Grades 1.4401 and 1.4404, commonly known as stainless steel grades 316 and 316L, are the second most commonly used stainless steel grade after 304/304L. 316 is basically an improved version of 304, with addition of molybdenum and slightly higher content of nickel.
Tube insert and ferrule are the products tube that is inserted into the end of a heat exchanger tube to provide a specific function. The purpose of a tube insert is to either be sacrificial to the effects of inlet-end erosion, corrosion, impingement to induce a fluid to fall on the ID of a tube in a falling film exchanger; or to transfer extremely high heat past the tube sheet to the exchanger tubes. Each of the above applications requires a specific style of design. At Arrow, we manufacture metal tube inserts for all applications, providing the necessary drawings required. Ceramics perform well when the temperatures are extremely high. However, ceramics can be subject to breaking. Unity Tube can provide many ferrules or tube inserts in a variety of materials and sizes.