This reference page provides the listed dimensions, weight, stud bolt information, and CAD resource for a Blind Flange 2 1/2 Inch Class 300. Use the source data for preliminary piping layouts, flange identification, drafting, and coordination, then verify the project specification before fabrication or installation.
A blind flange has no center bore, so its primary function is to close a flanged connection or terminate a piping branch. It can also provide an access point for future work, provided the isolation and pressure-control requirements are addressed by the responsible engineering team.
For related design work, compare this reference with pages covering flange dimensions, pipe schedules, gasket selection, stud bolts, and piping CAD/DWG resources. These related references help connect the flange data to the rest of a piping assembly.
Blind Flange 2 1/2″ Class 300
Blind Flange 2 1/2″ 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 2 1/2″ Class 300 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 2 1/2″
- DN Size: DN65
- Flange Thickness: 23.9mm
- Weight: 5.5kg
- Stud Bolt Size: 3/4″ UNC (or M20) x 100 Long
- Number of Bolts: 8
- Hole Diameter: 7/8″ (22.225mm)
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 2 1/2″ 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 2 1/2″ 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
The existing data identifies the nominal pipe size, DN designation, flange thickness, listed weight, stud bolt description, bolt quantity, and hole diameter. Treat these as coordinated reference items: the flange size must match the connected piping and equipment, while the bolt pattern, gasket arrangement, and facing details must match the mating flange.
Understanding the Bolt Information
The source lists both the stud bolt designation and the hole diameter. These are related but different items. The stud bolt description identifies the threaded fastener and its stated length; the hole diameter describes the clearance opening through the flange. Do not substitute a different thread system, fastener length, washer arrangement, or tightening procedure without checking the applicable project requirements.
Class Designation and Verification
Class 300 identifies the flange class used for specification and selection. It should not be treated as a standalone allowable pressure for every service condition. Final suitability depends on the applicable pressure-temperature limits, material specification, gasket, bolting, facing, fluid service, and governing project requirements.
CAD and Drafting Workflow
The downloadable DWG can support layout development, detailing, and coordination. Before using it as a fabrication or construction reference, confirm units, insertion point, layer practices, mating dimensions, gasket space, bolt access, and any project-specific CAD standards. A drawing file does not replace dimensional verification against the applicable flange standard and approved project documents.
Practical Coordination Checklist
- Confirm the nominal pipe size and DN designation match the connected component.
- Check the flange class and material against the piping specification.
- Coordinate the bolt pattern and hole information with the mating flange.
- Confirm gasket type, facing, and contact surfaces before assembly.
- Review the listed weight when planning handling or support coordination.
- Verify isolation, inspection, and pressure-control requirements before removal or installation.
For broader reference work, useful internal links include Class 300 flange dimensions, blind flange CAD drawings, pipe flange terminology, and piping drafting guidelines.
Frequently Asked Questions
What is a Blind Flange 2 1/2 Inch Class 300 used for?
It is used to close the end of a piping system, vessel nozzle, equipment connection, or other flanged opening. Typical uses include isolation, maintenance work, valve or nozzle blanking, and planned future connections.
Does a blind flange have a center bore?
No. A blind flange is a solid flange without a center bore. Its blank face closes the connected opening when installed with the required gasket and bolting arrangement.
What bolt information is listed for this flange?
The source data lists a 3/4 inch UNC or M20 stud bolt designation, a stated length, a bolt quantity, and a hole diameter. Confirm the required fastener system and assembly details against the project specification before ordering.
Can the DWG file be used directly for fabrication?
The DWG is intended to support drafting, detailing, and piping layout coordination. It should be checked against the applicable standard, approved drawings, units, mating components, and project requirements before fabrication.
Is Class 300 the same as a fixed pressure value?
No. The class designation is part of the flange specification and does not by itself establish an allowable pressure for every material, temperature, or service condition. Use the applicable rating information and engineering review for final selection.