Who is familiar with the interlock regulations for storage tanks? Where can I find the specific requirements?
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1. For spherical tanks, a high liquid level interlock is required; but is it also necessary to have a low liquid level interlock as well as a pressure interlock? 2. Do dome tanks require high and low liquid level interlocks? 3. Do internal floating roof tanks require high and low liquid level interlocks? 4. Do external floating roof tanks require high and low liquid level interlocks? By \"interlock\" here, we mean a mechanism that shuts off the valves in order to stop material inflow and outflow. How is this implemented in practice? I would appreciate some guidance from those with experience, or any existing regulations on this matter.
SHT3184-2017 Design Specifications for Automation Systems in Petrochemical Tank Farms – this specification should contain it
The relevant instructions found, as mentioned above. For everyone to share
There should be high and low level alarms, as well as interlocks for high-high and low-low conditions. If flammable media are involved, a positive pressure alarm as well as a flammable gas alarm is required ； Toxic media also require gas alarms. . . From a safety perspective, the feed should not be filled to capacity, the discharge should not be emptied completely, air should not enter the tank, and the medium should not leak out. . .
- -! ! ! Both low-low interlock and high-high interlock are definitely necessary; otherwise, problems will occur if there is a vacuum or overfilling.
As specified in the diagram below, only the inlet shut-off valve for high liquid level interlock is specified, while no provision is made for low liquid level interlock. Not to mention the pressure interlock; I’m still not quite sure about that.
Pressure storage tanks as specified in SH/T3184-2007