This reference provides the source dimensions and drafting information for a 20 inch Class 1500 blind flange. Use it when checking a piping layout, coordinating a flange connection, or locating a CAD file for detailing.
The existing data identifies the nominal size, DN designation, flange thickness, weight, stud bolt specification, bolt quantity, and hole diameter. For broader design work, compare this page with related flange dimensions, pipe schedules, piping terminology, and CAD/DWG reference resources.
Blind Flange 20″ Class 1500
Blind Flange 20″ 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 20″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 20″
- DN Size: DN500
- Flange Thickness: 177.8mm
- Weight: 1022kg
- Stud Bolt Size: 3″ UNC (or M76) x 540 Long
- Number of Bolts: 16
- Hole Diameter: 3 1/8″ (79.375mm)
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 20″ 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 20″ 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 piping or equipment connection. Unlike a flange used to connect a pipe with an open flow path, a blind flange creates a removable closure that can support isolation, inspection, maintenance, or a future connection point.
When reviewing the listed dimensions, distinguish between the nominal pipe size and the physical flange geometry. The NPS and DN entries identify the associated piping size, while thickness, weight, stud bolt details, bolt quantity, and hole diameter describe important fabrication, handling, and connection-coordination information.
Important Design Checks
- Confirm the flange material and facing requirements against the project specification.
- Verify the gasket selection and contact arrangement before installation.
- Check that the bolt or stud-bolt specification matches the approved connection details and tightening procedure.
- Confirm the applicable pressure-temperature rating for the selected material and service conditions; a class designation should not be treated as a universal allowable pressure.
- Use the DWG download for drafting coordination, then verify the drawing against the approved project documents before fabrication.
Coordination With Related Piping Data
A blind flange must be coordinated with the mating flange, gasket, bolting, equipment nozzle, and surrounding piping. Related references for flange bolt details, pipe dimensions, fittings, and piping layout can help identify interface issues, but the project specification and governing engineering review remain controlling.
Frequently Asked Questions
What is a 20 inch Class 1500 blind flange used for?
It is used to close a flanged piping, vessel, valve, or equipment connection where a solid, removable closure is required. Typical uses include isolation, maintenance shutdowns, blanking, and future expansion points.
Does a blind flange have a center bore?
No. A blind flange is a solid flange without a center bore. The source data on this page provides its connection and dimensional details for coordination with the mating flange.
What bolt information is listed for this flange?
The reference lists the stud bolt size as 3" UNC (or M76) x 540 Long, together with a bolt quantity of 16. Confirm the approved bolting system, material, thread requirements, and installation procedure before ordering.
Is the listed weight suitable for lifting planning?
The page lists a weight of 1022kg. Treat that value as reference information and confirm the actual supplied component, packaging, lifting method, and site requirements before handling.
Where can I get the CAD drawing?
The source content includes a DWG download for the 20 inch Class 1500 blind flange. Use the file for preliminary drafting and layout coordination, then check the final approved drawing and project requirements.