ASTM A312 TP 347 Seamless Pipes

ASTM A312 TP 347 Seamless Pipes

ASTM A312 TP 347 Seamless Pipes are niobium (columbium) stabilized austenitic stainless steel pipes designed to resist intergranular corrosion after exposure to high temperatures. Manufactured without welded seams, these pipes ensure superior strength and structural integrity.

Grade 347 contains niobium, which stabilizes the material by preventing chromium carbide precipitation, making it highly suitable for welded structures and elevated temperature service conditions.

Specifications

Standard	ASTM A312 / ASME SA312
Grade	TP 347
Manufacturing Process	Hot Rolled / Cold Drawn Seamless
Size Range	1/8" NB to 24" NB
Wall Thickness	Schedule 5S to Schedule XXS
Length	6 Meters Standard / Custom Length
Surface Finish	Annealed & Pickled, Polished, Bright Finish
End Type	Plain End, Beveled End, Threaded

Key Benefits

• Intergranular Corrosion Resistance: Niobium stabilization prevents carbide precipitation.
• High-Temperature Strength: Suitable for elevated temperature applications.
• Excellent Weldability: Maintains corrosion resistance after welding.
• Good Oxidation Resistance: Performs reliably in heat-exposed environments.
• Strong Mechanical Properties: Seamless construction ensures durability under pressure.

Chemical Composition (Typical)

Element	347 (%)
Carbon	0.08 Max
Chromium	17.0 – 19.0
Nickel	9.0 – 13.0
Niobium (Cb)	10 x C Min

Applications

• Heat Exchangers
• Boilers and Pressure Vessels
• Petrochemical Processing Units
• Oil & Gas Industry
• Power Generation Plants
• High-Temperature Piping Systems

Quality Testing

• Hydrostatic Testing
• Ultrasonic Testing (UT)
• Radiographic Testing (RT)
• PMI Testing
• Dimensional Inspection

Conclusion

ASTM A312 TP 347 Seamless Pipes provide excellent resistance to intergranular corrosion and dependable performance in high-temperature industrial environments. Their niobium-stabilized composition and seamless construction ensure long-term durability and reliability in critical piping systems.