This reference provides the published dimensions and identification details for a Blind Flange 3/4 Inch Class 2500. Use the dimensional information below when checking piping layouts, flange connections, fabrication details, and CAD models.
A blind flange has no center opening, so it closes a flanged connection rather than providing a passage for fluid. The listed NPS and DN identifiers help match the flange to piping documentation, while the bolt information supports connection detailing and coordination with the mating flange.
Blind Flange 3/4″ Class 2500
Blind Flange 3/4″ Class 2500 is used to seal the end of a piping system or close off a flange connection in Class 2500 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 an extremely high pressure rating is required.
This dimension data is based on ANSI / ASME B16.5-2020.
Blind Flange 3/4″ Class 2500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 3/4″
- DN Size: DN20
- Flange Thickness: 31.8mm
- Weight: 3.7kg
- Stud Bolt Size: 3/4″ UNC (or M20) x 125 Long
- Number of Bolts: 4
- 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 3/4″ Class 2500 is commonly used for:
- Pipe end closure
- Equipment isolation
- Valve and nozzle blanking
- Maintenance shutdown work
- Process and utility piping systems
- Extremely high pressure piping applications
CAD Drawing Download
This page includes the CAD drawing file for Blind Flange 3/4″ Class 2500, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 2500 Sizes
This size is part of the Blind Flange Class 2500 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 Read the Blind Flange Reference
The existing reference list separates the main identification, dimensional, and fastening information. The flange thickness and weight are useful for fabrication review, handling planning, and model coordination. The stud bolt size, bolt count, and hole diameter should be checked together because all three affect the bolted joint arrangement.
The listed stud length should not be treated as a substitute for a project-specific bolting check. Actual required length can depend on the mating flange, gasket, washers, nuts, coating, and the amount of thread engagement required by the project. Confirm the complete joint stack-up before procurement or installation.
Nominal Size and Connection Coordination
NPS and DN identify the nominal pipe size system; they are not interchangeable with a direct measurement of every flange feature. When coordinating this flange with pipe, valves, equipment nozzles, or fittings, compare the complete connection details rather than relying on the nominal size alone. Related references for flange dimensions, pipe schedules, flange facing, and stud bolt terminology can help resolve those coordination checks.
Using the CAD Drawing
The downloadable DWG is intended to support drafting, piping layout, and detail coordination. Treat the drawing as a reference for the published flange geometry and confirm that the selected model matches the project material, facing, gasket, bolting, and revision requirements before it is used for fabrication.
Selection and Installation Checks
- Confirm that the flange class and project pressure-temperature requirements are compatible.
- Verify the flange material and any required material certification.
- Match the gasket and facing arrangement to the mating connection.
- Check bolt-hole alignment, stud length, washers, nuts, and required thread engagement.
- Confirm that the blind flange is appropriate for the intended isolation, testing, or future connection work.
These checks support engineering review but do not replace the project piping specification, applicable design calculations, or the responsible engineer’s approval.
Frequently Asked Questions
What does a blind flange do?
A blind flange closes the end of a pipe, equipment nozzle, valve connection, or other flanged opening. Because it has no center bore, it blocks the normal flow path at that connection.
What does 3/4 inch Class 2500 identify?
The size identifies the nominal connection size, while the class identifies the flange pressure-temperature classification system used for selection. The applicable rating must still be confirmed against the material, temperature, design conditions, and project requirements.
Are the stud bolt size and hole diameter the same thing?
No. The stud bolt size describes the fastener, while the hole diameter describes the clearance opening through the flange. Both details are needed to coordinate the bolted connection.
Can the listed bolt length be used for every installation?
No. The listed length is a reference for this flange entry. Final bolt selection should account for the mating flange, gasket, washers, nuts, coatings, and required thread engagement.
What should be checked before using the CAD file?
Confirm the drawing revision, flange dimensions, mating components, facing, material, gasket arrangement, and project-specific requirements. CAD geometry should be reviewed before fabrication or release for construction.
Where can I find related piping information?
Use related references for Class 2500 blind flanges, flange bolt dimensions, pipe flange terminology, and DWG piping details to compare connection components and improve layout coordination.