| High-pressure fluid or gas service | Seamless pipe has no longitudinal weld seam, which can be advantageous where eliminating that seam is a design or inspection preference. | ASTM A106/A106M seamless carbon steel pipe is specified for high-temperature service. | Pressure capacity depends on material grade, outside diameter, wall thickness, temperature, manufacturing tolerances, and the applicable design code. Seamless construction alone does not determine the allowable pressure. |
| Elevated-temperature process lines | A seamless product made from a suitable grade can be used in high-temperature piping applications where the material retains the required mechanical properties. | ASTM A106/A106M covers seamless carbon steel pipe for high-temperature service. | Check design temperature, oxidation and corrosion conditions, creep considerations where applicable, and the piping code. Select the grade and wall thickness for the actual service. |
| Low-temperature service | Seamless pipe can be specified when the selected material and product specification meet the required low-temperature toughness and impact-testing requirements. | ASTM A333/A333M covers seamless and welded steel pipe intended for low-temperature service. | Confirm the required grade, minimum design temperature, impact-test requirements, and applicable code. Seamless construction does not by itself guarantee low-temperature toughness. |
| Corrosive process fluids | Seamless pipe is available in corrosion-resistant alloys and can avoid a longitudinal weld seam, but corrosion performance is primarily determined by material selection and operating conditions. | ASTM A312/A312M covers seamless, welded, and heavily cold-worked austenitic stainless steel pipe. | Evaluate the fluid composition, concentration, temperature, pressure, contaminants, and corrosion mechanism. Choose an alloy based on compatibility; stainless steel is not resistant to every environment. |
| Systems with demanding inspection or fabrication requirements | Removing the longitudinal seam can simplify some seam-specific inspection and fabrication considerations, depending on the project specification. | Product specifications and project requirements determine the permitted manufacturing route and inspection scope. | Seamless pipe still requires the inspections, testing, traceability, and acceptance criteria specified by the applicable standard and project documents. |
| General-purpose pipeline service | Seamless pipe is one available manufacturing option; it may be selected when required by the specification or preferred for a particular application. | API Specification 5L includes requirements for both seamless and welded line pipe. | Compare the approved manufacturing options, grade, dimensions, delivery condition, inspection requirements, availability, and total installed cost. Welded pipe can also be suitable when it meets the governing requirements. |