Safety Valves 36. (a) Free venting and effective discharge area. Every container shall be provided with one or more safety relief valves of spring-loaded or equivalent type. These valves shall be arranged to afford free vent to the outer air. The area of the discharge shall be sufficient to prevent the building up of pressures in excess of 120% of the maximum permitted setting of the safety relief valves on the container and in accordance with the provisions of the effective discharge area as specified in the following table. (b) Effective Discharge Area Required for Safety Relief Valves. (D=outside diameter of tank in feet; U overall length of tank in feet; “A”= the product of D times U). Minimum required free discharge area (square inches) when tank working pressure, in pounds per square inch, is- Where "A" does not exceed 10.. Where "A" is greater than 10 but not more than 15. Where "A" is greater than 15 but not more than 20. Where "A" is greater than 20 but not more than 40. Where "A" is greater than 40 but not more than 60. Where "A" is greater than 60 but not more than 80. Where "A" is greater than 80 but not more than 100. Where "A" is greater than 100 but not more than 120. Where "A" is greater than 120 but not more than 140. Where "A" is greater than 140 bu. not more than 160. Where "A" is greater than 160 but not more than 180. Where "A" is greater than 180 but not more than 200. Туре 80 lb. min. To be calculated using Fetterley's formula as promulgated by Bureau of Explosives, New York City. (d) Relief valves, tampering. Safety relief valves shall be so arranged that the possibility of tampering will be minimized; if pressure setting or adjustment is external, the relief valves shall be provided with approved means for sealing adjustment. (e) Relief valve installation. No shutoff valves shall be installed between the safety relief valves and the container except that a shut-off valve may be used where the arrangement of this valve is such as always to afford full required capacity flow through the relief valves. NOTE: The above exception is made to cover such cases as a three-way valve installed under two safety relief valves, each of which has the required relief valve area and is so installed as to allow either of the safety relief valves to be closed off but does not allow both safety valves to be closed off at the same time. Another exception to this may be where two separate relief valves are installed with individual shut-off valves. In this case the two shut-off valve stems shall be mechanically interconnected in a manner which will allow full required flow of one relief valve at all times. (f) Relief valve, vapor space. Safety relief valves shall have direct communication with the vapor space of the container. (g) Relief valve markings. Each container safety valve shall be plainly and permanently marked with the pressure in pounds per sq. in. gauge at which the valve is set to start to discharge and the actual free discharge area in sq. in. of the valve at its full open position; for example, 200-24. PART 4-REGULATIONS Applying PARTICULARLY TO CARRIERS BY RAIL FREIGHT (Add) 512 EXPORT SHIPMENTS VIA DOMES TIC CARRIERS BY RAIL (a) Explosives and other dangerous articles authorized to be exported from the United States when packed, marked, labeled, and described, in accordance with rules and regulations in force at destination ports, must not be accepted by any common carrier by rail for domestic transportation unless in full accordance with the regulations herein. (b) Spec. 15X: Wooden boxes with inside metal containers. For shipment via common carriers by water to noncontiguous territories or possessions of the United States and foreign countries. Authorized for rail freight transportation in carload shipments only. (c) Spec. 17X: Metal drums (single-trip). For shipment via common carriers by water to noncontiguous territories or possessions of the United States and foreign countries. Authorized for rail freight transportation in carload shipments only. (d) Spec. 17E: Metal drums (single-trip), not over 55 gallons capacity, without opening except bung hole not exceeding 2.3 inches in diameter. For shipment via common car Explosives must not be loaded together nor with other dangerous articles, except Articles shown in this section. [The following table shows the explosives and other dangerous articles which must not be loaded or these packages must not be loaded or stored together, for example: Blasting Caps (d) ho PLOSIVES AND OTHER DANGEROUS ARTICLES DLING CARS; LOADING PACKAGES INTO CARS as provided in the Loading and Storage Chart of Explosives and other Dangerous rizontal column must not be loaded or stored with High Explosives (b) vertical column] stored together. The letter X at an intersection of horizontal and vertical columns shows that 2 [The following table shows the explosives and other dangerous articles which must not be loaded or these packages must not be loaded or stored together, for example: Blasting Caps (d) ho a Blasting caps or electric blasting caps in quantities not exceeding 1,000 caps may also be loaded and transported with all articles named except those in columns b, c, e and f. Unless loaded in opposite ends of car, acids or other corrosive liquids, white label, must not be loaded with yellow label articles, ammunition for cannon with cr without projectiles, or smokeless powder. NOTE.-Charged electric storage batteries must not be loaded in the same car nor stored with any dangerous explo sive, class A. NOTE: Footnote a to the chart (5 F.R. 5089) was previously amended by Order, Mar. 31, 19 Blasting caps or electric blasting caps in quantities not exceeding 1,000 caps may be load |