This reference page provides the dimension and installation information for a Weld Neck Flange 1 1/2 Inch Class 150. Use the listed data when reviewing piping layouts, preparing fabrication details, or coordinating the accompanying DWG file. Because the bore depends on the connected pipe schedule and wall thickness, the flange should be matched to the actual pipe specification before detailing or fabrication.
Weld Neck Flange 1 1/2″ Class 150
Weld Neck Flange 1 1/2″ Class 150 is widely used in piping systems that require strong, leak-resistant flange connections. It features a long tapered hub that provides excellent stress distribution and is commonly applied in process piping, utility lines, and industrial systems where welding strength and reliability are important.
This dimension data is based on ANSI / ASME B16.5-2020.
Weld Neck Flange 1 1/2″ Class 150 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):1 1/2″
- DN Size: DN40
- Outside Diameter:127mm
- Flange Thickness:15.9mm
- Hub Diameter:65mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:73mm
- Weight: 1.8kg
- Number of Bolts:4
- Stud Bolt Size: 1/2″ UNC (or M14) x 70 Long
- Hole Diameter: 5/8″ (15.875mm)
What Is a Weld Neck Flange?
A weld neck flange is a type of pipe flange designed with a long tapered hub that is welded directly to the pipe. This design helps reduce stress concentration at the flange base and provides better strength under pressure, temperature fluctuation, and cyclic loading.
Common Applications
Weld Neck Flange 1 1/2″ Class 150 is commonly used for:
- Process piping systems
- Oil and gas lines
- Water and utility piping
- High-temperature service
- Pressure piping connections
- Industrial fabrication and maintenance work
CAD Drawing Download
This page includes the CAD drawing file for Weld Neck Flange 1 1/2″ Class 150, which can be used for drafting, detailing, piping layout coordination, and fabrication reference.
Available Weld Neck Flange Class 150 Sizes
This size is part of the Weld Neck 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, pipe schedule, bore size, gasket type, bolt length, and applicable pressure-temperature rating.
How to Use This Weld Neck Flange Reference
The dimensional list identifies the flange envelope, hub, face, bolt arrangement, stud information, and weight. These values support preliminary layout and drafting, while the connected pipe specification determines the bore selection. For a complete connection review, compare this page with the applicable pipe schedule, gasket type, stud bolt specification, and flange material.
Why the Weld Neck Design Matters
The tapered hub creates a gradual transition between the flange and pipe. In service, that geometry is intended to provide a more controlled load path than simpler flange profiles. The quality of the butt-weld, pipe alignment, material compatibility, and inspection requirements remain essential to the performance of the completed connection.
Drafting and CAD Coordination
The downloadable DWG is useful for placing the flange in piping arrangements, checking bolt-hole orientation, and developing fabrication or installation drawings. Treat the CAD file as a drafting reference and verify the drawing against the project specification and the dimensional data on this page before issuing it for manufacture.
Related Reference Topics
- Compare this page with the site’s pipe schedule and pipe dimension references when selecting the flange bore.
- Review related flange types and facing references when checking gasket and mating-connection details.
- Use the Class 150 weld neck flange size index to locate other nominal sizes and their CAD resources.
- Consult the piping terminology reference for explanations of NPS, DN, hub, raised face, and bolt-circle terms.
Verification Before Release
Before procurement, fabrication, or installation, confirm that the listed flange matches the project’s pipe schedule, material, facing, gasket, bolt assembly, and pressure-temperature requirements. The project engineer or responsible piping specialist should approve the final connection for its intended service.
Frequently Asked Questions
What does a weld neck flange do?
A weld neck flange connects to the pipe through a welded tapered hub. Its geometry helps manage the transition between the pipe and flange and is commonly selected where connection strength and resistance to service loading are important.
Does the flange bore stay the same for every pipe schedule?
No. The bore must be selected to match the connected pipe’s schedule and wall thickness. Confirm the pipe specification before using the flange in a fabrication drawing or purchase request.
What bolt information is provided on this page?
The reference data identifies the bolt count, stud bolt size, and hole diameter for this flange. Confirm bolt material, thread requirements, length, washers, and tightening practice against the project specification.
Can the DWG file be used directly for fabrication?
The DWG is intended as a drafting, layout, and fabrication reference. Review it against the page data, project drawings, material requirements, and the applicable purchasing or engineering specification before release.
Is Class 150 by itself enough to select a flange?
No. Selection also requires review of the service, material, facing, connected pipe, gasket, bolting, and applicable pressure-temperature requirements. Final suitability should be verified by the responsible engineer or piping specialist.