Slip-on flanges are one of the most widely used and easiest to install flange types in piping systems. They can be directly slipped onto pipe ends and fillet welded, requiring no precise alignment and offering high construction efficiency. The nickel alloy slip-on flanges supplied by Hefei Tailan Metal Co., Ltd. are manufactured from high-quality nickel-based alloy forgings or plates through multiple precision processes including forging/cutting, solution heat treatment, machining, drilling, and pickling/polishing. Featuring convenient installation, economical cost, reliable sealing, and excellent corrosion resistance, they are specifically designed for pipe connections in medium pressure, corrosive service conditions.
Difference from Welding Neck Flanges:
Slip-On Flange: Slips onto pipe end, fillet welded inside and outside, suitable for medium pressure
Welding Neck Flange: Butt welded to pipe, tapered hub transition, suitable for high pressure, demanding conditions
Supply Range
Nominal Diameter (DN/NPS): DN15 – DN600 (1/2 inch – 24 inches); Larger diameters negotiable
Pressure Class: Class 150, 300, 600, 900, 1500 (ASME)
Facing Type: Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ)
Flange Type: Slip-On Flange, Plate Flange
Bore Diameter (B): 1-3mm larger than pipe OD for easy slipping
Hub Diameter (X): Related to flange OD and pressure class
Machining Precision: Sealing surface roughness Ra 3.2μm – 6.3μm (as per standard requirements)
Surface Condition: Machined, Pickled, Polished optional
Marking Method: Steel stamp marking on flange outer edge, conforming to MSS SP-25 or customer requirements
Strict Non-Destructive Testing
Penetrant Testing (PT) : Detecting surface-opening defects, conforming to ASTM E165 standard
Hardness Testing: Verifying heat treatment effectiveness and mechanical property uniformity
Multiple Facing Types Available
Various facing types available according to service conditions:
Raised Face (RF) : Most common, suitable for Class 150-1500
Ring Type Joint (RTJ) : For high pressure, strict leakage prevention
Flat Face (FF) : For cast iron flanges or low pressure conditions
Stock Availability, Emergency Response
We maintain inventory of slip-on flange blanks for mainstream grades such as Inconel 600/625, Monel 400, and Hastelloy C-276. Orders can be quickly arranged for machining.
Dimensions, Standards and Size Range
When a buyer specifies Slip-on flanges, the first question is almost always which
dimensional standard applies, because it fixes the bolt circle, the flange
diameter and the allowable centre-to-end geometry. For nickel alloy flanges
that split is as follows.
| Size band | Dimensional standard | Typical usage |
|---|---|---|
| NPS 1/2 – NPS 24 (DN15 – DN600) | ASME B16.5 | Process piping, the overwhelming majority of industrial orders |
| NPS 26 – NPS 48 (DN650 – DN1200) | ASME B16.47 Series A and B | Large-bore lines, tank nozzles and offshore risers |
Note that ASME B16.5 and B16.47 are dimensional standards only. They
govern geometry, tolerances and marking; they say nothing about metallurgy. The
material requirement is written separately, and for nickel alloys the usual
reference is ASME SB-462, which covers forged or rolled nickel alloy pipe
flanges, forged fittings and valves intended for corrosive high-temperature
service. SB-462 explicitly lists UNS N10276 (Hastelloy C-276), UNS N06022
(Hastelloy C-22), UNS N06200, UNS N08020 (Alloy 20) and UNS N08031 among the
grades it covers. Where the item is supplied as a forging rather than a rolled
ring, ASME SB-564 (Nickel Alloy Forgings) is the governing material
specification, and it covers UNS N06625 (Alloy 625), UNS N04400 (Monel 400),
UNS N06600 (Inconel 600) and UNS N10276 among others.
Pressure Class and Facing
Nickel alloy flanges are ordered against ASME B16.5 pressure classes
(Class 150 through Class 2500) or against the EN 1092-1 PN ratings. The facing
has to be matched to the service, and this is where most late-stage
non-conformances occur:
- Raised Face (RF) — the default for Class 150–2500
and the correct choice for general process service. - Ring Type Joint (RTJ) — required for high-pressure or
high-temperature service where a leak-tight metal-to-metal seal is
mandatory. - Flat Face (FF) — used where the mating flange is
cast iron or where the bolting is at very low pressure.
Slip-on flanges supplied by Hefei Tailan Metal is machined from forged or rolled
nickel alloy stock with the hub a hub that slides over the pipe and is fillet welded. If your project requires an
unusual facing, a specific corrosion allowance, or a matching pipe wall
thickness, state it on the enquiry and we will confirm the exact line item
against the applicable standard before quotation.
Matching Pipe and Fitting Supply
Flanges are only one half of a pressure boundary, and dimensional
compatibility with the pipe and fittings they connect to is what determines
whether the joint assembles correctly on site. We supply the matching
nickel alloy pipe and tube in the same grade family, so a single order can cover
pipe, fittings and flanges on one heat-number basis. For socket-weld and
threaded pressure classes the fitting dimensions follow ASME B16.11 rather than
B16.9, while butt-weld fittings follow B16.9 and pipe wall thicknesses follow
ANSI B36.10M for carbon steel and B36.19M for stainless. If you are matching an
existing line, send us the nominal size, schedule or wall thickness, class and
facing, and we will confirm dimensional compatibility in writing before the
order is placed.
Need the pipe first? Our weld neck flange and
nickel alloy plate flange pages carry the same grade cross-reference tables, and
the flange types we stock overview lists every flange type we manufacture.
Enquiries are answered with a quotation, not a catalogue reply.
