By definition, seamless means “perfectly consistent”. However, many people confuse the terms “seam-free” and “welded-and-drawn” when it comes to selecting tube. Seamless tubing, welded tubing and seam-free tubing all appear to be consistently free of seams. However, a closer look reveals significant differences. We will discuss the differences between these types of stainless steel tubing.
Stainless Steel Tubing and Instrumentation
Round Stainless Tube
Stainless Steel Round Tubing is common for structural purposes and applications that range from aesthetic to highly functional.
Stainless tubing provides good corrosion resistance, weldability, machinability and can be easily cleaned and sterilized.
Seamless Tube vs. Welded Tube
Seamless tube is extruded and drawn from a billet. However, welded tube is produced from a strip that is roll formed and welded to produce a tube.
Welded tube is generally less expensive than seamless tube and is readily available in long continuous lengths. Typically, welded tubes go through a debarring process that removes the welded tube a smoother, almost brushed finish look.
Tube vs. Pipe
Tubes are structural. They are common for structural purposes and utilize outside diameter (OD) measurements.
Conversely, pipes are passageways. Pipes are common to transport gases or fluids and utilize the inside diameter (ID) measurements.
Applications of Seamless Tubes
Specific extreme applications will determine the needs for seamless high pressure tubing. In addition, it will discourage the use of welded tube because the designers can’t risk the chance for defect. Major seamless applications consists of the following:
- control lines for sub-sea safety valves for the oil and gas industry
- hydraulic controls for shipbuilding and fuel and hydraulic lines for aerospace
- heat trace bundles for chemical processing.
Welded tubing may be specified for applications within the medical device, automotive and appliance industries. While seam-free tubing is a common substitute for seamless tubing in some applications, the products are not always interchangeable. Also, this type of corrosion resistant tubing is the preferable choice in high-pressure applications.
Quality of Seamless Tubes
Quality is critical when selecting a type of tube. It is important to consider aspects such as the raw material used, production process and integrity of the mill. Also, raw material should be the highest quality.
Bryan Hose & Gasket is a reputable tubing supplier that fully documents our certifications and exceed ISO 9001 requirements. Additionally, our systems extend to the manufacturing process and allow for quality checks throughout the production of our products.
There are numerous differences between seamless, welded and welded-and-drawn stainless steel tubing. These include complexity of the manufacturing process, cost of the finished product, opportunity for defect and pressure rating. If you are still have questions or are looking to purchase seamless tubing, don’t hesitate to contact us here at Bryan Hose & Gasket with the link below!