW
Type: Welding Flange
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  • Factory Made Class 900# Long Weld Neck Standard Connection Flanges
  • Factory Made Class 900# Long Weld Neck Standard Connection Flanges
  • Factory Made Class 900# Long Weld Neck Standard Connection Flanges
  • Factory Made Class 900# Long Weld Neck Standard Connection Flanges
  • Factory Made Class 900# Long Weld Neck Standard Connection Flanges
  • Factory Made Class 900# Long Weld Neck Standard Connection Flanges
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  • Overview
  • Product Parameters
  • Company Profile
Overview

Basic Info.

Model NO.
3" - 24"
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 25 Years Experience
Transport Package
Customized
Specification
1/2"-24"
Trademark
GUCHENG
Origin
Dingxiang
HS Code
73079100
Production Capacity
50000 Pieces/Year

Product Description

Factory Made Class 900# Long Weld Neck Standard Connection Flanges

Factory Made Class 900# Long Weld Neck Standard Connection Flanges

ANSI B16.5 FORGING FLANGE -- Class 900 Long Weld Neck Flange

Long welding neck flange (LWN) is also known as straight hub welding flange. The LWN flange is constructed in two sections: the upper section is a heavy-wall barrel, while the lower section is a disc-like plate flange with all dimensions conforming to ASME B16.5 standard flanges.

According to ASME B16.5, The long welding neck flange is mainly applied to the construction of a pressure vessel functioning as a nozzle (such as a thermowell nozzle). To attach a common welding neck flange to a pressure vessel, a piece of pipe is required with additional welding. A LWN flange on the other hand attaches directly to the vessel, hence, it can be viewed as an integrally reinforced nozzle. It avoids making a weld seam at the pipe to the flange and provides self-reinforcement.

Product Parameters

Factory Made Class 900# Long Weld Neck Standard Connection Flanges Factory Made Class 900# Long Weld Neck Standard Connection Flanges
 
Nominal
Pipe
Size
Outside
Diameter
O.D. of
Raisad Face
Hub Diameler
at Beval
Diameter
of Bore
Thickness of
Flange Min.
Length
Through Hub
DRILLING
Diameter of
Bolt Circle
Number o
Holes
Diameter of
Holos
D G E B t L C d
3 241 127.0 127.0 76.2 38.1 304.8  190.5 8 25.4
4 1/2 292 157.2  158.8  101.6  44.5  304.8  235.0  8 31.8
5 349 185.7  190.5  127.0  50.8  304.8  279.4  8 35.1
6 381 215.9 235.0 162.4 55.6 304.8 317.5 12 31.8
8 470 269.7  298.5  203.2  63.5  304.8  393.7  12 38.1
10 546 323.9  368.3  254.0  69.9  406.4  469.9  16 38.1
12 610 381.0  419.1  304.8  79.2  406.4  533.4  20 38.1
14 641 412.8  450.9  355.6  85.9  To be specified
by Purchaser
558.8  20 41.1
16 705 469.9  508.0  408.4 88.9  616.0 20 44.5
18 787 633.4  565.2 457.2  101.6 685.8  20 50.8
20 857 684.2  622.3  508.0 108.0 749.3  20 53.8
24 1041 692.2  749.3  609.6  139.7  901.7  20 66.5

Notes:
(1) Bore(B) is not the same as the nominal pipe size.
(2) Welding necks longer than listed are available in all sizes on special order.

ANSI B16.5 FORGED FLANGES TOLERANCE
Factory Made Class 900# Long Weld Neck Standard Connection Flanges
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)
Factory Made Class 900# Long Weld Neck Standard Connection Flanges
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.

Factory Made Class 900# Long Weld Neck Standard Connection FlangesThe 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.
Factory Made Class 900# Long Weld Neck Standard Connection FlangesFactory Made Class 900# Long Weld Neck Standard Connection Flanges

Company Profile

Factory Made Class 900# Long Weld Neck Standard Connection FlangesDingxiang 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 FlangePlate 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.

Factory Made Class 900# Long Weld Neck Standard Connection FlangesFactory Made Class 900# Long Weld Neck Standard Connection FlangesFactory Made Class 900# Long Weld Neck Standard Connection FlangesFactory Made Class 900# Long Weld Neck Standard Connection Flanges

Factory Made Class 900# Long Weld Neck Standard Connection FlangesFactory Made Class 900# Long Weld Neck Standard Connection FlangesFactory Made Class 900# Long Weld Neck Standard Connection Flanges

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.
Factory Made Class 900# Long Weld Neck Standard Connection Flanges

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