Product Overview
The Lap Joint (LJ) Flange is a specialized “loose” flange used in conjunction with a lap joint stub end. Unlike a Slip-On flange, which is welded directly to the pipe, the Lap Joint flange is not welded to the pipe at all. Instead, it sits behind the stub end, which is the component welded to the pipe. This design provides unique advantages for systems where alignment is difficult or where the pipe material is expensive.
Simplified Alignment and Maintenance
Because the flange is free to rotate on the pipe until it is bolted to the mating flange, alignment of bolt holes is effortless. This is a major benefit in tight spaces or when working with large-diameter Schedule 40 pipes. Additionally, since the flange never comes into contact with the process fluid, it is less susceptible to internal corrosion, extending its service life compared to welded-in-place options.
Cost-Effective Industrial Solution
In systems using expensive alloys like SS 316L, lap joint flanges can offer significant cost savings. Only the stub end needs to be the expensive material grade, while the backing lap joint flange can sometimes be a lower-cost grade (though we provide full SS 304/316L for total corrosion resistance). This modular setup is ideal for Schedule 10 light-wall systems that require frequent dismantling for cleaning or inspection.
Industry-Standard Compliance
All our lap joint flanges are manufactured to ASME B16.5 and ASTM A182 standards. They feature a smooth bore and a flat face design, ensuring they can easily accommodate the radius of a standard stub end. This ensures a high-integrity, leak-proof joint when properly torqued with industrial gaskets.




