ASME SA182 F304 Stainless Steel Flange | OD 520mm * ID 361mm * THK 85mm – Forged Heat Exchanger Flange for Shell & Tube Connections
Yuhong Group: Complete Heat Exchanger Components – From Tubes to Flanges
Yuhong Group Co., Ltd. designs and manufactures a comprehensive range of thermal equipment for global industries. Our core offerings include shell and tube heat exchangers, pressure vessels, air coolers, and a complete supply of critical components: finned tube bundles, U-tube bundles, heat exchanger tubesheets, and all related parts – including forged flanges for pressure-containing connections. Our full-service approach ensures you get exactly what you need for new projects or maintenance.
Shown in the attached photographs is one of our ASME SA182 F304 stainless steel flanges – a forged component precision-machined for heat exchanger shell, channel, or piping connections.
Product Focus: F304 Forged Stainless Steel Flange – Versatile & Corrosion-Resistant
The flange is a critical pressure-retaining component that provides leak-tight bolted connections between heat exchanger sections (channel to shell, shell to cover) or between the exchanger and process piping.
Based on the images, this flange exhibits:
Material: ASME SA182 F304 (forged 304 stainless steel)
Dimensions: OD 520mm * ID 361mm * THK 85mm (as stamped on the part)
Manufacturing method: Forged (dense grain structure, no internal porosity)
Machining: Precision-machined face with bolt holes for stud bolts and gasket seating
Marking: Full traceability with material grade, dimensions, and heat number (HEAT NO.: 23XH03K0)
Why F304 Stainless Steel for Flanges?
| Property | Benefit for Flange Application |
|---|---|
| 304 stainless steel | Excellent corrosion resistance for a wide range of chemical, food, and general industrial services. |
| Forged construction | Uniform grain structure – superior to cast or plate flanges – no internal voids or porosity. |
| ASME SA182 certified | Full traceability to ASME Section II material specifications. |
| Good machinability | Easy to drill and face for precise bolting and sealing. |
| Wide temperature range | Suitable for cryogenic to elevated temperature service (up to ~800°C). |
| Heat number traceability | Each flange is stamped with heat number for full material traceability. |
Key Components That Interface with This Flange
| Component | Material (Typical) | How It Interfaces with the Flange |
|---|---|---|
| Heat Exchanger Shell | Carbon steel or stainless steel | Welded to the flange – flange provides the connection point. |
| Channel / Bonnet | Carbon steel or stainless steel | Bolted to the flange – flange seals the channel end. |
| Gasket | Spiral-wound, PTFE, or metal-jacketed | Seals between the flange faces – prevents leakage. |
| Stud Bolts & Nuts | SA193 B8 / SA194 8 (stainless) or B7/2H (carbon steel) | Pass through bolt holes; clamp the flange to the mating component. |
| Heat Exchanger Tube | Stainless steel or carbon steel | Not directly connected – flange provides access to the tube bundle inside. |
| Finned Tube Bundle (optional) | Tube + aluminum/SS fins | Accessible through the flanged opening for inspection and maintenance. |
Technical Highlights of Our F304 Forged Flange
Forged, not cast: Forging eliminates internal porosity and provides superior mechanical properties – essential for pressure-retaining components.
Precision machining: The sealing face is machined to the required surface finish (typically 125-250 RMS for spiral-wound gaskets, or smoother for RTJ).
Bolt hole accuracy: Bolt holes are drilled on exact pitch circle – ensures proper bolt alignment during assembly.
Full traceability: Each flange is stamped with material grade, dimensions, heat number, and project number (as shown in your photographs).
Corrosion resistance: 304 stainless steel provides excellent resistance to organic acids, mild chemicals, and atmospheric corrosion – suitable for food, beverage, pharmaceutical, and general industrial services.
