Round-bend, square-bend, and saddle-clamp U-bolts for pipe-rack support in chloride and sour service
A pipe-rack on a topside platform, a desalination piping spool, or a process-plant elevated rack uses dozens of U-bolts per kilometre to secure the pipework to the structural support. The U-bolt sees its harshest service near the bend radius, where residual cold-work stress combines with crevice exposure between the bolt and the pipe OD. Galvanised carbon steel U-bolts fail by red rust in months of marine service; 316 austenitic U-bolts pit at chloride concentrations above 200 ppm. Ferralium 255 (UNS S32550) U-bolts hold across the asset lifetime in seawater and CO2-rich service, with PREN ≥ 40 chloride-pitting resistance and NACE MR0175 sour-service stamp on the per-heat MTC. RFQ: info@torqbolt.com / WhatsApp +91-22-66157017.
| Pattern | Pipe size envelope | Use case |
|---|---|---|
| Round-bend (semicircle) | 1/2" NPS to 24" NPS | Pipe support, hold-down across cradle saddle |
| Square-bend (right-angle) | 1" to 12" rectangular sections | Tube and structural-section clamping |
| Long-tangent round-bend | 1/2" to 24" | Where extra thread above the bend is needed for a thicker support |
| Saddle-clamp U-bolt set | 2" to 36" OD | Heavy pipe-rack with cushioned saddle, clamp-down assembly |
| Custom radius forged U-bolt | Per drawing | Non-standard OD or asymmetric clamp geometry |
Super duplex bar bent below a centreline radius of 4D (four times the bar diameter) accumulates cold work above the 5 percent strain threshold that triggers re-solution annealing per ASTM A479. TorqBolt forms U-bolts to a centreline radius matched to the pipe OD plus a clearance allowance, then re-solution-anneals at 1080 °C and water-quenches the assembly to restore ferrite content within the 35 to 55% qualifying band. The hardness traverse on the MTC documents three locations: tangent leg, bend crown, and threaded portion, each verified ≤ 32 HRC for NACE MR0175.
