Spiral SAW Pipe
Spiral SAW Pipe,also known as SSAW or Helical SAW(HSAW)Pipe,is a high-integrity welded steel tubular product fabricated by forming hot-rolled steel coils at a continuous helical angle and welding the seam with the submerged arc welding proc...
Spiral SAW Pipe,also known as SSAW or Helical SAW(HSAW)Pipe,is a high-integrity welded steel tubular product fabricated by forming hot-rolled steel coils at a continuous helical angle and welding the seam with the submerged arc welding process(arc hidden under a layer of granular flux).This unique spiral forming and simultaneous double-sided(internal&external)SAW welding differentiate it from longitudinal SAW(LSAW)and electric resistance welded(ERW)pipes,delivering outstanding structural strength,cost-effectiveness for large diameters,and flexible production capabilities.
Manufacturing Process
Material Inspection&Preparation:Hot-rolled steel strips,welding wire,and flux undergo strict chemical and mechanical testing;the strip is leveled,cleaned,edge-trimmed,and pre-bent.
Helical Forming:The strip is continuously formed into a cylindrical shape at a controlled spiral angle(forming angle)by a series of rolls.
Submerged Arc Welding:Simultaneous single/double-wire SAW on both inner and outer seams,with flux shielding the molten metal to prevent atmospheric contamination,ensuring deep penetration and uniform weld quality.
Post-Weld Processing&Quality Control:Heat treatment(if required),90%hydrostatic pressure testing,ultrasonic testing(UT),radiographic testing(RT),dimensional verification,and surface coating(3LPE,FBE,coal tar enamel,galvanization,etc.).
Key Specifications&Standards
Dimensions:OD typically 219 mm–3500 mm;wall thickness 5 mm–25 mm(customizable);lengths:single random,double random,or fixed lengths up to 12 m/18 m.
Materials&Grades:API 5L Grade B,X42,X52,X60,X65,X70;EN S235,S275,S355;carbon steel and low-alloy steel.
International Standards:API 5L,ASTM A252,ASTM A53,EN 10219,ISO 3183,GOST 23165.
Core Advantages
Cost-Effective Large Diameters:Narrow steel coils can produce very large-diameter pipes,reducing material waste and procurement costs compared to plate-based LSAW pipes.
Uniform Stress Distribution:The spiral weld disperses hoop and axial stresses more evenly(stress levels~75–90%of straight-seam pipes),enhancing pressure resistance and fatigue life,ideal for uneven terrain pipelines.
Production Flexibility:Adjusting the forming angle allows the same-width strip to make multiple pipe diameters,supporting small-batch,multi-spec orders.
High-Quality Welds:SAW ensures deep,consistent fusion;non-destructive testing(UT/RT)and hydro testing guarantee leak-tightness and structural reliability.
Applications
Energy Transmission:Long-distance oil,natural gas,and refined product pipelines;offshore and onshore gathering lines.
Municipal&Water Projects:Water supply,sewage,and stormwater pipelines;desalination plants.
Structural Engineering:Piling pipes for bridges,ports,and high-rise foundations;casing for tunnels;structural columns.
Industrial Uses:Slurry pipelines,power plant cooling water pipes,chemical plant process lines.
