One of the routine procedures at a fuel storage tank farm is the periodic draining of water which accumulates at the bottom of the storage tanks.
The water is an undesireable element in the tanks because of the damage it may cause, such as:
- Corrosion of the tank floor and base, which may reach a degree of perforation that would permit fuel to seep into the ground.
- Development of bacteria (particularly in kerosene and jet fuel), which contaminate the
- fuel and clog the filters.
- Occupying storage space intended for storing fuel.
- Draining is done manually, requiring the constant attendance of the operator in order to prevent fuel spills. Still, despite this constant attendance, spills do occur as a result of human error and of the difficulty to distinguish between fuel and water, especially where white products are involved.
The damages fuel spills cause are:
- Environmental pollution.
- Waste of product - and of money.
- Need for intensive treatment of effluence.
- Fire hazard.
- Waste of manpower.
- Inconveniece to operator when job is done in rough environmental conditions (heat, cold, rain, wind etc.)
The use of Separation Valves prevents fuel spills and the damages listed above and saves the manpower required for the constant attendance on the manual draining process. With a Separation Valve the draining process is automatically terminated when all water has drained out.
In floating roof storage tanks, where no devices like the Separation Valve are used, accumulated rain water is drained by means of a flexible or articulated tube. On one end the tube connects to the center of the roof (A on Fig.5). It then runs through the storage tank and its other end connects to a draining outlet on the tank wall (B), which is equipped with a manual drain valve.
By regulation, the drain valve is turned on only when it rains, and must be turned off as soon as it stops raining. No doubt, observing such regulation entails great investment of manpower and labour. Furthermore, in case of fuel leak due to failure in the draining tube, great damage will occur by way of environmental pollution, loss of product and hazard of conflagration.
Using a Type TOR Separation Valve prevents the danager of fuel spill and eliminates the need to manually turn on and off draining valves during the entire year, rainy season included. The Type TOR Separation Valve is a Normally Open device, which means that it will remain open as long as it contains water, but will automatically close as soon as fuel reaches it.