This reference provides the listed dimensions, weight, bolt details, and CAD resource for a Weld Neck Flange 1/2 Inch Class 2500. Use the technical list below as a drafting and component-identification aid, then verify the final selection against the project specification.
The most important coordination point is the connection between the flange, pipe bore, gasket, studs, and mating flange. A weld neck flange is not selected by outside diameter alone; the pipe schedule, weld preparation, facing details, material requirements, and service conditions must also agree.
Weld Neck Flange 1/2″ Class 2500
Weld Neck Flange 1/2″ Class 2500 is widely used in piping systems that require strong, leak-resistant flange connections under extremely high-pressure service. It features a long tapered hub that provides excellent stress distribution and is commonly applied in refineries, petrochemical plants, power generation systems, and critical industrial piping where welding strength and connection reliability are essential.
This dimension data is based on ANSI / ASME B16.5-2020.
Weld Neck Flange 1/2″ Class 2500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):1/2″
- DN Size: DN15
- Outside Diameter:133mm
- Flange Thickness:30.2mm
- Hub Diameter:43mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:34.9mm
- Weight: 3.2kg
- Number of Bolts:4
- Stud Bolt Size: 3/4″ UNC (or M20) x 120 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 1/2″ Class 2500 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 1/2″ Class 2500, which can be used for drafting, detailing, piping layout coordination, and fabrication reference.
Available Weld Neck Flange Class 2500 Sizes
This size is part of the Weld Neck Flange Class 2500 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 Weld Neck Flange Reference
The dimension list identifies the flange envelope and connection features, including outside diameter, thickness, hub diameter, raised-face diameter, bolt count, stud information, and hole diameter. These values support layout work, preliminary detailing, and comparison with a mating flange in the same pressure class.
Bore and Pipe Schedule Coordination
The bore is identified as dependent on the pipe schedule and wall thickness. This is a critical distinction for drafting: the flange outside profile may remain unchanged while the bore and weld-end preparation must match the selected pipe. Confirm the pipe schedule and actual fabrication requirements before releasing a drawing.
Bolting and Mating Components
The listed stud bolt size and hole diameter should be checked together with the mating flange, gasket, washers, thread engagement, and available installation clearance. Do not treat the bolt entry as a substitute for a project bolting specification or a final pressure-temperature review.
Using the CAD File
The downloadable DWG can help with piping layouts, equipment-interface coordination, fabrication detailing, and preliminary 2D drafting. Before using it for manufacture, confirm units, insertion scale, facing representation, bore configuration, tolerances, and revision status. For related work, connect this page to the site’s pipe schedule reference, flange terminology guide, raised-face flange references, and DWG download collection.
Design and Installation Check
Use the page data to identify the component, but obtain project approval for material, gasket selection, welding procedure, inspection requirements, pressure-temperature service, and final assembly. The applicable project documents and the latest governing requirements take precedence over a standalone reference drawing.
Frequently Asked Questions
What does the Class 2500 designation identify?
It identifies the flange pressure-class designation used for this reference. Its suitability for a particular service still depends on the applicable pressure-temperature requirements, material, and project specification.
Why can the flange bore vary?
The bore must correspond to the pipe schedule and wall thickness selected for the connection. Check the pipe data and fabrication drawing rather than assuming that every flange in this nominal size has the same bore.
What is the purpose of the tapered hub?
The long tapered hub transitions from the flange body toward the pipe and helps distribute stress at the welded connection. Final weld design and inspection remain subject to the governing project requirements.
Can the DWG be used directly for fabrication?
Use the DWG as a drafting and coordination reference. Verify units, bore, weld-end details, gasket and bolting requirements, tolerances, and revision control before issuing fabrication documents.
What should be checked before installation?
Confirm the mating flange, gasket, studs, bolt-hole alignment, pipe bore, material specification, and service requirements. The page’s notes should be reviewed together with the approved project documents.