Joining, flanges and sealing
Slip-on flange
Creating a detachable joint between piping, valves and equipment
Specialist selection guide
What should be reviewed before selecting this product?
A slip-on flange slides over the pipe and is commonly attached with internal and external fillet welds. It is easy to align and install, but fatigue limits and weld details require review for cyclic or critical service.
Technical selection path
- 1
Match class, facing and grade to the piping class
- 2
Check bore and pipe clearance
- 3
Specify internal and external weld details
- 4
Review thermal cycling, vibration and fatigue
- 5
Control pipe-end setback from the flange face
Key strengths
- Easy alignment and installation
- Lower initial cost in many sizes
- No flange butt-weld bevel required
Selection limitations
- Generally lower fatigue strength than weld neck
- Two fillet welds and a potential crevice region
- Restricted in some critical services
Typical applications
Where can this option be considered?
- Utility and general services
- Low-cycle lines within suitable ratings
- Projects prioritising simple installation
Reference standards
A standard does not replace the project specification
Common technical questions
Concise answers before enquiry
What is the main difference between slip-on and weld-neck flanges?
A slip-on uses fillet welds around the pipe, while a weld neck uses a butt weld and tapered hub for improved stress transfer.
Is a slip-on flange suitable for every service?
No. The project code may restrict it for severe cyclic, high-temperature, lethal or other special service.
Locations requiring assembly, inspection or periodic maintenance
Standard, class, material group, facing, gasket and bolting
Initial review sheet
Technical attributes to review
Final values must come from project specifications, calculations and manufacturer data. This table defines the information scope.
FamilyIndustrial flanges
Main groupJoining, flanges and sealing
Materials to evaluateCarbon steel, Stainless steel, Alloy steel, Low-temperature steel
Connections to evaluateWelded, Threaded, Socket, Loose/lap
Typical mediaAll piping services
Relevant industriesOil and gas, Refining, Petrochemical, Power generation, Water and utilities
Reference standardsASME B16.5 · ASME B16.47 · ASME B16.36 · API 6A · EN 1092-1 · BS 10
Enquiry checklist
Include this information with your request
Standard and class
Nominal size
Facing
Material and grade
Pipe schedule
Drilling and dimensions
Before substitution
A matching name does not guarantee interchangeability
Installation dimensions, pressure rating, wetted materials, sealing design, construction standard, testing and documentation must be checked independently.
Adjacent types
Other options in this family
Final technical approval is required
This page is educational and intended for initial screening. Final selection must be approved against project requirements, actual service conditions and manufacturer documentation.
Send request for review