This reference page brings together the published dimensional information for a Blind Flange 18 Inch Class 1500, including its thickness, weight, bolting details, and hole diameter. Use the source values for drafting and procurement review, then confirm the complete project specification before fabrication or installation.
For related design work, compare this page with the site’s references for flange dimensions, pipe schedules, stud bolts, gasket selection, and CAD/DWG piping details. These related topics help connect the flange data to the larger piping assembly without treating one component’s dimensions as a complete design approval.
Blind Flange 18″ Class 1500
Blind Flange 18″ 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 18″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 18″
- DN Size: DN450
- Flange Thickness: 162.1mm
- Weight: 795kg
- Stud Bolt Size: 2 3/4″ UNC (or M72) x 495 Long
- Number of Bolts: 16
- Hole Diameter: 2 7/8″ (73.025mm)
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 18″ 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 18″ 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
A blind flange has no center bore, so its primary function is to close a flanged connection or pipe end. In a drawing, it is typically reviewed together with the mating flange, gasket, fasteners, and the adjoining pipe or equipment nozzle. The listed bolt count, stud size, and hole diameter should therefore be checked against the mating connection and the project’s procurement requirements.
Dimensions, Weight, and Bolting
The source section provides the dimensional and mass information for the 18-inch Class 1500 item. The flange thickness and weight support layout, handling, and material review, while the stud bolt information identifies the bolting arrangement presented by the reference. Hole diameter and bolt count are especially important when coordinating a blind flange with an existing flange face or a fabrication drawing.
Pressure Class Is Not a Standalone Design Check
Class 1500 identifies the flange class used by the reference; it should not be treated as a complete substitute for a pressure-temperature review. Actual use depends on the applicable standard, material specification, temperature, gasket, bolting, joint condition, and project requirements. Confirm the allowable rating and assembly requirements with the responsible engineer or specification before release.
Drafting and CAD Coordination
The downloadable DWG can help with piping layout, equipment connection coordination, and fabrication detailing. Before issuing a drawing, check the flange orientation, mating face, bolt-hole alignment, gasket location, and clearance for tools or maintenance. The CAD file should be used alongside the published dimension list and verified against the project’s controlled design documents.
Procurement and Installation Review
- Confirm the nominal size and flange class against the line list or equipment connection.
- Verify material, facing, gasket, and bolting requirements against the project specification.
- Check the mating flange and bolt-hole pattern before ordering or fabrication.
- Review pressure-temperature requirements rather than relying on the class designation alone.
- Confirm the latest approved drawings and applicable standard requirements before installation.
Frequently Asked Questions
What is the purpose of a blind flange?
A blind flange closes a pipe end, vessel nozzle, valve connection, or other flanged opening. It can provide a removable closure for isolation, inspection, maintenance, or a future connection, subject to the project design and safety procedure.
Does a blind flange have a center bore?
No. A blind flange is a solid flange without a center bore. Its sealing performance depends on the flange face, gasket, bolting, material, and correct assembly.
What information is listed for the 18-inch Class 1500 flange?
The source provides the nominal size, DN designation, flange thickness, weight, stud bolt size and length, number of bolts, and hole diameter. Treat those values as the local reference data for this page and confirm them against controlled project documentation before use.
Can the DWG be used directly for fabrication?
The DWG is intended to support drafting, detailing, and piping layout coordination. It should not be treated as a substitute for fabrication drawings, material requirements, inspection criteria, or engineering approval.
Does Class 1500 alone determine the allowable pressure?
No. The applicable pressure-temperature rating depends on the governing requirements and factors such as material, temperature, gasket, bolting, and joint conditions. A qualified reviewer should confirm the rating for the intended service.
What should be checked before installation?
Confirm the mating flange, face and gasket requirements, bolt-hole alignment, fastener specification, material documentation, approved drawings, and the applicable installation procedure. Also verify that the connection has been safely isolated before work begins.