S/STEEL LAP JOINT FLANGES

S/STEEL LAP JOINT FLANGES

S/STEEL LAP JOINT FLANGES

Lap Joint flanges, often called Back Up, Loose Ring or Van Stone Flanges, must be used with a Stub End fitted with a flange. These ring flanges are commonly produced and stocked in several different materials. The combination of the two makes its cost higher than an equivalent welded flange. The pressure resistance of such an assembly is equivalent to that of a “slip on” flange, and its resistance to fatigue is much lower than that of a welded flange flange. Their use for severely constrained services should be avoided. It is mainly used for services requiring frequent disassembly for inspection or cleaning, and where the possibility of turning the flange facilitates alignment. The flange itself not being in contact with the process fluid, it can be made of expensive carbon steel, while the flange is made of more noble material.