What construction method is most commonly used for high-pressure boiler tubes?

Seamless construction is the method most commonly used for high-pressure boiler tubes due to its superior strength and ability to withstand the extreme conditions associated with high-pressure operations. Seamless tubes are manufactured from solid round steel billets that are heated and then pierced to form a hollow tube. This process eliminates any potential weaknesses that might be introduced by weld seams, which can be points of failure under high stress and temperature conditions typically found in high-pressure boilers.

The lack of weld seams in seamless tubes allows for better resistance to stress and fatigue. This makes them ideal for applications where structural integrity is critical, like in high-pressure steam systems, where the risk of failure can lead to dangerous situations. Moreover, seamless tubes typically present a uniform thickness and strength throughout their length, enhancing their performance and reliability in demanding applications.

The other construction methods, such as resistance welded, lap welded, and combination welded, can introduce stress concentrations and potential weak points, which are not acceptable in environments where high pressure can lead to catastrophic failures. Therefore, seamless tubes are the preferred choice for high-pressure boiler applications.