This reference provides the dimensional data, bolt information, weight, and CAD resource for a Weld Neck Flange 3 Inch Class 1500. Use the listed values when reviewing flange layouts, piping details, and fabrication drawings, while treating the project specification and applicable standard as the final authority.
The bore is identified separately because it depends on the mating pipe schedule and wall thickness. For accurate flange selection, compare this page with the relevant pipe schedule reference, gasket details, bolt requirements, and material specification.
Weld Neck Flange 3″ Class 1500
Weld Neck Flange 3″ 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 3″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):3″
- DN Size: DN80
- Outside Diameter:267mm
- Flange Thickness:47.8mm
- Hub Diameter:133mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:127mm
- Weight: 21.8kg
- Number of Bolts:8
- Stud Bolt Size: 1 1/8″ UNC (or M30) x 180 Long
- Hole Diameter: 1 1/4″ (31.75mm)
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 3″ 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 3″ 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 Read This Flange Reference
A weld neck flange is welded directly to the pipe through its tapered hub. In a piping assembly, the outside diameter, thickness, bolt-hole arrangement, raised face, and hub geometry affect fit-up and connection detailing. The flange dimensions should therefore be reviewed together rather than treated as isolated measurements.
The listed bore diameter is not a single universal value for every pipe connection. It must be coordinated with the pipe’s schedule and wall thickness so the flange bore, weld preparation, and pipe internal passage are compatible. This is an important cross-check when using the page for pipe spool drawings, isometric details, or fabrication takeoffs.
Bolt and Gasket Coordination
Use the stated stud bolt size, length, hole diameter, and bolt count when preparing a connection detail. Bolt selection should still be checked against the flange material, gasket type, facing condition, assembly method, and project requirements. The raised face also needs to match the selected gasket and the mating flange arrangement.
Using the CAD Download
The downloadable DWG can support drafting, layout coordination, and preliminary detailing. Before issuing a fabrication or installation drawing, verify the drawing against the dimensional list, the mating pipe, the selected bore, and the governing project documents. A CAD file should not replace engineering review or the applicable flange and piping requirements.
Related Reference Topics
- Pipe schedules: use schedule information to coordinate the flange bore with the pipe wall.
- Flange types: compare weld neck, slip-on, blind, and socket weld configurations when developing a piping connection.
- Flange terminology: review raised face, hub, bore, bolt circle, and stud bolt terms before checking a drawing.
- CAD and DWG resources: use related flange and fitting drawings to maintain consistent drafting details across a piping system.
Frequently Asked Questions
What is the bore of this weld neck flange?
The bore varies with the connected pipe schedule and wall thickness. Confirm the required bore before fabrication or installation.
What bolt information is provided?
The reference lists the number of bolts, stud bolt size and length, and hole diameter. These details should be checked with the gasket, flange material, and project assembly requirements.
Can the DWG be used for fabrication?
The DWG is provided as a drafting and coordination reference. Verify its dimensions and connection details against the listed data, project documents, and engineering requirements before releasing fabrication information.
Why is a weld neck flange used?
Its tapered hub provides a gradual transition from the flange to the pipe and is intended to support a welded connection where strength and stress control are important considerations.
What should be checked before installation?
Confirm the flange material, pipe schedule, bore, gasket, bolt requirements, facing arrangement, and applicable pressure-temperature requirements before installation.