This reference page provides the dimensional data, bolt information, weight, and CAD resource for a Blind Flange 8 Inch Class 300. Use it when checking piping layouts, preparing fabrication drawings, or coordinating a blanked connection with valves, equipment, and pipework.
The source data below should be read together with the applicable flange standard, project specifications, material requirements, gasket selection, and pressure-temperature conditions. The listed values are the local reference data for this page; verify them against the controlled project documents before fabrication or installation.
Blind Flange 8″ Class 300
Blind Flange 8″ Class 300 is used to seal the end of a piping system or close off a flange connection in Class 300 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 8″ Class 300 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 8″
- DN Size: DN200
- Flange Thickness: 39.6mm
- Weight: 36kg
- Stud Bolt Size: 7/8″ UNC (or M24) x 140 Long
- Number of Bolts: 12
- Hole Diameter: 1″ (25.4mm)
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 8″ Class 300 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 8″ Class 300, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 300 Sizes
This size is part of the Blind Flange Class 300 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
A blind flange has no center bore, so it closes a flanged connection rather than allowing the pipe to pass through the flange. This makes it useful for isolating equipment, closing a pipe end, or providing a removable closure where access may be needed later.
Understanding the Dimension List
The dimension section identifies the nominal pipe size, metric DN designation, flange thickness, weight, bolt arrangement, and hole diameter. These fields support different parts of engineering and drafting work: the size designations help coordinate piping documents, the thickness and weight support detailing and handling reviews, and the bolt information helps check the mating flange and fastening arrangement.
Nominal pipe size is a standardized designation and should not be treated as a direct measurement of the flange outside diameter or pipe wall. For a complete connection check, compare the blind flange with the mating flange, gasket, studs or bolts, washers where specified, and the required facing details.
Bolting and Installation Checks
- Confirm that the fastener designation is compatible with the mating flange and project material requirements.
- Check that the bolt-hole pattern is aligned before tightening and that the selected fasteners provide the required engagement.
- Verify gasket type, facing condition, tightening procedure, and joint-access requirements with the project specification.
- Review clearance around the flange for tools, insulation, maintenance, and future removal.
Class Rating and Project Verification
A Class 300 designation should be reviewed with the flange material, operating temperature, fluid service, gasket, and governing design requirements. It is not a substitute for a complete pressure-temperature or piping-system assessment. Use the listed CAD file for drafting and layout coordination, then confirm critical geometry against the approved fabrication information.
Related Piping References
For broader design work, compare this page with references covering flange dimensions, pipe schedules, gasket selection, stud bolts, valve interfaces, and piping terminology. Reviewing related blind flange sizes in the same class series can also help maintain consistent connection details across a project.
Frequently Asked Questions
What is a Blind Flange 8 Inch Class 300 used for?
It is used to close a flanged piping connection, isolate equipment or a line, blank a nozzle or valve connection, and support future maintenance or extension work.
Does a blind flange have a center opening?
No. A blind flange is solid across its face and does not provide a passage for the pipe bore.
Can the CAD file be used for fabrication?
The CAD file can support drafting, detailing, and piping-layout coordination. Critical dimensions and fabrication requirements should still be checked against the approved project documents and applicable standard.
What should be checked before installation?
Confirm the mating flange, gasket, fastener specification, facing requirements, material requirements, bolt-hole alignment, clearance, and applicable pressure-temperature conditions before installation.