This reference provides the dimensional and connection information for a Weld Neck Flange 4 Inch Class 1500. Use the listed values when reviewing flange layouts, preparing piping details, coordinating CAD work, or checking a fabrication package.
The page separates fixed flange details from items that depend on the connected pipe. In particular, the bore must be matched to the pipe schedule and wall thickness rather than assumed from the nominal pipe size alone.
Weld Neck Flange 4″ Class 1500
Weld Neck Flange 4″ 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 4″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):4″
- DN Size: DN100
- Outside Diameter:311mm
- Flange Thickness:53.8mm
- Hub Diameter:162mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:157.2mm
- Weight: 33kg
- Number of Bolts:8
- Stud Bolt Size: 1 1/4″ UNC (or M33) x 195 Long
- Hole Diameter: 1 3/8″ (34.925mm)
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 4″ 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 4″ 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 flange dimensions identify the envelope and connection arrangement of the component. The outside diameter, flange thickness, hub diameter, and raised face diameter are useful for layout and clearance checks. The bolt count, stud bolt size, and hole diameter support bolting and mating-flange coordination.
Nominal Size and Bore Selection
NPS 4 and DN100 identify the nominal pipe size designation. They do not, by themselves, define the bore. The source data correctly notes that the bore varies with pipe schedule and pipe wall thickness. Confirm the connected pipe specification before using the flange in a detailed model, spool drawing, or fabrication sketch.
Weld Neck Geometry
The tapered hub transitions from the flange into the welded pipe connection. This geometry is one reason weld neck flanges are selected for demanding piping arrangements, but the final suitability of a connection depends on the project design conditions, material specification, welding requirements, gasket arrangement, and applicable pressure-temperature evaluation.
Bolting and Mating Components
Check the listed bolt count, stud size, length, and hole diameter against the companion flange, gasket, washers, and installation requirements. Bolt length should be reviewed with the actual flange pair and gasket arrangement; the value on this page should not be treated as a universal requirement for every assembly.
CAD and Drafting Workflow
The downloadable DWG can support preliminary layout, drafting, detailing, and coordination. Before issuing drawings for fabrication, verify the flange face, bore, orientation, material, and project-specific requirements against the approved piping specification and the authoritative dimensional data on this page.
Related Reference Topics
- Weld neck flange dimensions by nominal pipe size
- Class 1500 flange references and companion flange selection
- Pipe schedules and their effect on flange bore
- Flange bolt circles, stud bolts, and gasket coordination
- Piping CAD and DWG details for fittings and flanges
Frequently Asked Questions
What are the listed dimensions for the Weld Neck Flange 4 Inch Class 1500?
The source section lists the outside diameter, flange thickness, hub diameter, raised face diameter, weight, bolt count, stud bolt information, and hole diameter. Review the dimensional list above as the controlling local reference for those values.
Does the 4-inch nominal size define the flange bore?
No. The bore depends on the pipe schedule and wall thickness. Confirm the connected pipe specification before selecting or modeling the bore.
What bolt information is provided?
The reference lists eight bolts, a stud bolt designation of 1 1/4-inch UNC or M33 with the stated length, and the corresponding hole diameter. Confirm compatibility with the mating flange and complete bolting assembly.
What is the purpose of the tapered hub?
The long tapered hub provides the transition from the flange to the welded pipe and helps distribute stresses at the flange-to-pipe connection. Engineering review is still required for the actual service conditions.
Can the DWG be used for fabrication?
The DWG is provided as a drafting, detailing, layout, and fabrication reference. Before fabrication, verify the drawing against the approved project specification, pipe schedule, bore, materials, gasket requirements, and installation details.
Which standard is identified for the dimensional data?
The source identifies ANSI / ASME B16.5 and states that the data is based on ANSI / ASME B16.5-2020. Confirm the governing project requirements and current applicable documents before final design or fabrication.