ASTM A355 Gr.P9 Alloy Steel Serrated Fin Tubes What is ASTM A335 P9? ASTM A335 P9 is a seamless ferritic alloy steel pipe which is used for high temperature applications. These pipes can be used to transmit water, oil and natural gas. The key to the composition of chrome moly alloy P9 is the addition of chromium and molybdenum. Serrated Fin Tube is a high-frequency welded production process. Using high-frequency power supply as a heat source, the steel strip and steel tube are heated, so that they can be welded together. It has the characteristics of long life and high pressure tolerance. The serrations are small grooves or notches that are cut into the fin surface, which increase the turbulence of the fluid flowing over the fins. Serrated fin tubes are commonly used in applications where high thermal performance is required, such as in boilers, air-cooled condensers, and heat exchangers. Features: The oxidation is not easy to occur and the org…