Storage tank will be carbon steel (ASTM A537 CL1), wall thickness ≥12.7mm, design pressure ≥1.6MPa, capacity usually 30-50m³, and storage temperature stringently regulated between -33.4°C (atmospheric boiling point) and 50°C. Minimize pressure oscillations during phase changes. According to the accident analysis of the Port of Rotterdam in the Netherlands in 2021, if the tank temperature is higher than 55°C, the internal pressure will increase at a rate of 0.23MPa/°C, and the frequency of the safety valve will be 12 times/hour, which is much greater than 0.5 times/month under normal circumstances.
The security system should be equipped with two redundant pressure relief valves (1.72MPa±2%), bleed rate ≥1.2t/h (for the 50t storage tank), and a specialized leakage sensor of anhydrous ammonia gas (0.5ppm detection accuracy, response time ≤3 seconds). Measurements on data from German BASF site show that, with 6 groups of sensors within a radius of 15m, there is the capacity to reduce location error of leak point by ±0.8m, unlike single-point measurement with 75% more efficiency. Explosion-proof electrical apparatus must meet ATEX II 2G Ex db IIC T4 standards, environmental humidity measurement must be maintained <60%RH to prevent SCC, according to NACE MR0175, humidity >70% carbon steel corrosion rate will increase by 300%.
Transportation connection should use DOT-51 special tank truck, wall thickness ≥9.5mm, and is equipped with real-time GPS positioning and inertial monitoring system, speed is limited to 90km/h or less. According to the traffic accident data in California in 2020, if the tank truck speed is more than 100km/h, the emergency braking distance should be extended by 34%, and the rolover probability is as high as 17.8%. The loading and unloading process should use 316L stainless steel pipe (DN80 or larger), regulate the flow rate ≤2.5m/s, prevent electrostatic accumulation (charge density <30μC/m³), as per the Canadian Energy Agency requirement, ground resistance should be <10Ω and the crossover potential difference <50mV.
The emergency treatment facilities shall be equipped with a ring spray device (flow ≥200L/min·m), and reserve for neutralizer shall be commensurate to the storage capacity at a 1:1.2 ratio (e.g., 50t liquid ammonia shall reserve 60t 20% sulfuric acid solution). Statoil experience has shown that if the spray system start-up is delayed more than 90 seconds, the vapor cloud will spread 2.8 times the base value. Storage facilities have to be set up concrete cofferdams (height ≥0.6m, volume ≥110% of tank capacity). In the 2022 Gujarat chemical plant leak, cofferdams employed for compliance shut off 98% of leaking liquid ammonia, reducing direct economic expenses of about $23 million.
Periodical maintenance entails ultrasonic wall thickness measurement (±0.1mm accuracy), quarterly corrosion rate detection (standard requirement <0.13mm/year), and comprehensive inspection every 5 years in accordance with API 510 specifications. The operators need to undergo special training of 40 hours annually, including VR accident simulation training (83 leak conditions), and OSHA statistics indicate that systematic training can decrease the error rate during operations from 2.1‰ to 0.37‰.