Tanks dike access

Hydrants should be located on the street or roadside of all pipelines or drainage ditches to allow access for the pumper truck. Where large pipelines or drainage ditches may hinder access, access across such obstructions should be provided. Hydrants and manually operated monitors should be located outside of tank dike areas. Monitors capable of remote operation from outside tank dike areas may be located within that area. 

Phosphoms is stored and handled under a protective layer of water. Production quantities are transferred as a Hquid by either water displacement or pumps, with water recycle to maintain the water balance and cover. In earlier times, phosphoms was sometimes stored in underground tanks or pits, but as of the 1990s storage is limited to tanks located inside diked areas that are accessible on the outside for safety and leakage control. 

Diked or Unitized Secondary Containment. Small tanks can have a secondary-containment dam built integrally into the tank. This is essentially within a steel box. These tanks may be either vertically or horizontally oriented in both cylindrical and rectangular shapes. The secondary-containment dikes may be open or closed. Closing the dikes makes access to the primary-containment tank more difficult, but keeps out rainwater. 

Tanks should be grouped so that no more than two rows of tanks are provided within diked areas separated by roads to ensure fire fighting access is available. Large tanks within a common diked area should be provided with intermediate spill dikes or drainage channels between the tanks, as an intermediate level of protection against spill spread. When a small number of small tanks are located together the level of major impacts is less and therefor the financial risk is lower. In these cases it is acceptable not to provide full or intermediate dikes. 

Examples of common safe practices are pressure relief valves, vent systems, flare stacks, snuffing steam and fire water, escape hatches in explosive areas, dikes around tanks storing hazardous materials, turbine drives as spares for electrical motors in case of power failure, and others. Safety considerations are paramount in the layout of the plant, particularly isolation of especially hazardous operations and accessibility for corrective action when necessary. 

A 500-gallon permanent chemical storage tank with dike and access... 

---