ASTM A182 F321 Lap Joint Flange LTF Flange EN 1.4541 / 08Х18Н10Т Stainless Steel Flanges

ASTM A182 F321 / UNS S32100 / 1.4541 Stainless Steel Lapped Flange Lap Joint Flange

ASTM A182 F321 Lap Joint Flange (LTF) is a forged stainless steel pipe-connecting component consisting of two separate, non-integral pieces:

1. The Flange Ring (Loose Flange) – Manufactured to ASTM A182 F321, this ring slides freely over the pipe.

2. The Lap Joint Stub End – A separate piece, typically manufactured to ASTM A403 WP321 or equivalent, which is butt-welded to the pipe end and features a radiused shoulder that mates with the back face of the loose flange.

When bolted to another flange, the pressure from the bolts compresses the stub end's gasket surface against the opposing flange, while the loose ring transmits the bolting load. The flange ring itself never contacts the process fluid – only the stub end does. This design allows the ring to rotate freely around the pipe, making bolt-hole alignment effortless during assembly.

Chemical Composition of ASTM A182 F321 Lap Joint Flange EN 1.4541 / UNS S32100 Stainless Steel Flanges 

Mechanical Properties of ASTM A182 F321 Lap Joint Flange EN 1.4541 / UNS S32100 Stainless Steel Flanges

Applications

Due to its titanium stabilization and easy-assembly design, this LTF Flange combination is widely used in:

• Low to Medium Pressure Piping Systems (Class 150 – 300).

• Heat Exchanger and Vessel Nozzles where frequent disassembly is required for internal cleaning.

• Food Processing & Pharmaceutical (where easy dismantling and sanitation are critical).

• Chemical Plants handling oxidizing acids (e.g., nitric acid) at moderate temperatures.

• Cryogenic Services – F321 retains good toughness at sub-zero temperatures.