ASME SA336 F11 CL2 Forged Channel Cover Flange

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 and covers 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 SA336 F11 CL2 channel cover flanges – a forged chrome-moly alloy component precision-machined for high-temperature heat exchanger service.

Product Focus: Channel Cover Flange – The Access Point for Tube-Side Maintenance

The channel cover flange (also called a bonnet cover or end cover flange) is a critical pressure-retaining component that closes the end of a heat exchanger channel. It provides access to the tube side for inspection, cleaning, and maintenance, while maintaining a leak-tight seal under operating pressure and temperature.

Based on the images, this flange exhibits:

• Material: ASME SA336 F11 CL2 (chrome-moly alloy steel, 1.25Cr-0.5Mo, Class 2)

• Type: Channel cover flange (管箱盖法兰)

• Dimensions: OD 630mm × ID 431.6mm × THK 100mm (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, heat number, and project number

Why SA336 F11 CL2 Chrome-Moly for Channel Cover Flanges?

Key Components That Interface with This Channel Cover Flange

Technical Highlights of Our F11 Channel Cover Flange

• Forged, not cast: Forging eliminates internal porosity and provides superior mechanical properties – essential for high-pressure containment.

• 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).

• High-temperature capability: Suitable for continuous service up to approximately 550°C (depending on pressure).

• Hydrogen service: F11 is widely specified for hydrogen-containing streams in refineries and petrochemical plants.

Knowledge Module: Channel Cover Flange vs. Tube Side Flange – Understanding the Difference

The flange shown in your photograph is a channel cover flange – it closes the end of the channel and is typically removed when tube-side inspection or maintenance is required.

Knowledge Module: F11 CL2 Material Properties & Applications

When to specify F11 CL2 for channel cover flanges:

• Operating temperature >400°C

• Operating pressure >50 bar

• Service involves hydrogen, steam, or high-temperature hydrocarbons

• ASME Code compliance required

• Carbon steel is inadequate due to creep or hydrogen attack concerns

Advantages of Ordering Channel Cover 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 1-3 weeks.

• Any material: Chrome-moly (F11, F22, F5, F91), carbon steel (SA105, SA350 LF2), stainless steel (F304, F316L), 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).

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:

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 channel covers.

Component-Only Supply – We Also Provide

If you need just parts (not a full exchanger), we supply:

• Heat exchanger tubes – chrome-moly (F11/F22), stainless steel, carbon steel – 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 & covers – SA105, SA350 LF2, F11, F22, F304, F316L – any facing type

Typical Applications for F11 Channel Cover Flanges

Quality Assurance & Documentation

Every F11 channel cover 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

• NDE – UT, MT, or PT as required

• Third-party inspection (SGS, BV, TÜV) – at buyer's request

Get a Quotation for Your F11 Channel Cover Flange

To quote a channel cover 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: F11 CL2 (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.