ASME SA556 Seamless Feedwater Heater pipes production process

　　ASME SA556 Seamless Feedwater Heater pipes Workmanship, Finish, and Appearance Finished tubes shall be free from scale but may have a superficial oxide film on the surfaces. Alight oxide scale on the outside and inside surfaces of U-bend shall be allowed for tubes which have been heat treated.

　　Finished tubes shall be reasonably straight and have smooth ends free from burrs. Tubes shall have a workmanlike finish and shall be free of surface imperfections that cannot be removed within the allowable wall tolerances. Removal of surface imperfections such as handling marks, straightening marks, light mandrel and die marks, shallow pits, and scale pattern will not be required provided they are within the allowable wall tolerances.

　　Finished tubes shall be coated both on the outside and the inside diameter to prevent corrosion in transit. The type of coating applied should be mutually agreed upon and specified in the order.

　　The tubing will be packaged or bundled in such a manner as to prevent damage in ordinary handling and transportation and identified by a tag with the name of the manufacturer, purchase order number, specification number and grade, and size.

　　ASME SA556 Seamless Feedwater Heater pipes covers minimum-wall-thickness, seamless cold-drawn carbon steel tubes including bending into the form of U-tubes for use in tubular feedwater heaters. Mechanical tests shall be made on specimens including: tension test; flattening test; flaring test; hardness test; and hydrostatic test. Each tube shall be tested after the finish heat treatment following the final cold-drawn pass by passing through a nondestructive tester capable of detecting defects on the entire cross section of the tube.