This reference page provides the source dimensions and connection details for a Blind Flange 1 1/2 Inch Class 400. Use it when checking a piping layout, reviewing a flange connection, or coordinating a CAD detail. The flange closes a line or equipment connection without providing a through-flow path, so selection should be reviewed together with the mating flange, gasket, bolting, material specification, and pressure-temperature requirements.
For related design work, compare this page with the site’s references for flange dimensions, pipe schedules, gasket selection, stud bolts, and piping isometric drawings. Those references help place the listed flange data in the wider piping-documentation workflow.
Blind Flange 1 1/2″ Class 400
Blind Flange 1 1/2″ Class 400 is used to seal the end of a piping system or close off a flange connection in Class 400 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 1/2″ Class 400 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 1 1/2″
- DN Size: DN40
- Flange Thickness: 22.4mm
- Weight: 3.7kg
- Stud Bolt Size: 3/4″ UNC (or M20) x 110 Long
- Number of Bolts: 4
- Hole Diameter: 7/8″ (22.225mm)
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 1/2″ Class 400 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 1/2″ Class 400, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 400 Sizes
This size is part of the Blind Flange Class 400 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 existing data identifies the nominal pipe size, DN designation, flange thickness, weight, stud bolt information, bolt count, and hole diameter. Treat these values as a coordinated set when preparing a piping detail. A flange connection must match the adjoining flange arrangement and the project’s selected gasket and bolting system; a single dimension should not be used in isolation.
Reading the connection information
The NPS and DN entries identify the nominal size of the connection. The flange thickness and weight are useful for detailing, material takeoff, handling review, and CAD coordination. The listed stud bolt size, length, and hole diameter should be checked against the project’s bolting practice and the mating component before procurement or installation.
Blind flange and isolation work
Because a blind flange is solid, it is used where the piping route or equipment connection must be closed rather than continued through the flange. Typical review points include maintenance isolation, temporary or permanent blanking, a future connection point, and access to a valve or nozzle arrangement. Actual use requires confirmation of the applicable pressure-temperature rating, flange material, gasket, facing, and project requirements.
Using the CAD drawing
The downloadable DWG can support drafting, piping layout coordination, and detailing. Before using it for fabrication, compare the drawing with the project specification and the mating flange information. Confirm units, drawing orientation, revision status, facing details, and any requirements that are not represented in the CAD file.
Related piping references
- Flange dimension references: useful for comparing mating flange details.
- Pipe and fitting references: useful for checking how the blind flange fits into a larger piping arrangement.
- CAD and DWG resources: useful for layout coordination and drafting workflows.
- Piping terminology guides: useful when interpreting NPS, DN, bolting, gasket, and isolation terminology.
Frequently Asked Questions
What is a Blind Flange 1 1/2 Inch Class 400 used for?
It is used to close a piping end, equipment nozzle, valve connection, or other flanged opening where a solid closure is required. It may also support maintenance isolation or a future connection arrangement.
Does a blind flange have a center bore?
No. A blind flange is solid across the flow opening. It closes the connected system rather than allowing fluid to pass through the flange.
Does Class 400 alone determine allowable pressure?
No. The applicable pressure-temperature rating depends on the governing standard, material, temperature, and project requirements. Confirm the complete rating basis before selection or installation.
What should be checked before ordering this flange?
Check the mating flange, flange material, gasket type, bolt system and length, facing details, pressure-temperature requirements, and any project-specific fabrication or installation instructions.
Can the downloadable DWG be used for fabrication?
The DWG is intended to support drafting, detailing, and piping layout coordination. Use it as a reference and verify it against the project specification, current design documents, and the mating components before fabrication.