This reference page covers the dimensional and connection details for a Blind Flange 12 Inch Class 600. Use the source data when checking flange thickness, bolt arrangement, hole diameter, weight, and stud-bolt information for drafting or piping coordination.
A blind flange has no center opening, so it closes a flanged connection rather than joining two open pipe bores. For related design work, compare this page with the site’s references for flange dimensions, pipe schedules, gaskets, stud bolts, and CAD/DWG piping details.
Blind Flange 12″ Class 600
Blind Flange 12″ Class 600 is used to seal the end of a piping system or close off a flange connection in Class 600 service. It is a solid flange without a center bore and is commonly used in industrial piping systems, maintenance isolation points, and future pipeline expansion connections where a higher pressure rating is required.
This dimension data is based on ANSI / ASME B16.5-2020.
Blind Flange 12″ Class 600 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 12″
- DN Size: DN300
- Flange Thickness: 66.5mm
- Weight: 134kg
- Stud Bolt Size: 1 1/4″ UNC (or M33) x 220 Long
- Number of Bolts: 20
- Hole Diameter: 1 3/8″ (34.925mm)
What Is a Blind Flange?
A blind flange is a blank flange used to close the end of a pipeline, vessel nozzle, or equipment connection. It provides a secure shutoff point and is often selected when future maintenance, inspection, or line extension may be required.
Common Applications
Blind Flange 12″ Class 600 is commonly used for:
- Pipe end closure
- Equipment isolation
- Valve and nozzle blanking
- Maintenance shutdown work
- Process and utility piping systems
- Higher pressure piping applications
CAD Drawing Download
This page includes the CAD drawing file for Blind Flange 12″ Class 600, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 600 Sizes
This size is part of the Blind Flange Class 600 series. Check other sizes in the same category to find matching dimension data and CAD files for your project.
Notes
Before fabrication or installation, always confirm the latest project requirements, flange material specification, gasket type, bolt length, and applicable pressure-temperature rating.
How to Use This Blind Flange Reference
The dimensional list identifies the nominal pipe size, DN designation, flange thickness, weight, stud-bolt specification, bolt quantity, and hole diameter. These items support preliminary layout, fabrication review, material takeoff, and drawing coordination. They should be checked against the project’s approved specifications before fabrication or installation.
Understanding the Size Designations
NPS and DN are nominal size designations used to identify the associated piping size. They are reference identifiers rather than a complete description of every mating component. When coordinating a blind flange with pipe, valves, fittings, or equipment, confirm that the mating flange standard and facing details match.
Bolting and Connection Checks
The listed stud-bolt size, length, bolt count, and hole diameter are important for connection detailing. Confirm the project’s bolting material, thread requirements, washer practice, tightening procedure, and required bolt projection separately. Bolt length can also depend on the flange arrangement, gasket, washers, and mating component, so the listed value should not be treated as a universal installation rule.
CAD and Drafting Use
The downloadable DWG can help with drafting, piping layout coordination, and equipment-connection studies. Before issuing a drawing, verify the flange orientation, mating face, gasket envelope, clearances, and any site-specific modeling requirements. Related internal references for flange CAD blocks, piping fittings, and flange terminology can help maintain consistent project documentation.
Selection and Verification
Class designation alone does not replace a pressure-temperature, material, gasket, and bolting review. Confirm the applicable project standard, material specification, service conditions, and inspection requirements. The local dimension list remains the controlling reference for the values published on this page.
Frequently Asked Questions
What is a 12-inch Class 600 blind flange used for?
It is used to close a piping, vessel, valve, nozzle, or equipment connection where a solid flange is required. Typical uses include isolation, maintenance work, blanking, and future line modifications.
Does a blind flange have a center bore?
No. A blind flange is solid across the central area and is designed to seal the end of a flanged connection.
What bolt information is provided for this flange?
The reference data provides the stud-bolt size and length, the number of bolts, and the hole diameter. Confirm the complete bolting arrangement with the mating flange and project requirements.
Can the DWG be used directly for fabrication?
The DWG is intended to support drafting, detailing, and layout coordination. Fabrication should proceed only after the drawing, material specification, gasket selection, bolting, and applicable project requirements have been reviewed and approved.
Is the Class 600 designation sufficient for selection?
No. Selection also requires a review of material, service conditions, pressure-temperature requirements, gasket type, bolting, and the applicable project specification.