This reference provides the dimensional data, bolt information, weight, and CAD resource for a Weld Neck Flange 18 Inch Class 1500. Use the listed values for drafting and preliminary coordination, while confirming the final selection against the project specification and the applicable piping requirements.
The flange bore requires particular attention because it is associated with the pipe schedule and wall thickness. For related dimensional work, compare this page with the site references for pipe schedules, flange dimensions, stud bolt sizes, and pipe fittings.
Weld Neck Flange 18″ Class 1500
Weld Neck Flange 18″ 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 18″ Class 1500 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):18″
- DN Size: DN450
- Outside Diameter:914mm
- Flange Thickness:162.1mm
- Hub Diameter:597mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:533.4mm
- Weight: 795kg
- Number of Bolts:16
- Stud Bolt Size: 2 3/4″ UNC (or M72) x 495 Long
- Hole Diameter: 2 7/8″ (73.025mm)
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 18″ 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 18″ 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 Flange Reference
A weld neck flange is welded directly to the pipe through its tapered hub. When reviewing the dimensional list, separate the features used for layout from those used for connection checks. The outside diameter, flange thickness, hub diameter, and raised face diameter support modeling and detailing. The bore must be matched to the actual pipe specification rather than selected from the flange size alone.
Checking the bolting arrangement
The number of bolt holes, hole diameter, stud bolt size, and bolt length should be reviewed together. These details affect flange fit-up, gasket alignment, tool access, and the available thread engagement. Metric and inch designations should not be treated as interchangeable without confirmation from the project specification, supplier documentation, and the selected bolting material.
Using the CAD file
The downloadable DWG can support piping layout, equipment-interface coordination, fabrication detailing, and preliminary model development. Before issuing a drawing, check the flange face, bore, bolt-hole pattern, orientation, units, and any project-specific machining or facing requirements. The CAD file should be treated as a drafting reference and not as a substitute for the approved fabrication drawing.
Design and installation checks
Flange dimensions alone do not establish whether a connection is acceptable for service. Confirm the material specification, gasket type, pipe wall, pressure-temperature requirements, bolt material, tightening procedure, and applicable inspection requirements. These checks are especially important where thermal cycling, vibration, cyclic loading, or corrosive service may affect joint performance.
For broader coordination, useful related references include raised face flange terminology, pipe schedule selection, flange gasket types, and piping isometric drafting.
Frequently Asked Questions
What does the bore depend on for this weld neck flange?
The bore varies with the pipe schedule and pipe wall thickness. Confirm the bore against the actual pipe specification before fabrication or installation.
What information should be checked with the bolt size?
Review the stud bolt designation together with the bolt-hole diameter, bolt count, flange thickness, gasket arrangement, and required thread engagement. The project specification should govern the final bolting selection.
Can the DWG file be used for fabrication?
The DWG is useful for drafting, layout coordination, and fabrication reference. Fabrication should proceed only after the drawing, material, bore, facing, bolting, and inspection requirements have been approved.
Does Class 1500 alone determine the allowable operating pressure?
No. The applicable pressure-temperature rating depends on factors such as material and service temperature. Confirm the rating using the applicable standard, material specification, and project design basis.
What should be confirmed before installation?
Confirm the flange dimensions, pipe alignment, bore, gasket, facing condition, bolt compatibility, tightening method, and project-specific pressure and inspection requirements.