Designed in strict compliance with the ASME B16.5 standard (covering sizes from NPS 1/2 through NPS 24), ASME B16.5 Class 400 Blind Flange components bridge the performance gap between standard commercial Class 300 applications and severe-duty Class 600 systems. HT PIPE supply all different types and scales of flanges. Please feel free to contact us for further product information and pricing.
Why Use a Blind Flange?
System Isolation: It provides a safe, removable terminus for pressurized pipelines.
Inspection Portals: It permits uncomplicated internal inspection or cleanouts of pressure vessels and piping loops.
Structural Durability: Because it lacks an inner bore, the center of the flange bears the highest stress concentrations. To account for this, its thickness is robust enough to prevent deflection under full hydrotest or operating pressures.
Crucial Engineering Rule: The dimensional specifications for Class 400 flanges are identical to those of Class 600 flanges. Consequently, separate engineering tables for Class 400 are typically not published for these compact configurations; Class 600 components are standardly substituted.
Face Configurations and Tolerances
Raised Face (RF): Standard Class 400 blind flanges feature a 1/4-inch (7mm) raised face. This height is additional to the minimum flange thickness listed in the table above.
Ring Type Joint (RTJ): For high-temperature or extreme cyclical service, a precision-machined groove can be added to accept a metallic ring gasket. When ordering RTJ, verify the specific groove number (e.g., R-number) to ensure matching companion flanges.
What to Include in a Request for Quote (RFQ)
To eliminate delays or manufacturing errors, ensure your request specifies:
Nominal Size & Standard: (e.g., NPS 12, ASME B16.5)
Component Type: Blind Flange
Pressure Class: Class 400
Facing Profile: (e.g., 1/4" Raised Face with a 125-250 AARH smooth or serrated finish)
Material Grade: (e.g., Forged Steel ASTM A105N)
ASME B16.5 Class 400 Blind Flange Dimensions
