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r C� SAFETY AND HANDLING ANHYDROUS AMMONIA HANDLING EQUIPMENT— Because anhydrous ammonia is a liquified gas,the handling system must remain closed and under pressure to contain the product.Handling systems should be all steel,free from copper,copper alloy, aluminum or galvanized pieces.The internal trim of valves,pumps and meters must be specified as all steel. Typical piping code(consult local safety orders)requires schd.80 pipe between the tank and first shutoff valve. Above ground welded or flanged pipe larger than 1'h"size may be schd.40 beyond the shutoff valve. All other piping is to be schd.80.All steel fitting used with schd.80 pipe should be schd.80 if butt welded, 3,000 lb.WOG if socket welded and 2,000 lb.WOG if threaded.All valves and fittings must be suitable for anhydrous ammonia with a working pressure rating of at least 400 psi. Hoses should be used only for flexible transfer connections and must be specifically manufactured for NH3 and labeled with date of manufacture,working pressure and "Anhydrous Ammonia". Aping,unless protected by a pressure relief valve,should be laid out to avoid trapping liquid anhydrous ammonia between two closed valves. Welding or cutting on piping should be carried out only on systems that are completely free of ammonia vapor.Prolonged flushing and testing are the only way to assure clean lines. STORAGE—Storage tanks must be ASME Code with a 250 psig(265 psig in Calif.)working pressure.They are required to have a minimum of certain shutoff valves,relief valves,gauges and excess flow valves. fRefer to applicable codes for detail requirements. C No field welding should be made on the pressure part of any anhydrous ammonia tank.Only ASME Code welders and welding techniques should be used to repair a pressure tank.Only properly equipped shops can properly stress relieve the repaired area. MIXING— Because ammonia is under high pressure and is such a strong base,it should not be indiscriminately mixed with other materials,particularly acidic solutions.The resulting reaction can violently evolve large amounts of heat and/or gases. If such mixtures are contemplated without previous experience,technical assistance should be requested from the supplier. Anhydrous ammonia has limited application for fertilizer blends but is widely used as a straight nitrogen source.Anhydrous ammonia is used in industry for neutralization or as a chemical reactant. REFERENCE: Manufacturing Chemist's Association Chemical Safety Data Sheet SD-8 "Anhydrous Ammonia" Revised 1960 _ State of California Division of Industrial Safety Unfired Pressure Vessel Safety Orders Title 8,Subchapter 1,Article 6—Anhydrous Ammonia March 1975 Union Chemicals Division Union Oil Company of California Chemical Sales Services Department, Post Office Box 60455, Los Angeles, California 90060/(213)977-7197