What Are Seamless Pipes?
Per ASTM A106 and API 5L, seamless steel pipes are made by hot-piercing a solid billet on a Mannesmann rotary piercer — no longitudinal weld seam, so they are inherently stronger under pressure and temperature than welded pipes. They are specified for refinery process piping, oil & gas transmission, chemical plants, and high-pressure structural service. Ordered by nominal pipe size (NPS) and schedule per ASME B36.10.
- No weld seam — uniform strength in all directions
- Suitable for high-pressure, high-temperature, and cyclic-load service
- Available in Schedules 40, 80, 120, 160, and XXS
- IBR-approved grades available for steam and boiler feed piping
Specifications We Stock
| Nominal Pipe Size (NPS) | 1/2" to 24" (15 NB to 600 NB) |
|---|---|
| Wall Thickness | Schedule 40, 80, 120, 160, XXS (2 mm to 60 mm) |
| Grades | ASTM A106 Gr A/B/C, API 5L Gr B to X70, ASTM A53 Type S, IS 6286 |
| Lengths | Single Random (SRL) 5–7 m, Double Random (DRL) 9–13 m, or cut-to-length |
| End Finish | Plain, beveled (30°), threaded, or with couplings |
Common Applications
- Oil & Gas: Transmission pipelines, gathering lines, and process piping.
- Refineries & Petrochemical: High-temperature process piping and steam distribution.
- Chemical Processing: Corrosive fluid transport and reactor feed lines.
- Power Generation: Boiler feed piping, main steam lines, and auxiliary systems.
Source Mills We Work With
We procure materials exclusively from highly reputed Indian and global steel mills, including:
Maharashtra Seamless Limited (MSL)Jindal Saw LtdISMT LimitedTenarisRatnamani
How To Order
- Specify NPS (nominal pipe size) and schedule or exact OD and wall thickness.
- State the grade: ASTM A106 Gr B is the most common; API 5L for line-pipe applications.
- Indicate end finish (plain, beveled, threaded), quantity (meters or MT), and MTC requirement.
- Confirm if IBR Form III-C or sour-service (NACE MR0175) compliance is needed.
Frequently Asked Questions
What is the difference between seamless steel pipes and seamless boiler tubes?
Seamless steel pipes are ordered by NPS and schedule for fluid transport and pressure piping (ASTM A106, API 5L). Seamless boiler tubes are ordered by OD and wall for heat-transfer duty in boilers and heat exchangers (SA192, SA210, SA213). Different products, different buyers, different specifications.
Which grade of seamless pipe is most commonly ordered?
ASTM A106 Grade B is the workhorse grade for refinery and power-plant service up to ~425 °C. For oil & gas transmission, API 5L Grade B to X65 PSL2 is standard. For general utility, ASTM A53 Type S Grade B covers non-critical pressure and structural applications.
Can seamless pipes be supplied with IBR certification?
Yes. ASTM A106 (SA-106) is an IBR-approved specification. We supply seamless pipes with Form III-C certification from IBR-recognised inspecting authorities for boiler feed, steam, and pressure piping applications.
Related
- Seamless Steel Pipes — Kanpur wholesale supply — pricing, delivery zones, and grade options for buyers in UP and North India.
- Calculate the weight of Seamless Steel Pipes for your BOQ — size, wall, and length to MT before requesting a quote.
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