This reference covers the dimensions and connection details for a Blind Flange 4 Inch Class 150. Use it to check the listed flange thickness, weight, bolt arrangement, hole diameter, and stud bolt specification before preparing piping drawings or fabrication documents.
A blind flange has no center bore, so it closes a flanged pipe, nozzle, valve connection, or equipment opening. The page also includes a DWG resource for drafting and layout coordination. Treat the published dimensional data as the controlling local reference, then confirm project requirements before ordering or installation.
Blind Flange 4″ Class 150
Blind Flange 4″ Class 150 is used to seal the end of a piping system or close off a flange connection in Class 150 service. It is a solid flange without a center bore and is commonly applied in industrial piping, maintenance isolation points, and future line expansion connections.
This dimension data is based on ANSI / ASME B16.5.
Blind Flange 4″ Class 150 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS): 4″
- DN Size: DN100
- Flange Thickness: 22.4mm
- Weight: 7.7kg
- Stud Bolt Size: 5/8″ UNC (or M16) x 90 Long
- Number of Bolts: 8
- Hole Diameter: 3/4″ (19.05mm)
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 150 is commonly used for:
- Pipe end closure
- Equipment isolation
- Valve and nozzle blanking
- Maintenance shutdown work
- Process and utility piping systems
CAD Drawing Download
This page includes the CAD drawing file for Blind Flange 4″ Class 150, which can be used for drafting, detailing, and piping layout coordination.
Available Blind Flange Class 150 Sizes
This size is part of the Blind Flange Class 150 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 Read the Blind Flange Reference
The nominal size identifies the connected piping size designation, while DN100 is the corresponding metric nominal designation shown in the source data. These labels describe the nominal connection size; they should not be treated as a measured outside diameter or bore.
Class 150 identifies the flange pressure-temperature class designation. It is not, by itself, a complete statement of allowable service conditions. Material, temperature, gasket selection, bolting, fabrication requirements, and the governing project specification must be checked together.
Key dimensional and connection checks
- Flange thickness: Compare the listed thickness with the flange detail used in the drawing or model.
- Stud bolts: The source identifies 5/8" UNC (or M16) x 90 Long. Confirm whether the project uses the inch or metric bolting option before procurement.
- Number of bolts: The connection uses the listed bolt count, which should match the mating flange drilling.
- Hole diameter: The stated hole diameter is a clearance dimension for the bolting arrangement; it is not the same as the stud bolt nominal diameter.
- Weight: Use the published weight for handling, shipping, and preliminary material planning, while recognizing that final handling documentation may depend on the supplied product.
Using the DWG file
The included DWG can support piping layout, equipment connection detailing, and coordination with related flange and fitting drawings. Before using it for fabrication, verify units, insertion scale, mating-face details, gasket seating requirements, and the project material specification.
Related reference opportunities
For broader piping work, link this page to related references for flange dimensions, pipe schedules, flange facing types, gasket selection, stud bolt terminology, and other Class 150 blind flange sizes. These related topics help readers move from a single-component lookup to a complete bolted-joint check.
Frequently Asked Questions
What is a 4 inch Class 150 blind flange used for?
It is used to close the end of a piping system or blank a flanged connection, including equipment, valve, nozzle, maintenance, and future expansion points.
Does a blind flange have a center bore?
No. A blind flange is a solid flange without a center bore. Its purpose is to provide a removable closure at a flanged connection.
What stud bolt size is listed for this flange?
The source lists 5/8" UNC (or M16) x 90 Long. Confirm the required bolting system and project specification before ordering.
How many bolts are listed?
The reference lists 8 bolts. The mating flange must have a compatible drilling pattern.
Is the hole diameter the same as the bolt size?
No. The hole diameter is the flange clearance-hole dimension, while the bolt size identifies the nominal stud or bolt specification. Both must be checked when coordinating the connection.
What standard is referenced for the dimensions?
The source identifies ANSI / ASME B16.5 as the reference standard. Confirm the applicable project requirements and current purchasing specification before fabrication or installation.
Can the DWG be used directly for fabrication?
Use the DWG as a drafting and coordination resource. Confirm drawing units, material, gasket, bolting, facing, and project-specific requirements before releasing fabrication documents.