Knowledge Module: 304 vs. 304L vs. 316L – Which Stainless Steel Flange Should You Choose?
| Material | Key Characteristic | Best Application |
|---|---|---|
| 304 | Standard 18-8 stainless – good general corrosion resistance | Non-welded components, moderate temperatures; most economical stainless option |
| 304L | Low carbon – resists intergranular corrosion after welding | Welded components where sensitization is a concern |
| 316L | Molybdenum addition – better chloride resistance | Chloride-containing environments, cooling tower water, marine atmospheres |
When to specify F304 flanges:
Service fluid is mildly corrosive or non-corrosive (water, steam, food, beverages, organic acids)
External environment is not severe (indoor, non-coastal)
Budget is a primary consideration – 304 is the most economical stainless steel
Temperature is moderate (cryogenic to ~800°C)
Knowledge Module: Flange Facing Types – Matching the Gasket to the Service
The sealing face of a flange must match the gasket type and service conditions:
| Facing Type | Abbreviation | Gasket Type | Best For |
|---|---|---|---|
| Raised Face | RF | Spiral-wound, sheet, or flat gasket | Most common – general service, moderate pressures |
| Ring-Type Joint | RTJ | Metal octagonal or oval ring | High-pressure, high-temperature services |
| Flat Face | FF | Soft sheet gasket | Low-pressure, large-diameter applications |
| Tongue & Groove | T&G | Compressed fiber or metal-jacketed | Critical services requiring positive gasket retention |
The flange shown in your photograph (machined face with bolt holes) is typically an RF (Raised Face) design – the most common facing type for heat exchanger flanges.
Knowledge Module: Flange Marking & Traceability – What the Stamping Means
The markings on your flange (as shown in the photograph) provide critical information:
| Marking | Meaning | Importance |
|---|---|---|
| ASME SA182 F304 | Material specification and grade | Confirms compliance with ASME Section II |
| OD=520mm | Outside diameter | Ensures correct flange size |
| ID=361mm | Inside diameter | Matches pipe or shell ID |
| THK=85mm | Thickness | Critical for pressure rating and bolt loading |
| HEAT NO.: 23XH03K0 | Heat number | Enables full traceability to the mill test certificate |
Advantages of Ordering Flanges from Yuhong Group
Exactly to your drawing: We machine forged blanks to your specification – OD, ID, thickness, bolt circle, and facing type.
Fast turnaround: Forged blanks in common sizes are available; machining typically 1-2 weeks.
Any material: Stainless steel (F304, F304L, F316, F316L), carbon steel (SA105, SA350 LF2), chrome-moly (F11, F22), nickel alloys.
Component-only or complete assembly: We supply just the flange – or the complete shell and tube heat exchanger with all associated components.
Full documentation: Material test certificate (MTC) per EN 10204 3.1, dimensional report, PMI test report (optional).
Component-Only Supply – We Also Provide
If you need just parts (not a full exchanger), we supply:
Heat exchanger tubes – stainless steel (304, 316L), cut to length, end-prepared for rolling or welding
Finned tube bundles – for air cooler retrofits and gas-cooling applications
U-tube bundles – complete with tubesheet, baffles, and tie rods
Heat exchanger tubesheet – drilled and grooved per your pattern
Baffles, tie rods, spacers – machined to your dimensions
Flanges – SA105, SA350 LF2, F304, F316L – any facing type
Typical Applications for F304 Flanges
| Industry | Application | Why F304 |
|---|---|---|
| Food & beverage | Piping connections, vessel flanges | Non-corrosive to food products; easy to clean |
| Pharmaceutical | Pure water systems, reactor connections | No rust; meets sanitary requirements |
| Chemical (mild) | Solvent handling, organic acids | Resists mild chemical attack |
| HVAC / district heating | Steam converters, hot water generators | Fresh water / steam service |
| Power generation | Demineralized water systems | High purity water service |
Quality Assurance & Documentation
Every F304 flange we ship includes:
Mill Test Certificate (MTC) per EN 10204 3.1 – chemical analysis and mechanical properties
Dimensional inspection report – OD, ID, thickness, bolt circle, facing dimensions
Heat number stamping – as shown on the part for full traceability
PMI (Positive Material Identification) – available on request
Third-party inspection (SGS, BV, TÜV) – at buyer's request
Get a Quotation for Your F304 Flange
To quote a stainless steel flange like the one in your photographs, send the following to jimmy@steelseamlesspipe.com:
Drawing (PDF, scan, or hand sketch with key dimensions: OD, ID, thickness, bolt circle, bolt hole size and quantity, facing type)
Or: send us your old flange for reverse engineering (return shipping arranged)
Material grade: F304 (as shown) or other
Facing type: RF, RTJ, FF, or T&G
Quantity required (single piece or production run)
We will respond with a dimensional drawing for approval, price, and delivery schedule – typically within 48 hours.
