Materials and grades we supply

The table lists the material families we supply in seamless form, with the product standard that normally governs each one. Follow the links for grades, sizes and technical data.

Popular grade pages include SS 304 pipes, SS 316 pipes, ASTM A106 Grade B pipes, API 5L line pipes, ASTM A335 P91 pipes, A335 P11 and P22 pipes and Inconel 625 pipes and tubes.

Types of seamless tubes

Besides process pipe, we supply seamless tubes for specific duties:

• Heat exchanger tubes – straight and U-bent tubes for shell-and-tube exchangers, condensers and coolers.
• Boiler tubes – carbon and alloy steel tubes for boilers and superheaters, supplied with IBR certification where required.
• Instrumentation tubes – small-bore stainless tubes for impulse lines and hydraulic systems.
• Capillary tubes – very small OD tubes for instruments, sensors and medical and laboratory equipment.

Sizes, schedules and standards

Sizes and schedules describe what the standards cover and what can be supplied on order. Tell us the NPS or OD, schedule or wall thickness, length and quantity, and we will confirm availability. The pipe schedule chart lists outside diameters and wall thicknesses by size.

How seamless pipe is made and checked

Mills produce seamless pipe by piercing a heated solid billet to form a hollow shell, which is then rolled or extruded to size. Smaller and thin-wall sizes are often cold drawn or cold pilgered afterwards for closer tolerances and a smoother surface. Stainless and nickel alloy pipe is then solution annealed and pickled.

Each product standard sets the tests the mill must carry out, typically chemical analysis, tensile testing, flattening or flaring tests, and a hydrostatic or non-destructive electric test. We check material against the mill test certificate (MTC) and the order before dispatch, and third-party inspection can be arranged on request. Pipes are marked with the standard, grade, size, schedule and heat number, and packed with end caps for transport.

Choosing a seamless pipe grade

The service conditions usually point to a material family. Austenitic stainless steel such as 316L is a common choice for corrosive process fluids. Carbon steel A106 Grade B is widely used for hydrocarbons and steam at moderate and elevated temperatures, while A333 Grade 6 is impact tested for low-temperature lines down to about −45 °C. Chrome-moly pipe to ASTM A335, such as P11, P22 or P91, is chosen for high-temperature steam and furnace lines. Duplex and super duplex steels suit chloride-bearing water and offshore duties, and nickel alloys handle the most aggressive chemicals and the highest temperatures. Your design code and corrosion engineer make the final selection; we then match the grade, schedule and testing to the order.

Applications

Seamless pipes and tubes are used in oil and gas production and refining, petrochemical and chemical plants, power generation, fertiliser plants, pharmaceutical and food processing lines, marine systems and engineering projects. Typical duties include high-pressure steam lines, hydrocarbon process piping, boiler and superheater tubing, heat-exchanger bundles and instrument tubing.

Seamless pipes are normally ordered with matching butt-weld and forged pipe fittings and flanges. Where a welded product meets the design code, welded pipes and tubes are an alternative in larger sizes. Every product form is listed on the products page.