This reference provides a practical overview of the Blind Flange 1/2 Inch Class 300, including its source dimensions, connection details, typical uses, and CAD resource. Use the technical values on this page when checking a drawing, preparing a piping layout, or coordinating a flange connection.
A blind flange has no center opening, so its primary function is closure rather than flow passage. Before ordering or installing one, compare the flange facing, material specification, gasket arrangement, bolting, and project pressure-temperature requirements with the applicable piping documentation.
Blind Flange 1/2″ Class 300
Blind Flange 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 1/2″ Class 300 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 1/2″
- DN Size: DN15
- Flange Thickness: 12.7mm
- Weight: 1.4kg
- Stud Bolt Size: 1/2″ UNC (or M14) x 65 Long
- Number of Bolts: 4
- Hole Diameter: 5/8″ (15.875mm)
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 1/2″ 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 1/2″ 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 Use This Blind Flange Reference
The dimension list below is the page’s local reference data for this nominal size and pressure class. The NPS designation identifies the nominal pipe size, while the DN designation provides the corresponding metric naming convention. These labels describe the connection category; they are not a substitute for checking the mating flange and piping specification.
Understanding the Connection Details
Flange thickness and weight are useful for layout review, handling planning, and coordination with nearby valves, fittings, supports, and equipment. The bolt information should be read together with the bolt-hole information. A stud bolt designation describes the intended fastener, while the hole diameter describes the clearance opening through the flange. These are related but different checks.
Class 300 identifies the flange pressure-class category. It should not be treated as a single allowable working pressure for every service. The usable pressure-temperature rating depends on factors such as material, temperature, flange facing, gasket selection, bolting, and the governing project specification.
Drafting and CAD Coordination
The downloadable DWG can support preliminary drafting, piping arrangement work, and connection coordination. Confirm the drawing unit system, insertion scale, flange orientation, facing detail, and mating-component geometry before using the file for fabrication or construction documentation. CAD geometry should be checked against the dimension reference and project requirements rather than used as the sole authority.
Related Reference Topics
For broader design context, compare this page with related references for flange dimensions, pipe schedules, gasket selection, stud bolts, and piping fittings. These topics help confirm that the blind flange is compatible with the complete connection assembly.
Blind Flange 1/2 Inch Class 300 FAQ
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 can provide a removable closure for isolation, maintenance, inspection, or a possible future connection.
Does a blind flange have a center bore?
No. A blind flange is a solid flange without a center bore. Its purpose is to block the opening rather than allow fluid to pass through.
Does Class 300 specify one universal pressure?
No. The class is a standardized pressure-class designation, but the allowable pressure-temperature condition depends on the flange material and the applicable rating requirements. Verify the project specification before selection.
Are the stud bolt size and hole diameter the same measurement?
No. The stud bolt size identifies the fastener, while the hole diameter identifies the opening in the flange. Both should be checked when confirming bolting compatibility.
Can the DWG be used directly for fabrication?
The DWG is intended to support drafting and piping layout coordination. Review its units, geometry, facing information, and project-specific requirements before using it for fabrication or construction.
What should be checked before installation?
Confirm the mating flange, material specification, gasket type, bolting, facing arrangement, alignment, and applicable pressure-temperature rating. Installation should follow the project piping specification and approved engineering documents.