Export ASTM A312 Hot Rolled 304 / 316L Stainless Steel Seamless Pipes with RINA Certification

In shipbuilding, offshore engineering, petrochemical processing, energy equipment, seawater desalination, machinery manufacturing, and high-end fluid transportation systems, piping materials must offer not only excellent corrosion resistance and mechanical strength, but also compliance with international standards, classification society requirements, traceability rules, and project quality documentation requirements.

HAOMEI supplies ASTM A312 hot rolled stainless steel seamless pipes in TP304, TP304L, TP316, and TP316L grades, among which 304 and 316L seamless stainless steel pipes are particularly widely used. According to project requirements, our products can be supplied with classification society certification from RINA, ABS, DNV, LR, and other relevant organizations. Complete quality documentation is available, including material test certificates, dimensional inspection reports, non-destructive testing reports, hydrostatic test reports, and third-party inspection certificates. These products meet the demanding requirements of export projects, marine engineering applications, and international procurement.

Product Overview

ASTM A312 is one of the most widely recognized international standards for austenitic stainless steel seamless, welded, and heavily cold-worked welded pipes. It is suitable for high-temperature service, corrosive media, and general industrial piping systems. For projects requiring high pressure resistance, dense material structure, corrosion resistance, and long-term operating reliability, hot rolled stainless steel seamless pipes are an important piping solution due to their continuous, uniform pipe structure and excellent overall performance.

304 and 316L are two commonly used austenitic stainless steel grades. Stainless steel 304 is suitable for industrial piping systems operating in general corrosive environments. Stainless steel 316L, with the addition of molybdenum, generally provides improved resistance to pitting corrosion and crevice corrosion, making it especially suitable for chloride-containing media and selected marine industrial applications.

Our seamless pipes are manufactured from high-quality stainless steel round bars or tube billets through piercing, hot rolling, sizing, solution annealing, pickling and passivation, straightening, cutting, and inspection. The seamless structure eliminates the potential metallurgical differences and localized corrosion risks associated with welded areas, making these pipes particularly suitable for piping systems operating under high pressure, elevated temperature, cyclic loading, chloride-containing media, and marine environments.

Products can be supplied in hot rolled condition, solution annealed and pickled condition, or other special delivery conditions. We also support fixed-length cutting, beveling, end preparation, marking, bundling, export packaging, and classification society inspection services.

Chemical Composition (Typical Values, %)

Mechanical Properties (Minimum Values)

Stainless Steel Seamless Pipe Specification Range

Product Performance Advantages

1.Excellent Corrosion Resistance

304 stainless steel offers stable corrosion resistance in freshwater, atmospheric environments, and general chemical media. With 2–3% molybdenum and ultra-low carbon content of ≤0.035%, 316L provides significantly enhanced resistance to chloride-induced pitting corrosion, crevice corrosion, and weld-related intergranular corrosion. It is especially suitable for seawater-related and chloride-containing process environments.

2.High Structural Integrity of Seamless Construction

Manufactured through hot piercing and hot rolling, the pipe has no welded seam or weld-related weak point. The pipe wall structure is dense and uniform, with low residual stress. Compared with welded pipes, it offers excellent pressure-bearing capacity and resistance to cyclic loading, making it suitable for high-pressure and critical piping systems.

3.Suitable for Large-Diameter and Heavy-Wall Applications

The hot rolling process provides sufficient high-temperature plastic deformation and is suitable for the production of medium-to-large diameter and heavy-wall seamless pipes, typically in the range of 54–480 mm outside diameter and 4.5–45 mm wall thickness. Good wall thickness uniformity and surface quality can be achieved.

4.RINA Certification Support

With classification society factory approval and product inspection support, chemical composition, mechanical properties, non-destructive testing records, and solution annealing records can be fully traceable. This helps meet material compliance review requirements for international shipbuilding and offshore engineering projects.

5.Good Weldability and Machinability

The stable austenitic microstructure provides good weldability and fabrication performance. The ultra-low carbon design of 316L reduces sensitization risks in the weld heat-affected zone, facilitating on-site welding, beveling, machining, pickling, and passivation.

6.Hygienic Application Capability

When the internal surface is polished, a surface roughness of Ra ≤ 0.4 μm can be achieved, meeting cleanliness and hygienic requirements for food processing, pharmaceutical purified water, and Water for Injection (WFI) systems.

7.Full Traceability

Each pipe can be marked with a heat number for traceability. EN 10204 3.1 / 3.2 certificates and RINA certification documents can be supplied with the shipment, ensuring consistent and reliable product quality.

Main Application Fields

• Marine and Maritime Engineering (RINA-certified core applications): Piping for ocean-going cargo ships, container vessels, chemical tankers, and yachts; including engine room cooling water lines, ballast water piping, fire-fighting systems, potable water lines, heat exchanger piping, and exhaust gas cleaning system (scrubber) piping.

• Offshore Platforms and Engineering: Platform process piping, seawater transport systems, and heat exchanger piping.

• Chemical and Petrochemical Industries: Transport of corrosive media, piping connected to reaction vessels, and high-temperature process lines.

• Other Sectors: Seawater desalination, food and pharmaceutical production, high-temperature water treatment in power plants, and pressure piping for coastal infrastructure.

Export Delivery and Services

1. Packaging: Goods are packed using waterproof woven bags secured on wooden pallets or in steel frames to prevent damage or moisture exposure during ocean transit; the packaging is optimized for containerized shipping.

2. Documentation: A full set of export documents is provided with the shipment, including commercial invoices, packing lists, certificates of origin, material certificates, non-destructive testing (NDT) reports, and RINA certification documents. We also support documentation submission via Letter of Credit (L/C).

3. Customization: We offer bespoke solutions, including non-standard dimensions, specialized inspection requirements, custom marking, and tailored surface treatments. Third-party witness inspections can also be arranged to meet specific project requirements.

4. Lead Time: We maintain stock of semi-finished products for standard specifications and can rapidly schedule production for bulk orders, ensuring reliable export to countries worldwide.