A slip-on flange is a type of pipe flange that slides over the pipe and is welded on either the inside and outside or both. It is easy to align and cost-effective for low-pressure applications.
Standards, Materials, Sizes and Variations
- Size Range: 15 mm-1800 mm (1/2"-72")
- Standards:
ASME/ANSI B16.5 Class 150-2500
AS2129 Table D, Table E, Table F, Table H, Table J
AS4087 PN 16, PN 21, PN 35
JIS B 2220 5K, 10K, 16K, 20K
EN1092 PN2.5 PN 6, PN 10, PN16, PN25, PN40, PN63, PN100
Plus many others - Materials:
Stainless Steel (Grades 304, 316, Duplex 2205/F51/F53) – for corrosion resistance in marine and chemical applications.
Forged Carbon Steel (ASTM A105, A350/LF2) – for high strength and pressure service.
Plate Steel – cost-effective for general industrial use.
Balcombe Engineering can produce these in a huge range of materials to meet your application. - Variations: Raised Face (RF), Flat Face (FF), Ring Joint and Tonge and grooved
Flat flange or Hubbed depending on the specified stand and customer requirement - Fast Delivery - Stock items same day, custom orders typically 10-20 days
What is a Slipon Flange?
What is a Slip-On Hub Flange?
A slip-on hub flange has a short tapered hub for added strength. It slides over the pipe and is welded on both sides, ideal for medium-pressure systems.
What is a Slip-On Plate Flange?
A slip-on plate flange is flat with no hub. It slips over the pipe and is welded in place, best for low-pressure or non-critical applications.
Applications & Industries
Slip-On Flanges
- Commonly used in low-pressure pipelines for water, air, oil, and gas
- Suitable for cooling, fire-fighting, and process systems
- Widely applied in chemical, shipbuilding, and general engineering
- Ideal where easy alignment and frequent maintenance are required
Slip-On Hub Flanges – Specified by ASME standards
- Designed for moderate-pressure service requiring added hub reinforcement
- Used in petrochemical, refinery, and power generation plants
- Preferred in steam, oil, and gas distribution lines
- Provides stronger weld connection while maintaining easy alignment
Slip-On Plate Flanges -Described in AS2129 and AS4087
- Common in low-pressure, non-critical piping systems
- Widely used in waterworks, HVAC, and food-grade piping
- Suitable for temporary setups, testing, or low-stress connections
- Cost-effective choice for general fabrication and maintenance
Materials & Grades[ONLY PLACEHOLDER]
Our flanges are available in multiple materials:
- Forged Carbon Steel (ASTM A105) for general industrial applications
- Stainless Steel (304L, 316L) for corrosion-resistant requirements
- Duplex Steels (2205,2507,F51,F53) for high-strength, corrosive environments
- Specialized alloys available for extreme service conditions
Material Grade Features Best For
| Material | Grades | Key Features | Applications |
|---|---|---|---|
| Carbon Steel | A105 | High strength, cost-effective | General industrial, oil & gas |
| Stainless Steel | 304L, 316L | Corrosion resistance | Chemical processing, marine |
| Duplex Steels | 2205 2507 |
Superior corrosion resistance | Offshore, high-chloride environments |
Advantages
- Easy to align and install
- Cost-effective for low-pressure systems
- Compact design saves space
- Double-welded for added sealing strength
Limitations
- Not suitable for high pressure or temperature
- Weaker joint than weld neck flanges
- Requires welding on both sides
- Less resistant to fatigue and vibration
Slip-on Flange Welding
Slip-on flanges are slid over the pipe and welded on both the inner and outer edges to ensure a strong, leak-free joint. A small 1.5–3 mm gap is left between the pipe end and flange face for proper weld penetration. Common welding methods include TIG, MIG, and Stick welding. This design is ideal for low to medium-pressure pipelines such as water, air, and oil systems, offering easy alignment and quick installation. For high-pressure or high-temperature service, weld neck flanges are preferred.
Slip-on Flange Applications
Slip-on flanges are widely used in piping systems that require easy alignment, quick installation, and reliable sealing under low to medium pressure conditions.
Common Applications:
- Water, air, oil, and gas pipelines
- Fire-fighting and HVAC systems
- Cooling water and process piping
- General fabrication and plant maintenance
Key Industries We Serve:
- Oil & Gas
- Chemical & Petrochemical
- Marine & Shipbuilding
- Water & Wastewater Treatment
- HVAC & Construction
Frequently Asked Questions
Slip-on flanges are used to connect pipes in low-pressure or
non-critical systems. They are ideal for water, air, gas, and chemical
pipelines, where quick installation and easy alignment are important. Two Slip
on flanges are bolted together with a separating gasket to form a sealed
maintainable joint.
A lap flange works with a stub end, allowing the flange to
rotate for bolt alignment, while a slip-on flange slides directly over the pipe
and is welded in place. Lap flanges suit systems that need frequent disassembly,
while slip-on flanges are for permanent, low-pressure connections. Note the stub
end forms the sealing face.
A loose flange (lap joint flange) is not welded to the pipe —
it slips over a stub end. A slip-on flange is welded on both sides of the pipe.
Loose flanges are easier for alignment and maintenance, whereas slip-on types
give a stronger, semi-permanent joint.
A socket weld flange holds the pipe in a recessed socket and is
welded only on the outside — offering better fatigue resistance for small-bore,
high-pressure systems.
A slip-on flange slides over the pipe and is welded inside and outside
Slide the flange over the pipe, align the bolt holes and flange
faceiwith the gasket face, and weld both inner and outer edges. This ensures
proper sealing and stability.
Yes. Slip-on flanges must be welded both inside and outside to
prevent leaks and ensure joint strength.
The weld neck flange is the strongest, designed for
high-pressure and high-temperature pipelines due to its tapered hub and smooth
stress transition.
No. Slip-on flanges come in both raised face (RF) and flat face
(FF) types. RF is common for process piping, while FF is used with many water
pipe applications.
Yes, as long as the pipe size and pressure class match, a
slip-on flange can be welded to a tee connection.
Use weld neck flanges for high-pressure, high-temperature, or
cyclic applications.
Use slip-on flanges for low-pressure, general-purpose systems where cost and
ease of installation are priorities.
Slip-on flanges are slid over the pipe and then welded on both
the inner and outer edges to secure the connection and prevent leaks.
Two welds (inside and outside) give stronger sealing and better
load distribution, reducing the risk of leakage under pressure.
Why Choose Balcombe Engineering
Quality Assurance
Flanges meeting international standards (ANSI, DIN, JIS, AS)
Extensive Range
Wide selection of flange types, sizes, and materials
Expert Support
Real people, knowledgeable and experienced. Ready to assist with your needs
Competitive Pricing
High-quality flanges at affordable prices
Nationwide Delivery
Prompt service across Australia
Custom Manufacturing
Able to manufacture flanges to your custom drawing specifications
