Slip-on flanges vs. Lap joint flanges

Lap joint flanges are extremely similar to slip-on flanges, with the primary difference being that the bore and face have a curved radius to accommodate a lap joint stub-end. Lap joint flanges and stub-end assemblies are commonly employed in circumstances where regular disassembly for inspection is necessary. Sanjay Metal India is a leading Slip-on and Lap Joint Flanges Manufacturer and Supplier in India.

Slip-on flange

A slip-on flange is simply a ring that is fitted over the pipe end, with the flange face extending far enough from the end of the pipe to allow for a weld bead to be applied on the inside diameter. On the rear side of the flange, the OD of the slip-on flange is likewise welded. Slip-on flanges are less expensive to manufacture than weld neck flanges and are easier to align. If Type B or Type C stub ends are utilized, slip-on flanges can also be utilized as lap joint flanges.

The slip-on flange can be fitted to the end of a pipe or to one or more pipe fitting ends. The slip-on flange is installed in such a way that the inserted end of the pipe or fitting is set back or short of the flange face by the thickness of the pipe wall + 1/8 of an inch. This enables for a fillet weld equivalent to the thickness of the pipe wall within the SO flange without causing any damage to the flange face. A fillet weld is also used to join the rear or outside of the flange. A Slip-On flange variant is also available. The Slip-On Reducing Flange is what you’re looking at. This is essentially a bigger (say, 14″) Slip-On flange blank with the Center (pipe) hole cut out (or drilled out) for a 6″ (or other sizes) pipe instead of a 14″ pipe.

Lap joint flange

A lap joint flange is a two-piece device that resembles both a weld-neck flange and a loose slip-on flange. One item is a sleeve called a “Stub-end,” which is fashioned like a small section of pipe with a weld bevel on one end and a narrow shoulder called the hub on the other end. The hub has the same outer diameter as a weld neck flange’s raised face (gasket contact surface). The thickness of the hub is typically between ¼” and 3/8″. A rounded transition (or inner fillet) connects the hub to the sleeve on the back face of the hub. The backing flange is the other component of a Lap Joint Flange. This flange has all of the same common measurements as any other flange (O.D., bolt circle, bolt hole size, etc.), but it does not have a raised face. On one side, the rear, there is a little shoulder with a square cut in the center or pipe hole.

Stainless Steel Lap Joint Flanges Specification, Stainless Steel Lap Joint Flange Size, Stainless Steel Lap Joint Flange Grades, Steel Lap Joint Flange Standards:

• Lap Joint Flange Dimensions:  ANSI Flanges, ASME Flanges, BS Flanges, DIN Flanges, EN Flanges, etc.
• Lap Joint Flange Standards:  ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings
• Lap Joint Flange Class :  150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16, 25, 40 Etc.
• Lap Joint Flange Size:  1/8″ NB TO 48″NB.
• Lap Joint Flange Flange Face Type:  Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)
• Lap Joint Flange DIN:  DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673
• Lap Joint Flange ANSI:  ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48
• Lap Joint Flange BS:  BS4504, BS4504, BS1560, BS10
• Stainless Steel Grades :  ASTM / ASME 201, 202, 301, 304, 304L, 310, 310S, 316L, 316TI, 317, 317L, 321, 347, 409, 409M, 409L, 410, 410S, 420, 430, 431, 441, 444, 446, 17.4PH, 904L

ASTM A182 SS Flanges Grades