ASME B16.5 / B16.47 | EN 1092-1 / DIN / JIS / BS / AS / AWWA | Class 150 – 2500 | ½″ – 80″ | ISO 9001:2015 Certified
Slip on flanges are the most widely used flange type in industrial piping worldwide. A slip on flange has a bore slightly larger than the pipe's outer diameter, allowing it to slide over the pipe end before being secured with two fillet welds — one on the hub (outside) and one on the bore (inside). Standardised under ASME B16.5 for NPS ½″–24″ and ASME B16.47 for NPS 26″–60″ (and up to 80″ on request), they offer a cost-effective, structurally sound connection for general-purpose process piping. Tesco Steel & Engineering, an ISO 9001:2015-certified manufacturer in Mumbai, India, produces slip on flanges in 50+ material grades to nine international standards — supplying EPC contractors, distributors, and OEMs across 50+ countries.
Compared with weld neck flanges, slip on flanges are lighter, easier to align on site (cut length accuracy is less critical), and typically 20–30% less expensive in material and fabrication cost. Their low hub profile makes them ideal for large-bore water, utility, and process piping. Tesco Steel supplies slip on flanges with raised face (SORF), flat face (SOFF), and ring-type joint (SORTJ) facing options, with all surface finishes per ASME B16.5 or equivalent international standards.
Slip on flanges require less machining than weld neck flanges — no long tapered hub to bore and turn. Shorter hub also means less material weight. This results in 20–30% lower per-unit cost, making slip ons the economical choice for large-volume or large-bore piping projects.
The flange slides over the pipe end before welding, so precise pipe cut length is not critical. This simplifies field assembly, reduces re-cutting, and accelerates installation — especially on large bore water treatment, HVAC, and structural piping where accurate cuts are difficult.
Available from NPS ½″ to 80″, slip on flanges cover every bore size from instrument-scale to large-diameter water mains. Tesco Steel produces slip ons to ASME B16.5, B16.47, EN 1092-1, DIN, JIS, BS, AS, AWWA, SABS, and NFE standards — the broadest multi-standard availability in our range.
Two fillet welds (hub and bore) give the joint comparable strength and leak resistance to a butt-welded connection. The bore weld seals the annular gap between pipe OD and flange bore, preventing fluid ingress and crevice corrosion at the interface.
Raised face (SORF) for standard spiral-wound gaskets and most process applications; flat face (SOFF) for pairing with cast iron, ductile iron, or GRP flanges where a raised face would impose bending stress. Both available in all pressure classes and materials.
Tesco Steel maintains ready stock of SORF and SOFF flanges in NPS ½″–24″, Class 150–600, SS 304/316 and A105. Custom sizes, higher classes, and exotic alloys are manufactured on order. Mill Test Certificates per EN 10204 3.1/3.2 ship with every order.
| Slip On Flanges — Full Specification Range | |
|---|---|
| Size Range | NPS ½″ to 80″ (DN 15 to DN 2000); ASME B16.5 up to NPS 24″; ASME B16.47 up to NPS 60″+ |
| Pressure Class | Class 150, 300, 400, 600, 900, 1500, 2500 (ASME B16.5); Class B, D, E, F (AWWA C207) |
| PN Rating | PN 2.5, PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100, PN 160, PN 250, PN 320, PN 400 |
| Facing Types | Raised Face (RF / SORF), Flat Face (FF / SOFF), Ring-Type Joint (RTJ / SORTJ) |
| Governing Standards | ASME B16.5, ASME B16.47, EN 1092-1, DIN, JIS, BS 4504, BS 10, AS 2129, AS 4087, AWWA C207, SABS 1123, NFE 29203 |
| Carbon Steel | ASTM A105 |
| LTCS Slip On Flanges | ASTM A350 LF2 |
