This reference provides the dimensional data, bolt information, weight, and CAD resource for a Weld Neck Flange 5 Inch Class 150. Use the listed values when checking piping layouts, preparing fabrication details, or coordinating a flange connection with the selected pipe and gasket arrangement.
A weld neck flange is identified by its tapered hub and butt-weld connection. The hub transitions into the flange body, making the component distinct from slip-on, threaded, socket-weld, and blind flange designs. The source data on this page should remain the controlling reference for the dimensions shown.
Weld Neck Flange 5″ Class 150
Weld Neck Flange 5″ 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 5″ Class 150 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):5″
- DN Size: DN125
- Outside Diameter:254mm
- Flange Thickness:22.4mm
- Hub Diameter:164mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:185.7mm
- Weight: 9.1kg
- Number of Bolts:8
- Stud Bolt Size: 3/4″ UNC (or M20) x 95 Long
- Hole Diameter: 7/8″ (22.225mm)
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 5″ 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 5″ 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 Read the Weld Neck Flange Dimensions
The dimensional list separates the flange geometry from the connection details. Outside diameter and flange thickness describe the main flange envelope, while hub diameter and raised face diameter help with detailing, mating-face coordination, and clearance checks.
The bore diameter is not a single universal value for every installation. It must be coordinated with the pipe schedule and actual pipe wall thickness. This is especially important for a weld neck flange because the bore and tapered hub must align with the pipe preparation and the intended butt-weld connection.
Bolting and Mating Components
The bolt count, stud bolt specification, and hole diameter should be reviewed together rather than treated as separate drafting labels. Confirm that the mating flange uses the same nominal size, pressure class, facing arrangement, and compatible bolting details. Gasket selection, washer practice, tightening procedure, and material compatibility should also be checked against the project specification.
Using the CAD File
The downloadable DWG can support piping layout, equipment-interface coordination, fabrication detailing, and drawing development. Treat the CAD file as a dimensional reference, then verify the selected pipe schedule, bore, flange material, facing, and project requirements before issuing fabrication or installation documents.
Related Reference Topics
- Compare this flange with other pipe flange types when selecting a connection for a piping system.
- Review flange dimensions and pressure classes before coordinating mating components.
- Use a pipe schedule reference to confirm the bore and wall-thickness relationship.
- Consult piping drafting and CAD references when incorporating the DWG into a project drawing.
Frequently Asked Questions
What does a weld neck flange do?
A weld neck flange connects to the pipe through a butt weld and uses a tapered hub to provide a gradual transition between the pipe and flange body. Its geometry is intended to support a robust connection where welding quality and stress management are important.
Is the bore fixed for every Weld Neck Flange 5 Inch Class 150?
No. The bore must be matched to the pipe schedule and pipe wall thickness. Confirm the bore against the actual pipe and the fabrication drawing before ordering or welding.
What should be checked before selecting the bolts?
Check the mating flange, bolt-hole arrangement, stud specification, required length, gasket, flange material, and project installation requirements as one complete connection. Do not rely on nominal size alone.
Can the DWG be used directly for fabrication?
The DWG is useful for drafting and coordination, but fabrication should proceed only after the drawing has been checked against the applicable project specification, pipe schedule, material requirements, facing details, and current approved design information.
Where does this flange fit within a Class 150 size series?
This flange is one size in the Weld Neck Flange Class 150 series. Related size pages can be used to compare available dimensional data and CAD resources, while each selected size should be verified independently.