This reference page brings together the published dimensions and drafting information for a Blind Flange 4 Inch Class 1500. Use it when checking a piping layout, coordinating a flange connection, or preparing fabrication and installation documentation.
The existing reference data identifies the nominal pipe size, DN designation, flange thickness, weight, stud bolt information, bolt quantity, and hole diameter. The page also includes a DWG resource for use in CAD-based piping and equipment coordination. Always compare the listed information with the project specification before releasing drawings or ordering components.
Blind Flange 4″ Class 1500
Blind Flange 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 4″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 4″
- DN Size: DN100
- Flange Thickness: 53.8mm
- Weight: 33kg
- Stud Bolt Size: 1 1/4″ UNC (or M33) x 195 Long
- Number of Bolts: 8
- Hole Diameter: 1 3/8″ (34.925mm)
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 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 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
A blind flange has no center bore. Unlike a flange intended to connect directly to an open pipe bore, it forms a solid closure over a flanged connection. This makes it useful where a line, nozzle, valve outlet, or equipment connection must be blanked off and may later need to be reopened.
For drafting work, begin by confirming the nominal size and pressure class against the connected flange or equipment nozzle. The NPS and DN designations identify the nominal connection size, but they should not be treated as a complete description of the flange. The bolt arrangement, hole diameter, facing details, gasket selection, material, and pressure-temperature requirements also affect whether components can be assembled correctly.
Dimension and Bolt-Detail Checks
- Flange thickness: Use the listed thickness for layout and dimensional review, while allowing for the applicable facing and fabrication requirements shown in the project documents.
- Weight: Treat the published weight as a handling and coordination reference. Lifting plans, supports, and installation procedures should account for the actual supplied component and site conditions.
- Stud bolts: Confirm the specified thread form, nominal size, length, material, nuts, washers, and tightening procedure as a complete bolting package. The inch and metric alternatives shown in the source should not be assumed to be interchangeable without project approval.
- Bolt holes: Check the hole diameter and bolt count against the mating flange before fabrication or field installation. Correct alignment is essential for gasket seating and safe assembly.
CAD and Internal Reference Use
The downloadable DWG can support piping layouts, nozzle coordination, general arrangement drawings, and detail development. A CAD file should be used as a drafting aid rather than as a substitute for the controlled dimensional data, purchase specification, or certified manufacturer documentation.
For related research, link this page to the site’s flange dimensions references, pipe schedules, gasket references, stud bolt and nut guides, and piping terminology pages. These connections help readers move from a component dimension check to the surrounding design and installation requirements.
Selection and Verification Notes
The Class 1500 designation identifies the flange class used by the applicable standard system; it is not, by itself, a universal allowable pressure for every service. The actual pressure-temperature capability depends on factors such as material, temperature, facing, gasket, bolting, and the governing project requirements. Verify those details before selecting the component for service.
Frequently Asked Questions
What is a blind flange used for?
A blind flange closes the end of a piping system, vessel nozzle, valve connection, or other flanged outlet. It can provide a removable closure for isolation, maintenance, inspection, or a future connection.
Does a blind flange have a center bore?
No. A blind flange is solid across its center and is designed to block the connected opening rather than pass fluid through the flange.
What information is listed for this Blind Flange 4 Inch Class 1500?
The source data lists the nominal pipe size, DN designation, flange thickness, weight, stud bolt size and length, number of bolts, and hole diameter. It also identifies the applicable reference standard and provides a CAD drawing download.
Can the DWG file be used for fabrication?
The DWG is intended to support drafting, detailing, and piping layout coordination. Before fabrication, compare the drawing with the controlled dimension data, purchase requirements, material specification, gasket requirements, and the manufacturer’s documentation.
Are the inch and metric stud bolt descriptions automatically interchangeable?
No. The source presents inch and metric descriptions as alternatives, but thread compatibility, nuts, material, length, and project requirements must be verified before substitution.
What should be checked before installation?
Confirm the mating flange, bolt-hole alignment, gasket type, flange facing, bolting package, material specification, and applicable pressure-temperature requirements. Installation should follow the approved project procedure and the responsible engineer’s direction.