Automation of terminals is a must to have safe and efficient operations. Manually planning, executing, and recording movements can greatly impact the profitability of terminal. Mistakes result in contamination, unsafe working conditions, and the loss of materials and energy. Any of these factors can directly contribute to higher operating costs, revenue loss, and, ultimately, lost opportunities.
We have tried to list out some of the common challenges encountered during design of the terminals, the areas which are missed out during engineering and the areas where we are not able conclude during engineering
Operation of valves inside the dyke
In case of emergencies such as oil spillage inside dyke it is not possible to access the valves located inside dyke. Hence it should be ensured that suitable access platforms are provided right from outside the dyke up to the valves so that person need not have to land inside the dyke to approach the ROSOVs.
Cabling inside the tank dyke
It is observed that in most of the cases the inside portion of dyke is required to be made impervious. Due to which providing structural steel support for cable trays on dyke floor is not advisable. The best practice is to avoid puncturing dyke floor and use the access platform provided for valves to support the cable trays.
Cabling for the instruments mounted on the tank
There are many instruments such as Radar level transmitter, multipoint temperature sensor, vibrating fork level switch etc. are located on tank roof. Cable tray routing and supporting for all the cables from these roof top instruments up to junction boxes located outside tank dyke is always a challenge. There are two ways to overcome this situation. First option is to use the tank staircase structure to support all the cable trays from roof top to bottom of tank. Second option is to provide mounting pads all along the body of tank from top to bottom at certain interval to support the cable trays.
Safety Integrity Level (SIL) requirement for field instruments( Radar Relay only SIL certified)
The instrument, valves, relays, control system etc. used in emergency shutdown loops shall be SIL certified. The SIL level for these items shall be ascertained after carrying out SIL identification study. If Radar level transmitters if they are used in ESD loops then the specifications shall be designed considering the following aspects.
- Very few manufacturers provide radar level transmitter with SIL rated 4-20 mA output.
- Some manufacturers provide radar level transmitter with only SIL rated one no. relay output.
- Very few manufacturers provide SIL 3 rated radar level transmitter.
- Power supply for periphery security systems.