U Bend Tubes

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U Bend Tubes

Pantani Divisione Tubi core business is U bend tubes for heat exchangers applied mostly in Oil & Gas plants, Chemical & Petrochemical plants, Refineries, Power plants, Renewable energy plants.

  • Copper alloys
  • Carbon steel
  • Low alloy steel
  • Stainless steel (austenitic, ferritic, super austenitic)
  • Duplex alloys (UNS S32750, UNS S32760)
  • Titanium (Gr.2, Gr.12)
  • Monel alloys
  • Nickel alloys

U bend dimension capability

Tube OD Tube thickness Bending Radius U tube straight “leg” length Straight tube before U bending
Min. 12,7mm / Max. 31,75mm Min. 0,70mm / Max. 4,19mm Min. 1,5 x OD / Max. 1250mm Max. 12500mm Max. 27000mm

Dimensional controls on U bend tube

IMG_5456 IMG_5465

– Ovalization of straight and bending portion (A-B-C-D-E-F-G)
– Thinning of straight and bending portion (A-B-C-D-E-F-G)
– Leg spacing length (I.A.1 + I.A.2)
– U bend tube length (leg + radius + (0,5 x OD))
– Difference between legs length
– Straightness of legs
– Deviation from bend plane
– Twist of bending portion
– Squareness and cleanliness of tube ends
– Complete visual check


Standards usually required to establish U bend tube tolerances:
– ASTM A556/556M
– ASTM B395 / B395M
– ASTM A688/688M
– ASTM A803/803M
– TEMA Section 5 § RCB 2.31
– DIN 28179

Post bending heat tratment by electric resistance (Joule Effect)


After U bend (cold forming), heat treatment of bending portion may be required. Pantani Divisione Tubi is equipped with 2 heat treatment machines and 1 nitrogen generating machine (to protect stainless steel tube surface during annealing). Temperature is controlled through the entire heat treated area by fixed and portable infrared pyrometers.

Post bending NDT control

Dye-Penetrant-Test IMGP0751

– Hydrostatic Test
– Air Underwater Test
– Pulsating Test
– Dye Penetrant Test
– Magnetoscopic test


IMG_5468 P1030538 AD-TUBI-B5220-019

Any type of packing is available according to customer need to worldwide destinations.