This reference provides the available dimension and connection data for a Blind Flange 1 1/4 Inch Class 2500. Use it when checking piping layouts, flange connections, maintenance isolation points, and drafting requirements.
The page separates the nominal pipe size from the flange details, bolt information, and CAD resource. For related design work, compare this reference with internal resources covering flange dimensions, pipe schedules, stud bolts, and piping terminology.
Blind Flange 1 1/4″ Class 2500
Blind Flange 1 1/4″ 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 1 1/4″ Class 2500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 1 1/4″
- DN Size: DN32
- Flange Thickness: 38.1mm
- Weight: 7.8kg
- Stud Bolt Size: 1″ UNC (or M27) x 150 Long
- Number of Bolts: 4
- Hole Diameter: 1 1/8″ (28.575mm)
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 1 1/4″ 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 1 1/4″ 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 Use This Blind Flange Reference
A blind flange has no center opening, so it closes a flanged connection rather than providing a passage for fluid. In a drawing or piping model, it may represent a removable closure at a pipe end, equipment nozzle, valve connection, or planned extension point.
Reading the Listed Dimensions
The nominal pipe size and DN designation identify the connection size convention. The listed flange thickness, weight, hole diameter, and bolt information support drafting, material takeoff, handling, and connection checks. Keep these values associated with the stated flange class and reference standard; do not substitute dimensions from another class or flange type.
Bolting and Installation Checks
The listed stud bolt designation includes both an inch-based UNC description and a metric alternative, together with the stated length. Confirm the project fastening practice before ordering components, especially where washers, gasket selection, facing details, corrosion allowance, or installation access affect the final assembly.
Using the CAD File
The downloadable DWG file can help with piping arrangement, equipment coordination, detailing, and preliminary layout work. CAD geometry should still be checked against the project specification and the applicable flange requirements before fabrication or installation.
Related Reference Topics
- Flange dimensions and facing terminology
- Pipe schedules and nominal pipe size conversions
- Stud bolt and flange connection terminology
- Blind flange series and matching CAD resources
Frequently Asked Questions
What is a Blind Flange 1 1/4 Inch Class 2500?
It is a solid blind flange identified for a 1 1/4-inch nominal pipe size and Class 2500 service. Its purpose is to close a flanged piping, equipment, valve, or nozzle connection.
Does a blind flange have a center bore?
No. A blind flange is a blank flange without a center bore, allowing it to provide a closure at the end of a piping system or at another flanged connection.
What bolt information is provided for this flange?
The reference lists the stud bolt size as 1-inch UNC, or M27, with a 150 mm length, along with the specified number of bolts and hole diameter. Verify the complete bolting arrangement against the project requirements before installation.
Is the listed weight suitable for lifting planning?
The page provides a reference weight for the flange. Use it for preliminary handling and material planning, then confirm the delivered component, coating, and any project-specific additions before lifting.
Can the DWG file be used for fabrication?
The DWG is provided for drafting, detailing, and piping layout coordination. Confirm dimensions, tolerances, materials, gasket requirements, and project specifications before using CAD data for fabrication.
What should be checked before purchase or installation?
Confirm the applicable standard, material specification, gasket type, bolt length, project requirements, and pressure-temperature rating. The flange class should not be treated as a substitute for a complete engineering verification.