Lap Joint Flanges

Lap Joint Flanges are similar to other types of industrial flanges, but it does not have a raised face. Lap joint flanges are used in conjunction with a “Lap Joint Stub End”. The total initial cost of a lap joint flange along with a stub end is around one-third higher than that of comparable welding neck flanges. The pressure holding capacity of lap joint flanges is comparatively lower, and the fatigue life for the assembly is only one tenth that of welding neck flanges.

The lap joint flange with the stub end assembly is normally used in piping systems which require regular dismantling for inspection and cleaning. These flanges slip over the pipe, and are not welded or otherwise fastened to it. Bolting pressure is transmitted to the gasket by the pressure of the flange against the back of the pipe lap (Stub End).Lap Joint Flange 2 Lap Joint Flange 1

  • Size: 1/2″ (15 NB) to 48″ (1200 NB)
  • Standards: ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings
  • Pressure Ratings: Class 150, Class 300, Class 400, Class 600, Class 900, Class 1500, Class 2500, PN6, PN10, PN16, PN25, PN40, PN64 etc.
  • Carbon Steel Lap Joint Flanges: ASTM A105/A105N, A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, A694 F42, F46, F48, F50, F52, F56, F60, F65, F70, A516.60, 65, 70 (Spectacle Blind Flange, Spacer Ring/Spade Flange), Steel RST37.2, C22.8
  • Stainless Steel Lap Joint Flanges: ASTM A182 F202, F304/304L/304H, F316/316L, F316H, F316TI, F310, F321, F904L
  • Flange Face Type: Flat Face (FF), Raised Face (RF), Ring Type Joint (RTJ)
  • Coating/Surface Treatment: Anti-rust Paint, Oil Black Paint, Yellow Transparent, Zinc Plated, Cold and Hot Dip Galvanized