| Stainless Steel Slip On Flanges | ASTM A182 F304 / F304H / F304L / F316 / F316H / F316L / F316Ti / F309 / F310 / F317 / F317L / F321 / F347 / F904L |
| Alloy Steel Slip On Flanges | ASTM A182 F5 / F9 / F11 / F12 / F21 / F22 / F91 |
| Duplex & Super Duplex Slip On Flanges | ASTM A182 F51 (UNS S31803), F53 (S32750), F55 (S32760), F60 (S32205) |
| Nickel Alloy Slip On Flanges | UNS N02200, UNS N02201 |
| Monel Slip On Flanges | UNS N04400 (Monel 400), UNS N05500 (Monel K500), Alloy 20 |
| Inconel / Incoloy Slip On Flanges | UNS N06600, N06601, N06625, N08800, N08810, N08825 |
| Hastelloy Slip On Flanges | UNS N10276 (C276), N06022 (C22), N10665 (B2), N06455 (C4) |
| Copper Nickel Slip On Flanges | C70600 (90/10 CuNi), C71500 (70/30 CuNi), C71640 |
| Titanium Slip On Flanges | Grade 1, Grade 2, Grade 3, DTH 3.7035, DTH 3.7055 |
| Surface Coatings / Treatments | Hot-Dip Galvanizing (GI), Sand Blasting, Shot Peening, Epoxy Coating, FBE Coating |
| Certifications | ISO 9001:2015, PED 2014/68/EU, NACE MR0175, EN 10204 3.1 / 3.2 Mill TC, IBR |
| Factor | Slip On | Weld Neck | Socket Weld | Blind |
|---|---|---|---|---|
| NPS Range | ½″ – 80″ | ½″ – 60″+ | ½″ – 4″ | ½″ – 60″+ |
| Welds Required | 2 fillet welds | 1 butt weld | 1 fillet weld | No weld (blind) |
| Pipe Cut Accuracy | ✓ Forgiving | ✗ Precise | ✗ Precise | N/A |
| Radiographic Inspection | ✗ Limited | ✓ Full RT | ✗ Not possible | N/A |
| Cost vs Weld Neck | ✓ ~20–30% lower | Baseline | ✓ Lower | Higher |
| Cyclic / Fatigue Service | Acceptable | ✓ Best | Acceptable | ✓ Good |
| Large Bore (>24″) | ✓ Yes (B16.47) | ✓ Yes (B16.47) | ✗ No | ✓ Yes |
| Line Closure / Isolation | ✗ No | ✗ No | ✗ No | ✓ Yes |
| Industry | Typical Slip On Flange Application |
|---|---|
| Oil & Gas | Crude oil transfer headers, tank farm piping, utility water lines on onshore facilities |
| Petrochemical | Process plant utility headers, cooling water systems, non-critical process lines in A105 or SS 316L |
| Water & Wastewater | Large-bore water mains (AWWA C207), sewage piping, desalination plant headers in duplex or CuNi |
| Power Generation | Cooling water, condensate, and auxiliary steam systems; ash slurry in epoxy-coated A105 |
| Construction & HVAC | Building services chilled water, fire protection, compressed air; galvanized slip ons for structural pipe supports |
| Shipbuilding & Marine | Ballast water systems, fuel oil lines, seawater cooling in Copper Nickel 90/10 per BS 4504 |
| Food & Pharmaceutical | Clean utilities (CIP/SIP) in SS 316L; hygienic flat face flanges mating with PTFE-lined pipe |
| JIS 2K Slip On Flange |
| JIS 5K Slip On Flange |
| JIS 10K Slip On Flange |
| JIS 16K Slip On Flange |
| JIS 20K Slip On Flange |
| JIS 30K Slip On Flange |
| ANSI B16.1 Class 125 Slip On Flange |
| ANSI B16.1 Class 250 Slip On Flange |
| SABS 1123 Class 600 Slip On Flange |
| SABS 1123 Class 1000 Slip On Flange |
| SABS 1123 Class 1600 Slip On Flange |
| SABS 1123 Class 2500 Slip On Flange |
| SABS 1123 Class 4000 Slip On Flange |
Tesco Steel & Engineering exports slip on flanges to: UAE, Saudi Arabia, Kuwait, Qatar, Oman, Bahrain, Iraq (GCC & Middle East); USA, Canada, Mexico, Venezuela, Colombia, Peru (Americas); Germany, Italy, Netherlands, UK, Turkey, Russia, Kazakhstan (Europe & CIS); Nigeria, South Africa, Kenya, Tanzania, Zambia, Angola, Congo, Sudan (Africa); India, Malaysia, Thailand, Indonesia, Philippines, Vietnam, Singapore, China, Japan (Asia-Pacific); and Australia, Israel, Jordan, Afghanistan, Pakistan, Yemen. Domestic supply covers all major industrial hubs across India.
Specify NPS, pressure class, standard, material, facing, and quantity — we respond within 24 hours with price and lead time.
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