This reference page provides the listed dimensions, weight, bolting information, and CAD resource for a Blind Flange 1 1/2 Inch Class 300. Use the data when checking piping layouts, flange connections, equipment isolation points, and drafting details.
A blind flange has no center opening, so it closes a flanged connection rather than allowing pipe flow through the flange. The source data below should be read together with the project piping specification, gasket requirements, material requirements, and applicable pressure-temperature conditions.
Blind Flange 1 1/2″ Class 300
Blind Flange 1 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 1 1/2″ Class 300 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 1 1/2″
- DN Size: DN40
- Flange Thickness: 19mm
- Weight: 2.7kg
- Stud Bolt Size: 3/4″ UNC (or M20) x 90 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 1 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 1 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 Read the Blind Flange Reference
The listed nominal pipe size identifies the piping connection category, while the DN designation provides the corresponding metric reference. Flange thickness, bolt-hole information, bolt quantity, and stud-bolt details are used together when coordinating the flange with mating equipment or another flange.
The weight shown is a reference value for the flange item. Actual handling, shipping, and installation planning may also need to consider the selected material, gasket, fasteners, coatings, and connected components.
Class 300 and Connection Checks
The Class 300 designation identifies the flange class used by the source reference; it should not be treated as a standalone design pressure. Confirm the applicable pressure-temperature rating, flange material, facing details, gasket selection, and bolting requirements against the governing project documents before fabrication or installation.
Drafting and CAD Coordination
The downloadable DWG file can support preliminary drafting, piping layout coordination, and flange-detail development. Check the drawing against the authoritative dimension data before issuing fabrication drawings. Related internal resources may include flange dimensions, pipe schedules, flange facing types, bolting references, and the CAD/DWG piping library.
Selection and Installation Considerations
- Confirm that the blind flange matches the mating flange and project specification.
- Verify gasket compatibility and sealing-surface requirements before assembly.
- Check bolt or stud compatibility, engagement, and installation requirements with the responsible engineer or fabricator.
- For isolation or future extension work, confirm that the closure arrangement meets the system’s inspection, maintenance, and safety procedures.
Frequently Asked Questions
What is a blind flange used for?
A blind flange closes the end of a pipeline, vessel nozzle, valve connection, or other flanged opening. It is commonly used for isolation, maintenance, equipment blanking, and future connection points.
Does a blind flange have a center bore?
No. A blind flange is a solid flange without a center bore, allowing it to seal a flanged opening when installed with the required gasket and fasteners.
What information is listed for this blind flange?
The reference includes the nominal pipe size, DN designation, flange thickness, weight, stud-bolt information, bolt quantity, hole diameter, reference standard, and a CAD drawing download.
Can the DWG file be used for fabrication?
The DWG file is intended to support drafting, detailing, and piping layout coordination. Verify the drawing against the source dimensions, project specifications, and fabrication requirements before release.
What should be confirmed before installation?
Confirm the flange material, gasket type, bolting, mating connection, and applicable pressure-temperature requirements. The responsible engineer or project specification should govern final selection and installation.