This reference provides the dimensional and connection details for a Weld Neck Flange 16 Inch Class 1500, including outside diameter, thickness, hub dimensions, weight, bolt information, and hole diameter. Use the listed values as a drafting and coordination reference, then verify them against the project specification before fabrication or installation.
The weld neck configuration is especially important where the flange-to-pipe transition, welding detail, and alignment must be coordinated carefully. The flange dimensions should be reviewed together with the pipe schedule, bore requirement, gasket selection, and mating flange information.
Weld Neck Flange 16″ Class 1500
Weld Neck Flange 16″ 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 16″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):16″
- DN Size: DN400
- Outside Diameter:826mm
- Flange Thickness:146mm
- Hub Diameter:552mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:469.9mm
- Weight: 591kg
- Number of Bolts:16
- Stud Bolt Size: 2 1/2″ UNC (or M64) x 445 Long
- Hole Diameter: 2 5/8″ (66.675mm)
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 16″ 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 16″ 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 dimensional list identifies the main geometry needed for piping layout, CAD detailing, flange coordination, and fabrication review. The outside diameter and flange thickness describe the flange envelope, while the hub diameter and tapered hub define the transition toward the pipe. These dimensions are useful when checking clearances, bolt access, and connections to adjacent components.
The bore diameter is not a single universal value in this reference because it depends on the pipe schedule and wall thickness. Confirm the connected pipe designation before preparing a fabrication drawing. A nominal pipe size identifies the intended pipe connection, but it does not by itself define every internal dimension of the finished assembly.
Bolting and Face Coordination
Review the stated number of bolts, stud bolt designation, bolt length, and hole diameter as a coordinated set. Bolt selection should also account for the mating flange, gasket arrangement, washer and nut requirements, available thread engagement, and project material specifications. Do not treat the flange weight as an installation lifting limit or as a substitute for a handling review.
Drafting and CAD Workflow
The downloadable DWG can support preliminary drafting, piping layout coordination, equipment-interface review, and fabrication reference. Before issuing a drawing, compare the CAD geometry with the dimensional list and confirm the selected bore, facing arrangement, gasket details, and connection orientation. A drawing should clearly distinguish nominal pipe information from flange geometry.
For related design work, connect this reference with the site’s resources on pipe schedules, flange types, gasket selection, stud bolts, and piping CAD blocks. Those references help readers interpret how this weld neck flange fits into a complete piping connection rather than reviewing the flange in isolation.
Frequently Asked Questions
What is a weld neck flange?
A weld neck flange has a long tapered hub and is welded directly to the pipe. Its geometry provides a gradual transition from the flange into the pipe and is commonly reviewed where welding, cyclic service, and connection integrity are important.
Why does the bore depend on the pipe schedule?
Pipe schedules represent different wall-thickness selections for a nominal pipe size. Because the internal opening changes with wall thickness, the flange bore must be checked against the actual pipe schedule selected for the project.
What does the Class 1500 designation identify?
The Class 1500 designation identifies the flange class used for specification and rating coordination. The applicable pressure-temperature rating still depends on the material, service conditions, and governing project requirements.
Can the listed stud bolt size be used without further checking?
Use the listed stud bolt information as a reference, but confirm compatibility with the mating flange, gasket, nuts, washers, material specification, and required assembly engagement before ordering or installation.
What should be checked before using the DWG?
Compare the drawing with the listed dimensions and confirm the pipe schedule, bore, facing details, bolt-hole requirements, orientation, and project-specific tolerances. The CAD file should support engineering review, not replace it.