across the seam, shall be 11⁄2 inches wide, edges shall be parallel and rounded with a file, and back-up strip, if used, shall be removed by machining. The specimen shall be bent to refusal in the guided bend test jig illustrated in § 78.51-22. The root of the weld (inside surface of the cylinder), shall be located away from the ram of the jig. No specimen shall show a crack or other open defect exceeding 8 inch in any direction upon completion of the test. Should this specimen fail to meet the requirements, specimens may be taken from each of two additional cylinders from the same lot and tested. If either of the latter specimens fails to meet requirements, the entire lot represented shall be rejected. An (d) Alternate guided-bend test. alternate guided-bend test jig, as illustrated in § 78.51-23 (a) and (b), may be used for testing the soundness of fillet welded lap joints and joggle butt joints. The test specimen shall be bent across the weld as illustrated in sketch A or B for fillet welded lap joints and as illustrated in sketch C or D for joggle butt joints. The specimen shall be bent until the elongation at the outer surface, adjacent to the root of the weld, between the lightly scribed gauge lines-a to b, shall be at least 20 percent; except that this percentage may be reduced for steels having a tensile strength in excess of 50,000 pounds per square inch, as provided in § 78.51-16. No tested specimen shall show a crack, or other defect, as specified in § 78.51-17 (c). The gauge lines shall be lightly scribed before bending. The amount of elongation may be conveniently determined with a Brinell microscope or any other suitable method may be employed. [15 F. R. 8372, Dec. 2, 1950, as amended by Order 1, 16 F. R. 5327, June 6, 1951] § 78.51-18 Rejected cylinders. (a) Reheat treatment authorized; subsequent thereto, acceptable cylinders must pass all prescribed tests. Repair of brazed seams by brazing and welded seams by welding is authorized. § 78.51-19 Marking. (a) Marking on each cylinder stamped as follows: (1) ICC-4BA followed by the service pressure (for example, ICC-4BA240, etc.). (2) A serial number and an identifying symbol, both to be of the purchaser, user, or maker. The symbol must be registered with the Bureau of Explosives. Duplications unauthorized. Lot numbers in place of serial numbers authorized for cylinders not over 2 inches outside diameter or for cylinders with volumetric capacity not exceeding 60 cubic inches. (3) Inspector's official mark. (4) Date of test (such as 4-50 for April 50). (5) Additional markings are permitted. (b) Sequence of marks. Number shall be just below the ICC marking; identifying symbol shall be just below the number; inspector's official mark shall be near the serial number. Date of test shall be so placed that dates of subsequent test can easily be added. Symbol in front of or following the number, with space between, or symbol and serial number stamped into welded or brazed-on valve spud directly above the ICC mark located on head or cylinder are also authorized. Other variations in sequence of marks authorized only when necessitated by lack of space. (c) Location of markings. Markings may be stamped plainly and permanently in the following locations on the clyinder: (1) On shoulders and top heads not less than 0.087 inch thick. (2) On side wall adjacent to top head for side walls not less than 0.090 inch thick. (3) On neck, valve boss, valve protection sleeve, or similar part permanently attached to top end of cylinder. (4) On a plate attached to the top of the cylinder or permanent part thereof; sufficient space must be left on the plate to provide for stamping at least six retest dates; the plate must be at least 6 inch thick and must be attached by welding, or by brazing at a temperature of at least 1100° F, throughout all edges of the plate. (5) Variations in location of markings authorized only when necessitated by lack of space. (d) Size of marks. Space permitting, at least 1/4 inch high. § 78.51-20 Authorized steel. (a) Open hearth or electric steel of uniform quality. The following chemical analyses are authorized. (See footnote 1): 1 A heat of steel made under any of the above specifications, chemical analysis of which is slightly out of the specified range, is acceptable, if satisfactory in all other respects, provided the standard permissible variations from specified chemical ranges and limits published in the American Iron and Steel Institute Products Manual, "Alloy Steel: Semifinished; Hot Rolled and Cold Finished Bars", dated July 1955, are not exceeded or are approved by the Bureau of Explosives. This designation shall not be restrictive and the commercial steel is limited in analysis shown in the table. Grain size 6 or finer according to A. S. T. M. Spec. E 19-46. Only fully killed steel authorized. [15 F. R. 8372, Dec. 2, 1950, as amended by Order 18, 20 F. R. 954, Feb. 15, 1955; Order 25, 21 F. R. 3014, May 5, 1956] The compliance of cylinders with specification requirements was verified including markings, condition of inside, tests, threads, etc. All cylinders with defects which might prove injurious were rejected. The processes of manufacture and heat treatment were supervised and found to be efficient and satisfactory. The cylinder walls were measured and the minimum thickness noted was inch. The outside diameter was determined by a close approximation to be inches. The wall stress was calculated to be --- pounds per square inch under an internal pressure of pounds per square inch. Hydrostratic tests, tensile tests of material, and other tests as prescribed in specification No. ICC-4BA were made in the presence of the inspector and all cylinders ac Steel was manufactured by. files of the manufacturer. Company. The originals of the certified mill test reports are in the NOTE: Any omission of analyses by heats, if authorized, must be accounted for by notation hereon reading "The prescribed certificate of the manufacturer of material has been secured, found satisfactory, and placed on file," or by attaching a copy of the certificate. Chemical analyses were made by NOTE: When specifications require test for only 1 out of each lot of 200 or less cylinders, the check on the others must be indicated by a notation hereon reading, "Each cylinder was subjected to a pressure of...-pounds per square inch and showed no defect." If the tests are made by a method involving the measurement of the amount of liquid forced into the cylinder by the test pressure, then the basic data, on which the calculations are made, such as the pump factors, temperature of liquid, coefficient of compressibility of liquid, etc., must also be given. Do not include removable cap but state whether with or without valve. These weights must be accurate to a tolerance of 1 percent. 3 Report approximate maximum and minimum volumetric capacity for the lot. (Signed). § 78.51-22 Guided bend test jig. (a) Dimensions as follows: NOTE: Dimensions shown for die and plunger are for " thick material only. The following dimensions shall be used for other thicknesses. Thickness of plunger member=4x thickness of test specimen. Radius of plunger member=2× thickness of test specimen. Width of opening, die member=6x thickness of test specimen+%". Radius of die member=3x thickness of test specimen +116". § 78.51-23 Alternate guided bend test jig. (a) Dimensions as follows: NOTE: Dimensions shown are suitable for bending lap-weld specimens of 0.05" to 0.133" material thickness. A piece of 2" pipe may be slipped over the mandrel for turning. For any specimen thickness, fillers of appropriate thickness shall be added to one or both sides of the specimen as shown to obtain the required elongation. |