Editorial Technical Reference

Forged Steel Flange

This page explains how Forged Steel Flange is classified within Metal Forging, Pressing, Stamping. Technical values and manufacturer relationships are research references; confirm the current specification and supplier evidence for each order.

Technical Definition & Core Assembly

Forged steel ring with bolt holes for connecting pipes, valves, or equipment in industrial piping systems.

Representative product image. Confirm appearance and specifications with the manufacturer.

Product Specifications

Technical details and manufacturing context for Forged Steel Flange

Definition
A forged steel flange is a circular metal component with bolt holes used to connect pipes, valves, pumps, and other equipment in industrial piping systems. It provides a strong, leak-proof joint that can withstand high pressure and temperature conditions. These flanges are manufactured through metal forging processes for superior strength and durability compared to cast alternatives. They are standardized components sold individually in B2B supply chains for assembly into larger systems.

Forged steel flanges are available in carbon steel, stainless steel, and alloy steel. Common material grades include A105, F304, and F316, as referenced in ASTM A105 and A182 standards. The nominal diameter ranges from 15 to 600 mm per ISO 7005-1, and pressure classes from 150 to 2500 per ASME B16.5. Bolt circle diameters range from 60.3 to 774.7 mm, with 4 to 32 bolt holes of 16 to 33 mm diameter. Flange thickness varies from 14.3 to 63.5 mm. Operating temperature ranges from -40°C to 400°C, with derating required above 400°C. Surface finish for sealing is 3.2 to 6.3 μm Ra per ISO 1302. Weight ranges from 0.5 to 450 kg depending on size and pressure class. General machining tolerance is ±0.5 mm per ISO 2768-m.

These flanges are standardized components sold individually in B2B supply chains for assembly into larger systems. They are used in various industries including oil and gas, chemical processing, water treatment, and power generation. When selecting a forged steel flange, verify model-specific values and standards with the legal manufacturer or supplier, as actual dimensions and ratings may vary.
Working Principle
The flange creates a sealed connection between components via bolted assembly with a gasket. The flange faces are machined to a specified surface finish to ensure proper gasket seating. When bolts are tightened, the gasket is compressed between the flange faces, forming a leak-tight seal. The bolted joint provides mechanical strength to withstand internal pressure and external loads. The flange's material and design must match the operating pressure, temperature, and fluid compatibility. Proper bolt torque and gasket selection are critical for reliable sealing. Regular inspection of bolt tension and gasket condition is necessary to maintain joint integrity.
Common Materials
carbon steel, stainless steel, alloy steel
Technical Parameters
ParameterTypical rangeNotes & selection driver
Nominal DiameterRequired15–600 mmPipe connection sizeISO 7005-1
Pressure ClassRequired150–2500 classPressure rating (150, 300, 600, etc.)ASME B16.5
Bolt Circle DiameterRequired60.3–774.7 mmDiameter of bolt hole circleASME B16.5
Number of Bolt HolesRequired4–32 holesTotal bolt holesASME B16.5
Bolt Hole DiameterRequired16–33 mmDiameter of bolt holesASME B16.5
Flange ThicknessRequired14.3–63.5 mmThickness of flange bodyASME B16.5
Operating Pressure1.0–1.6 MPaBelow 1.0 MPa the seat load is insufficientISO 5208
Operating Temperature-40–400 °CMaterial dependent; above 400°C derating requiredASME B16.5
Material GradeA105, F304, F316Carbon steel or stainless steelASTM A105, A182
Surface Finish3.2–6.3 μm RaSealing surface finish for gasketISO 1302
Weight0.5–450 kgDepends on size and pressure class
Tolerance±0.5 mmGeneral machining toleranceISO 2768-m

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM
  • Flange Body Part
    Main structural ring
    Material: Steel
  • Sealing Face Part
    Gasket contact surface
    Material: Steel
  • Hub Optional Part
    Pipe connection section
    Material: Steel

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Forged Steel Flange.

Industrial Ecosystem & Supply Chain Structure

Complementary Systems
Downstream Applications
Specialized Tooling

Application Fit & Sizing Matrix

Operational Limits
pressure: Up to 2500 psi (172 bar) for standard ANSI B16.5 Class 150-2500
other spec: Flow Rate: Dependent on pipe size and system design; Slurry Concentration: Suitable for moderate abrasion, not recommended for highly erosive slurries >40% solids by weight
temperature: -20°C to 540°C (-4°F to 1004°F)
Media Compatibility
✓ High-pressure steam systems ✓ Hydrocarbon processing (oil/gas) ✓ Chemical processing with non-corrosive media
Unsuitable: Highly corrosive environments with concentrated acids (e.g., hydrochloric acid >10%)
Sizing Data Required
  • Nominal Pipe Size (NPS) and schedule/thickness
  • Pressure Class Rating (e.g., ANSI 150, 300, 600)
  • Flange facing type and dimensions (e.g., RF, FF, RTJ)

