This reference provides the dimensional data, fastener information, weight, applications, and CAD resource for a 2 1/2-inch Class 150 blind flange. Use the listed values when reviewing piping layouts, flange connections, fabrication details, and equipment isolation arrangements.
A blind flange has no center opening, so its primary function is to close a flanged connection rather than connect two pipe bores. The source data below identifies the nominal size in both NPS and DN terms and lists the flange, bolt, and bolt-hole information for drafting and coordination.
Blind Flange 2 1/2″ Class 150
Blind Flange 2 1/2″ Class 150 is used to seal the end of a piping system or close off a flange connection in Class 150 service. It is a solid flange without a center bore and is commonly applied in industrial piping, maintenance isolation points, and future line expansion connections.
This dimension data is based on ANSI / ASME B16.5.
Blind Flange 2 1/2″ Class 150 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 2 1/2″
- DN Size: DN65
- Flange Thickness: 20.6mm
- Weight: 3.2kg
- Stud Bolt Size: 5/8″ UNC (or M16) x 90 Long
- Number of Bolts: 4
- Hole Diameter: 3/4″ (19.05mm)
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 150 is commonly used for:
- Pipe end closure
- Equipment isolation
- Valve and nozzle blanking
- Maintenance shutdown work
- Process and utility piping systems
CAD Drawing Download
This page includes the CAD drawing file for Blind Flange 2 1/2″ Class 150, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 150 Sizes
This size is part of the Blind Flange Class 150 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 This Blind Flange Reference
The dimension list separates the flange identification from the connection details. NPS identifies the nominal pipe size used in U.S. piping practice, while DN provides the corresponding metric designation. These labels describe the nominal connection size and should not be treated as a direct measurement of every flange feature.
Flange thickness, bolt-hole diameter, bolt quantity, and stud bolt designation are especially important when checking a general arrangement, equipment nozzle connection, or piping fabrication detail. The bolt designation shown in the source gives an inch-based UNC option and a metric option. These alternatives should be coordinated with the project specification, mating flange, gasket arrangement, and approved bolting requirements rather than assumed to be interchangeable.
Using the CAD Drawing
The downloadable DWG file can support preliminary drafting, piping layout coordination, and detail development. Before the drawing is released for fabrication or construction, verify the mating flange, facing requirements, gasket selection, bolting arrangement, material specification, and project design basis. A CAD representation should be checked against the applicable project documents and does not replace engineering review.
Related Reference Topics
This page can be used alongside related references for flange dimensions, pipe schedules, flange types, bolting terminology, gasket selection, and CAD piping details. Comparing entries within the Class 150 blind flange series can help maintain consistent connection information across a piping model or drawing set.
Frequently Asked Questions
What is a 2 1/2-inch Class 150 blind flange used for?
It is used to close the end of a piping system or blank a flanged connection. Typical uses listed for this reference include pipe end closure, equipment isolation, valve and nozzle blanking, maintenance shutdown work, and process or utility piping.
Does a blind flange have a center bore?
No. A blind flange is a solid flange without a center bore. It closes the connection instead of allowing fluid to pass through to another pipe section.
What bolt information is listed for this flange?
The source lists a 5/8-inch UNC stud bolt designation, or an M16 alternative, with the specified length. It also lists the bolt quantity and hole diameter. Confirm the final bolting arrangement against the project specification and the mating flange.
Can the DWG file be used directly for fabrication?
The DWG file is intended to support drafting, detailing, and piping layout coordination. Fabrication use requires verification of the applicable dimensions, materials, gasket, bolting, mating connection, and project requirements.
What should be checked before installation?
Confirm the latest project requirements, flange material specification, gasket type, bolt length, and applicable pressure-temperature rating before fabrication or installation.