Lap Joint Flange

• Design: A lap joint flange is a type of flange that consists of two parts: a backing flange and a loose or loose-back flange. The backing flange is welded to the pipe, and the loose flange slides over the backing flange and is bolted to another flange or fitting. The loose flange does not make direct contact with the pipe; instead, it is aligned by the backing flange.


• Applications: Ideal for applications where the alignment of the flanges needs to be adjusted or where ease of disassembly is required. Common in applications where frequent maintenance or adjustments are necessary, such as in piping systems that require regular cleaning or inspection.


• Installation: The backing flange is welded to the pipe. The loose flange is then bolted to the backing flange, providing a flexible connection that can be easily aligned or adjusted.

Chemical and Mechanical Properties Table

Material	Grade	Chemical Composition (wt%)	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)
Carbon Steel	ASTM A105	C: 0.35 max, Mn: 0.60-0.90, P: 0.035 max, S: 0.035 max	205 - 250	420 - 550	20
Stainless Steel	ASTM A182 F304	C: 0.08 max, Cr: 18.0-20.0, Ni: 8.0-10.5	205 - 310	510 - 720	40
Stainless Steel	ASTM A182 F316	C: 0.08 max, Cr: 16.0-18.0, Ni: 10.0-14.0, Mo: 2.0-3.0	205 - 310	510 - 720	40
Alloy Steel	ASTM A234 WP22	C: 0.12-0.20, Cr: 1.0-1.5, Mo: 0.4-0.6	205 - 275	485 - 620	20
High-Temperature Alloy	ASTM A182 F91	C: 0.05-0.15, Cr: 8.0-9.5, Mo: 0.85-1.05	415 - 485	620 - 825	20

Notes:

• Chemical Composition: Indicates the alloying elements in the material, such as chromium and nickel in stainless steels, which contribute to their corrosion resistance.


• Yield Strength: The stress level at which the material starts to deform permanently.


• Tensile Strength: The maximum stress the material can endure while being stretched or pulled before breaking.


• Elongation: Reflects the material's ductility, showing how much it can stretch before failure.