Reliability & Engineering Risk Analysis

Failure Mode & Root Cause
Stress corrosion cracking
Cause: Combination of tensile stress from bolting/thermal cycling and corrosive environment (e.g., chlorides, sulfides) attacking the steel microstructure
Flange face distortion/warping
Cause: Excessive bolt torque during installation causing uneven stress distribution, or thermal shock from rapid temperature changes exceeding material yield strength
Maintenance Indicators
  • Visible radial cracks or pitting corrosion on flange face or hub region
  • Audible hissing or detectable gas leak at flange connection during pressure testing
Engineering Tips
  • Implement controlled bolt tightening sequence using calibrated torque wrenches with cross-pattern tightening to ensure even gasket compression
  • Apply protective coatings (e.g., zinc-rich epoxy) on flange exterior surfaces and specify compatible gasket materials to prevent galvanic corrosion

Indicative industry ranges for design and RFQ preparation. Confirm the exact figures and applicable standard with the manufacturer before specifying.

Compliance & Manufacturing Standards

Applicable Standards
ASTM A105/A105M - Standard Specification for Carbon Steel Forgings for Piping Applications ASME B16.5 - Pipe Flanges and Flanged Fittings ISO 7005-1 - Metallic flanges - Part 1: Steel flanges

Quoted from the published standard.

Manufacturing Precision
  • Bore Diameter: +/- 0.02 mm
  • Flange Face Flatness: 0.1 mm
Quality Inspection
  • Dye Penetrant Test (PT) for surface defects
  • Ultrasonic Testing (UT) for internal flaws

Manufacturers of Forged Steel Flange

12 companies list this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

Jianen Sanitary
Wenzhou, Zhejiang, CN
Founded 2009
3A CE ISO9001 SGS
Listed on the company's own website · profile compiled by CNFX from public sources
Jiangsu Huixuan New Energy Equipment Co., Ltd.
Zhangjiagang, Jiangsu, CN
ISO BV SGS IST +2
Stated by the company · profile compiled by CNFX from public sources
Jiangyin Xinyu Forging Co., Ltd.
Jiangyin, Jiangsu, CN
Founded 2004
ISO 9001 API Spec 20B TÜV PED
Also makes: Steel Forging
Stated by the company · profile compiled by CNFX from public sources
Shandong Dechengxin Metal Products Co., Ltd.
Qingdao, Shandong, CN
Listed on the company's own website · profile compiled by CNFX from public sources
Sunthai Extractor
Zhejiang, CN
200-500 staff20,000 m²
ISO 9001:2015
Listed on the company's own website · profile compiled by CNFX from public sources
VIGOR INNO-TECH Limited
Shaanxi, CN
Founded 2007
Listed on the company's own website · profile compiled by CNFX from public sources
Epowermetals
Zhejiang, CN
Also makes: Butterfly Valve, Heat Exchanger, Steel Forging and 7 more
Listed on the company's own website · profile compiled by CNFX from public sources
Hebei Haihao Flange Factory
Hebei, CN
Listed on the company's own website · profile compiled by CNFX from public sources
Huili Water Tank
Shandong, CN
Listed on the company's own website · profile compiled by CNFX from public sources
Longan Flange
Zhejiang, CN
Also makes: Pressure Vessel
Listed on the company's own website · profile compiled by CNFX from public sources
Risen Metal
Cangzhou, Hebei, CN
Also makes: Butterfly Valve, Check Valves, Globe Valve and 4 more
Listed on the company's own website · profile compiled by CNFX from public sources
Shanghai Chantway Protech Co.,ltd
Shanghai, CN
Listed on the company's own website · profile compiled by CNFX from public sources
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Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

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Frequently Asked Questions

What materials are available for forged steel flanges?

Forged steel flanges are available in carbon steel, stainless steel, and alloy steel. Common material grades include A105, F304, and F316, as referenced in ASTM A105 and A182 standards. The specific material grade should be selected based on the application's pressure, temperature, and corrosion requirements.

What are the typical pressure and temperature ratings?

Pressure classes range from 150 to 2500 per ASME B16.5. Operating temperature ranges from -40°C to 400°C, with derating required above 400°C. Always verify the exact ratings for the specific flange model with the manufacturer.

How do I select the correct flange size?

The nominal diameter ranges from 15 to 600 mm per ISO 7005-1. The flange size must match the pipe connection size. Additionally, consider the pressure class, bolt circle diameter, number of bolt holes, and flange thickness, which are specified in ASME B16.5. Consult the manufacturer's data for the specific flange model.

What standards apply to forged steel flanges?

Key standards include ISO 7005-1 for nominal diameters, ASME B16.5 for pressure classes and dimensions, and ISO 1302 for surface finish. Material grades are referenced in ASTM A105 and A182. These standards serve as procurement references; verify compliance with the supplier.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification
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