This reference provides the dimensional and identification data for a Blind Flange 1 Inch Class 900, including its listed thickness, weight, stud bolt information, bolt count, and hole diameter. Use the source values on this page when checking a drawing, preparing a piping layout, or coordinating a matching flange connection.
A blind flange closes a piping or equipment connection without providing a flow passage. Its removable bolted connection can support isolation, maintenance access, equipment blanking, and future connection work, subject to the project design and applicable engineering review.
Blind Flange 1″ Class 900
Blind Flange 1″ Class 900 is used to seal the end of a piping system or close off a flange connection in Class 900 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″ Class 900 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 1″
- DN Size: DN25
- Flange Thickness: 28.6mm
- Weight: 3.6kg
- Stud Bolt Size: 7/8″ UNC (or M24) x 125 Long
- Number of Bolts: 4
- Hole Diameter: 1″ (25.4mm)
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″ Class 900 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″ Class 900, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 900 Sizes
This size is part of the Blind Flange Class 900 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
The dimension list identifies the nominal pipe size, DN designation, flange thickness, weight, fastening details, and reference standard for this flange. These fields are useful when comparing the component with a piping specification, an equipment nozzle, a mating flange, or a CAD layout.
When reviewing the bolt information, check that the selected studs, nuts, washers, and tightening procedure match the project requirements. The mating flange must also have a compatible bolt pattern, facing arrangement, gasket selection, and material specification. Do not treat the flange class designation alone as a complete pressure-temperature design check.
Drafting and CAD Coordination
The downloadable DWG file can help with piping arrangement, equipment connection details, and fabrication drafting. Before issuing a drawing, confirm the flange orientation, bolt-hole alignment, gasket position, clearance for tools, and access needed for removal. CAD geometry should be checked against the listed reference data and the current project specification.
Related Piping References
For broader design and drafting work, this page can be used alongside references for flange dimensions, pipe schedules, flange facing types, gasket selection, and stud bolt terminology. Related Blind Flange Class 900 size pages can help with comparison when selecting a different nominal pipe size.
Frequently Asked Questions
What is a Blind Flange 1 Inch Class 900 used for?
It is used to close a pipe end, equipment nozzle, valve connection, or other flanged opening. Typical uses include isolation, maintenance shutdown work, blanking, and provision for future piping changes.
Does a blind flange have a center bore?
No. A blind flange is a solid flange intended to stop flow through the connection rather than pass a pipe through its center.
What should be checked before ordering this flange?
Confirm the nominal size, flange class, reference standard, material specification, facing and gasket requirements, stud bolt details, bolt-hole compatibility, and project pressure-temperature requirements.
Can the DWG file be used directly for fabrication?
The DWG is useful for drafting and coordination, but fabrication documents should be checked against the listed dimensions, project specifications, material requirements, and the applicable engineering review process.
How do I find another size in this flange series?
Use the related Blind Flange Class 900 size references on the site to compare corresponding dimension data and available CAD files.