This reference page provides dimension and drafting information for a Weld Neck Flange 1 1/2 Inch Class 1500. Use the listed flange dimensions, bolt details, weight, and CAD resource when checking piping layouts, fabrication drawings, or flange selections.
The weld neck design includes a tapered hub that transitions into the pipe connection. Because the bore depends on the pipe schedule and wall thickness, the flange data should be reviewed together with the applicable pipe schedule reference, gasket requirements, material specification, and project design documents.
Weld Neck Flange 1 1/2″ Class 1500
Weld Neck Flange 1 1/2″ Class 1500 is widely used in piping systems that require strong, leak-resistant flange connections under high-pressure service. It features a long tapered hub that provides excellent stress distribution and is commonly applied in process piping, utility lines, refineries, power plants, and industrial systems where welding strength and reliability are essential.
This dimension data is based on ANSI / ASME B16.5-2020.
Weld Neck Flange 1 1/2″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):1 1/2″
- DN Size: DN40
- Outside Diameter:178mm
- Flange Thickness:31.8mm
- Hub Diameter:70mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:73mm
- Weight: 5.9kg
- Number of Bolts:4
- Stud Bolt Size: 1″ UNC (or M27) x 140 Long
- Hole Diameter: 1 1/8″ (28.575mm)
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 1500 is commonly used for:
- Process piping systems
- Oil and gas lines
- Refinery and petrochemical piping
- Extremely high-pressure 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 1500, which can be used for drafting, detailing, piping layout coordination, and fabrication reference.
Available Weld Neck Flange Class 1500 Sizes
This size is part of the Weld Neck 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, pipe schedule, bore size, gasket type, bolt length, and applicable pressure-temperature rating.
How to Use This Weld Neck Flange Reference
The source data identifies the flange by both NPS 1 1/2 and DN40. These designations establish the nominal connection size, while the listed outside diameter, thickness, hub diameter, and raised face diameter describe the flange geometry used for drafting and dimensional checks.
The bore is not treated as a single universal dimension because it varies with the selected pipe schedule and wall thickness. Confirm the mating pipe before using the flange in a fabrication drawing. This is especially important when coordinating the flange with pipe dimensions and schedules or preparing a weld detail.
Bolt and Connection Checks
The bolt count, stud bolt specification, and hole diameter in the source data should be checked against the mating flange and the project bolting requirements. Bolt length can also be affected by flange arrangement, gasket selection, washers, and the amount of thread engagement required by the project.
Weld Neck Flange Drafting Guidance
For CAD work, use the downloadable DWG as a drafting reference, then coordinate its flange face, bolt-hole pattern, hub, and bore with the connected pipe and fittings. The drawing should not replace a project-approved specification or a final fabrication review. Related flange dimension references, piping terminology guides, and CAD/DWG resources can help with broader layout coordination.
Selection and Verification
Before ordering, fabrication, or installation, verify the flange material, pipe schedule, bore, gasket type, stud bolts, and pressure-temperature requirements. The listed standard reference and local project requirements should be reviewed together, particularly where temperature changes, cyclic loading, or high-pressure service are involved.
Frequently Asked Questions
What is a weld neck flange?
A weld neck flange is a flange with a long tapered hub that is welded directly to the pipe. The hub provides a gradual transition between the pipe and flange and helps manage stress at the connection.
What are the nominal size designations for this flange?
The source identifies this flange as NPS 1 1/2 and DN40. These are nominal size designations and should be matched with the selected pipe and mating components.
Why does the bore depend on the pipe schedule?
Pipe schedules can have different wall thicknesses within the same nominal size. Since the internal opening must align with the selected pipe, the bore should be confirmed from the pipe schedule and project details rather than assumed from the nominal flange size alone.
What bolting information is provided?
The source lists the number of bolts, stud bolt size and length, and hole diameter for this flange. Confirm these details against the mating flange, gasket arrangement, material requirements, and approved bolting specification before installation.
Is a CAD drawing available?
Yes. A DWG download is provided for drafting, piping layout coordination, detailing, and fabrication reference. Review the drawing together with the dimension data and project requirements.
Which standard is referenced?
The dimension data identifies ANSI / ASME B16.5 as the reference standard and states that the data is based on ANSI / ASME B16.5-2020. Confirm the project-required standard reference before finalizing procurement or fabrication documents.