This reference provides the dimensional and installation information for a Blind Flange 3/4 Inch Class 1500, including the flange thickness, weight, stud bolt details, bolt-hole diameter, and bolt count. Use the source values below when checking a piping layout, preparing a detail, or coordinating a replacement component.
A blind flange has no center opening, so it closes a flanged connection rather than allowing fluid to pass through. That makes it useful where a line, nozzle, valve connection, or future branch must be isolated while retaining a bolted access point for later inspection or maintenance.
Blind Flange 3/4″ Class 1500
Blind Flange 3/4″ Class 1500 is used to seal the end of a piping system or close off a flange connection in Class 1500 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 very high pressure rating is required.
This dimension data is based on ANSI / ASME B16.5-2020.
Blind Flange 3/4″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 3/4″
- DN Size: DN20
- Flange Thickness: 25.4mm
- Weight: 2.7kg
- Stud Bolt Size: 3/4″ UNC (or M20) x 115 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 1500 is commonly used for:
- Pipe end closure
- Equipment isolation
- Valve and nozzle blanking
- Maintenance shutdown work
- Process and utility piping systems
- Very high pressure piping applications
CAD Drawing Download
This page includes the CAD drawing file for Blind Flange 3/4″ Class 1500, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 1500 Sizes
This size is part of the Blind Flange Class 1500 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
Start with the nominal pipe size and pressure class shown in the source content, then compare the flange details with the mating flange, gasket, and project piping specification. The bolt pattern, hole diameter, and stud dimensions must be compatible with the connected component; dimensional compatibility should be checked before fabrication or installation.
The listed weight is useful for handling, support, and material-planning discussions, but it should not be treated as a substitute for a manufacturer’s certified product data. Actual supplied components may also be affected by material specification, facing details, tolerances, coating, and manufacturing requirements.
Drafting and CAD Coordination
The downloadable DWG can support preliminary drafting, piping arrangement work, and connection coordination. Confirm the drawing units, insertion scale, layer conventions, and project title-block requirements before incorporating it into a production drawing. CAD geometry should be checked against the authoritative dimensional data and the selected supplier’s documentation before release for fabrication.
Related Piping References
For broader design research, link this page with related references for blind flange dimensions, Class 1500 flange sizes, flange bolt dimensions, pipe schedules, gasket selection, and flange facing terminology. These related topics help readers move from a single component dimension to a complete flange-connection check.
Selection and Installation Checks
- Confirm the nominal size and pressure class match the connected piping or equipment.
- Check the flange material, gasket, facing, and bolting against the project specification.
- Verify bolt engagement, clearance, and tightening requirements with the responsible engineer or supplier.
- Use the CAD file as a drafting aid, not as independent certification of pressure-boundary performance.
- Recheck the latest project requirements before fabrication, inspection, or installation.
Blind Flange 3/4 Inch Class 1500 FAQ
What is a blind flange used for?
A blind flange closes the end of a pipe, vessel nozzle, valve connection, or other flanged opening. It provides a bolted isolation point that can be removed for maintenance or future connection work.
Does a blind flange have a center bore?
No. A blind flange is solid across its central area, unlike a flange intended to connect directly to an open pipe passage.
What information is listed for this flange?
The reference includes the nominal pipe size, DN designation, flange thickness, weight, stud bolt size and length, bolt count, and hole diameter. These values should be checked against the mating flange and project specification.
Can the listed stud bolts be used without further checking?
Not automatically. Confirm the bolting material, thread system, length, engagement, gasket thickness, flange arrangement, and tightening procedure for the actual connection before installation.
Can the DWG file be used for fabrication?
The DWG is intended to support drafting, detailing, and piping layout coordination. Verify its geometry and units against the source dimensions and approved supplier documentation before using it for fabrication.
Which standard is identified for the dimension data?
The source content identifies ANSI / ASME B16.5 as the reference standard and states that the dimension data is based on ANSI / ASME B16.5-2020. Project specifications and current applicable requirements should still be confirmed.