ASTM A694 F65 Blind Flange | ASME B16.5 RF & RTJ

ASTM A694 F65 Blind Flanges are high-yield forged steel flanges used to close pipeline ends, valve connections, pressure equipment nozzles and future piping tie-in points in high-pressure transmission systems.

Grade F65 provides a minimum yield strength of 65 ksi / 450 MPa, making it suitable for high-strength oil and gas pipeline applications, including systems using API 5L X65 line pipe.

F65 blind flanges can be supplied to ASME B16.5 with Raised Face (RF) or Ring Type Joint (RTJ) facings. NACE sour-service requirements, HIC testing, Charpy impact testing and third-party inspection can be provided when specified by the project.

ASTM A694 F65 Blind Flange Overview

What Is ASTM A694 F65?

ASTM A694 covers carbon and alloy steel forgings for pipe flanges, fittings, valves and other components intended for high-pressure transmission service.

Grade F65 is identified primarily by its 65 ksi minimum yield strength.

Unlike a single fixed alloy designation, F65 can be produced from suitable carbon steel, high-strength low-alloy steel or alloy steel chemistry capable of achieving the required properties after heat treatment.

Typical mechanical requirements include:

Impact testing is not automatically required for every ASTM A694 F65 flange and should be specified separately where required by the project design temperature or piping specification.

ASME B16.5 F65 Blind Flanges

ASTM A694 defines the flange material requirements, while ASME B16.5 defines dimensions, pressure classes, facings and dimensional tolerances.

ASME B16.5 covers flange sizes from NPS 1/2 through NPS 24, subject to the applicable pressure-class and size combination.

Common pressure classes include:

• Class 150
• Class 300
• Class 400
• Class 600
• Class 900
• Class 1500
• Class 2500

Unlike a Weld Neck flange, a standard blind flange has no pipe bore. A pipe schedule such as Sch 80 or Sch 160 is therefore normally not required when ordering a conventional blind flange.

ASTM A694 F65 RF Blind Flange

F65 Raised Face Blind Flanges are widely used for pipeline termination, valve isolation and pressure-system closure.

Typical applications include:

• Pipeline end closures
• Valve connections
• Manifold systems
• Pressure vessel nozzles
• Hydrotest connections
• Future piping tie-ins

Typical order description:

ASTM A694 F65 Blind Flange, NPS 12″, Class 600, RF, ASME B16.5

ASTM A694 F65 RTJ Blind Flange

F65 RTJ Blind Flanges are commonly selected for higher-pressure flange connections using metallic Ring Type Joint gaskets.

Typical applications include:

• High-pressure oil and gas pipelines
• Compressor stations
• Offshore piping
• Manifolds
• High-pressure process systems
• Critical isolation points

Typical order:

ASTM A694 F65 Blind Flange, NPS 8″, Class 1500, RTJ, ASME B16.5

The RTJ groove must correspond to the mating flange and specified ring gasket.

For critical service, additional groove dimensional and surface inspection can be specified.

F65 Blind Flanges for API 5L X65 Pipeline Systems

ASTM A694 F65 is commonly used as the flange material in high-yield pipeline systems together with API 5L X65 pipe and ASTM A860 WPHY65 fittings.

These grades provide compatible high-yield-strength levels for many transmission-pipeline applications.

However, API 5L X65, ASTM A694 F65 and ASTM A860 WPHY65 are different product specifications and are not directly interchangeable material grades.

Each product must meet its own applicable specification and project requirements.

NACE Sour-Service F65 Blind Flanges

ASTM A694 F65 Blind Flanges can be supplied for projects specifying NACE MR0175 / ISO 15156 requirements.

Sour-service suitability is project specific and may require control of:

• Material chemistry
• Heat-treatment condition
• Hardness
• Manufacturing condition
• H₂S exposure
• Service environment

ASTM A694 F65 designation alone does not automatically establish NACE compliance.

HIC Tested A694 F65 Blind Flanges

Hydrogen-Induced Cracking testing can be performed to NACE TM0284 when specified.

HIC testing is an additional purchaser or project requirement and is not a mandatory requirement of ASTM A694.

The required test conditions and acceptance criteria should be stated in the project specification.

Inspection and Certification

Available inspection and documentation include:

• EN 10204 Type 3.1 MTC
• EN 10204 Type 3.2 when specified
• Chemical Analysis
• Mechanical Testing
• Hardness Testing
• Charpy Impact Testing when specified
• Ultrasonic Testing
• Magnetic Particle Testing
• HIC Testing when specified
• Dimensional Inspection
• RTJ Groove Inspection
• Third-Party Inspection

Related ASTM A694 F65 Flanges

ASTM A694 F65 is available in different flange configurations for high-pressure pipeline and transmission-service applications.

ASTM A694 F65 Weld Neck Flange

ASTM A694 F65 Weld Neck Flanges are available in WNRF and WNRTJ configurations for welded high-pressure pipeline connections.

Weld Neck flanges are commonly selected where the flange is directly butt welded to the pipe and good stress distribution through the tapered hub is required.

ASTM A694 F65 Slip-On Flange

A694 F65 Slip-On Flanges can be supplied where slip-on construction is permitted by the applicable piping specification.

They are normally used in less demanding flange connections than Weld Neck configurations and should be selected according to the applicable piping class and design requirements.

ASTM A694 F65 RTJ Flanges

Ring Type Joint facings are available on both Weld Neck and Blind Flanges for high-pressure applications requiring metallic ring gaskets.

Typical configurations include:

• F65 WNRTJ Flange
• F65 RTJ Blind Flange
• Class 600 RTJ
• Class 900 RTJ
• Class 1500 RTJ
• Class 2500 RTJ where applicable

Flange type, pressure class and facing should always be specified separately.

How to Order ASTM A694 F65 Blind Flanges

A complete RFQ should include:

• ASTM A694 F65
• Blind Flange
• Nominal Pipe Size
• Pressure Class
• RF or RTJ
• ASME B16.5
• Quantity
• Sour-service requirement if applicable
• HIC or impact testing if required
• Certification and inspection requirements

Example

ASTM A694 F65 Blind Flange, NPS 10″, Class 1500, RTJ, ASME B16.5, NACE MR0175 / ISO 15156 and HIC testing as specified

Frequently Asked Questions

What is an ASTM A694 F65 Blind Flange?

It is a high-yield forged steel blind flange used to close high-pressure pipeline and piping-system connections.

What is the difference between F65 RF and RTJ Blind Flanges?

RF blind flanges use a conventional gasket on the raised-face seating area, while RTJ blind flanges use a metallic ring gasket installed in a machined ring groove.

Does an F65 Blind Flange require a pipe schedule?

A conventional blind flange has no pipe bore, so pipe schedule is normally not required.

Can ASTM A694 F65 be used with API 5L X65 pipe?

ASTM A694 F65 flanges are commonly used in pipeline systems containing API 5L X65 pipe, but F65 and X65 are separate product specifications and should not be described as directly equivalent.

Can A694 F65 Blind Flanges be HIC tested?

Yes. HIC testing can be performed to NACE TM0284 when specifically required by the project.

ASTM A694 F65 Blind Flange ASME B16.5

ASTM A694 F65 Blind Flange Manufacturer and Supplier

We manufacture and supply ASTM A694 F65 Blind Flanges for high-pressure pipeline, oil and gas, offshore and process-piping applications.

Available products include RF and RTJ Blind Flanges to ASME B16.5, together with ASTM A694 F65 Weld Neck and other project-specified flange configurations.

Project-specific NACE, HIC, impact testing, NDE and third-party inspection can be provided when required.