ASME SA-268 pdf free download

ASME SA-268-2021 pdf free download.Standard Specification for Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing for General Service.
12. Permissible Variations in Dimensions
12.1 Variations in outside diameter, wall thickness, and length from those specified shall not exceed the amounts prescribed in Table 6.
12.2 The permissible variations in outside diameter given in Table 6 are not sufficient to provide for ovality in thin-walled tubes, as defined in the Table. In such tubes, the maximum and minimum diameters at any cross section shall deviate from the nominal diameter by no more than twice the permissible variation in outside diameter given in Table 6; however, the mean diameter at that cross section must still be within the given permissible variation.
12.3 When the specified wall is 2 % or less of the specified outside diameter, the method of measurement is in accordance with the agreement between the purchaser and the manufacturer (see Note 1).
Nm I —Very thin wall tubing may not he stiR’ cnough for the outside diameter to be accurately measured with a point contact test method, such as with the USC of a micrometer or caliper. When very thin walls are specified, “go”-”no go” mg gages are commonly used to measure diameters of 1½ in. 138.1 rnml or less, AO,002-in. IO.05-mml additional tolerance is usually added on the “go” ring gage to allow clearance for sliding. On larger diameters, measurement is commonly performed with a pi tape. Other test methods such as optical test methods may also be considered.
13. Surface Condition
I 3. I All tubes shall be free of excessive mill scale, suitable frr inspection. A slight amount of oxidation will not he considered as scale. Any special finish requirements shall be subject to agreement between the manufacturer and the purchaser.
14. Mechanical Tests Required
14.1 Tension Tests—One tension test shall be made on a specimen for lots of not more than 50 tubes. Tension tests shall be made Ofl specimens from two tubes for lots of more than 50 tubes.
14.2 Flaring Test (for Seamless Tubes)—- One test shall be made on specimens from one end of one tube from each lot of finished tubes. The minimum expansion of the inside diameter shall be 10 %. For tubes over 8 in. 1203.2 mml in outside diameter, or tubes with wall thickness in. [9.52 mml and over, the flattening test may be performed instead of the flaring test unless the flaring test is specified in the purchase order.
14.3 Flange Test (for Welded Tubes)— One test shall he made on specimens from one end of one tube from each lot of finished tubes. For tubes over 8 in. [203.2 mini in outside diameter, or tubes with wall thickness ¾ in. 19.52 mml and over, the flattening test may be peribrined instead of the flange test unless the flange test is specified in the purchase order.
14.4 Hardness Tesr—Brinell or Rockwell hardness tests shall be made on specimens from two tubes from each lot.
14.5 When more than one heat is involved, the tension, flaring, flanging, and hardness test requirements shall apply to each heat.
14.6 Reverse Flattening Test—For welded tubes, one reverse flattening test shall be made on a specimen from each 15(X) ft [450 ml of finished tubing.ASME SA-268 pdf download.