This reference provides a practical starting point for reviewing a weld neck flange 1 inch Class 600 before drafting, procurement, or fabrication. Use the dimension data below to coordinate the flange with the pipe, gasket, bolts, and adjoining components.
A weld neck flange is not selected by outside dimensions alone. The pipe schedule affects the bore, while the material specification, service conditions, gasket arrangement, and project requirements must be checked separately before the connection is released for construction.
Weld Neck Flange 1″ Class 600
Weld Neck Flange 1″ Class 600 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 1″ Class 600 Dimensions
- Reference Standard: ANSI / ASME B16.5
- Nominal Pipe Size (NPS):1″
- DN Size: DN25
- Outside Diameter:124mm
- Flange Thickness:17.5mm
- Hub Diameter:54mm
- Bore Diameter: varies depending on pipe schedule and pipe wall thickness
- Raised Face Diameter:50.8mm
- Weight: 1.8kg
- Number of Bolts:4
- Stud Bolt Size: 5/8″ UNC (or M16) x 90 Long
- Hole Diameter: 3/4″ (19.05mm)
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″ Class 600 is commonly used for:
- Process piping systems
- Oil and gas lines
- Water and utility piping
- 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″ Class 600, which can be used for drafting, detailing, piping layout coordination, and fabrication reference.
Available Weld Neck Flange Class 600 Sizes
This size is part of the Weld Neck Flange Class 600 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
The listed dimensions describe the flange geometry and connection details used for layout and reference work. For CAD coordination, check the outside diameter, raised face, hub, bolt holes, and bolt pattern against adjacent flanges and available clearance in the piping arrangement.
The bore is identified as schedule-dependent because the flange must align with the internal diameter of the selected pipe. Confirm the pipe schedule and wall thickness before using the flange in a fabrication drawing or bill of materials. This is especially important when matching a weld neck flange to pipe, fittings, valves, and reducers from different reference pages.
Class Designation and Project Checks
The Class 600 designation identifies the flange pressure class, but it should not be treated as a universal allowable pressure for every installation. Final selection requires verification of the flange material, pressure-temperature conditions, gasket, bolting, pipe specification, and governing project requirements.
Drafting and CAD Coordination
The downloadable DWG can support preliminary layout, detailing, and interference checks. Treat the drawing as a dimensional reference and confirm the project’s required units, tolerances, weld details, facing condition, and revision status before using it for fabrication. Related resources such as pipe schedules, flange dimensions, pipe fittings, and piping CAD blocks can help complete the surrounding design reference.
Procurement and Installation Review
- Match the nominal pipe size and schedule to the flange bore.
- Confirm the flange material and applicable pressure-temperature requirements.
- Check gasket type, facing compatibility, and bolting requirements.
- Verify bolt length after accounting for flange, gasket, washer, and nut dimensions.
- Review the latest project documents before fabrication or installation.
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 transition from the flange into the pipe. Its geometry is intended to provide a robust connection and reduce stress concentration compared with simpler flange arrangements.
Why does the bore depend on the pipe schedule?
Pipe schedules use different wall thicknesses within a nominal size. Because the internal opening changes with wall thickness, the flange bore must be checked against the actual pipe selected for the project.
Can the listed bolt size be used for every installation?
The listed bolt information is a reference for this flange configuration. Confirm the required bolt material, length, threading, washers, tightening method, gasket arrangement, and project specification before ordering or installation.
Is the DWG ready for fabrication without review?
No. Use the DWG for drafting and coordination, then verify dimensions, units, tolerances, weld details, materials, and revision requirements against the approved project documents.
What should be checked before selecting this flange?
Check the nominal size, pipe schedule, bore, flange material, facing, gasket, bolting, service conditions, and applicable pressure-temperature requirements. The final connection should be reviewed against the project piping specification.