Storage tank interlock level value
Thread Content
There is currently an internal floating roof tank, with the floating disk being 1.5 meters above the ground level. The interlock value for shutting down the discharge valve is also 1.5 meters. What should be the low-low liquid level alarm value? (No specific provisions are given in the Design Code for Tank Areas in Petrochemical Storage and Transportation Systems, SHT3007-2014.)
The height that ensures the floating disk does not touch the ground is set as the low-liquid-level alarm value
The interlock value should not be lower than 1.5m
This should be calculated based on the tank diameter and the head of the extraction pump.
In accordance with GB50074-2014 \"Code for Design of Oil Storage Tanks\", 15.1.1 states that storage tanks with a capacity greater than 100 m3 shall be equipped with remote liquid level measurement instruments, and the following requirements shall be met: 4 The set height for the low liquid level alarm in storage tanks should ensure that cavitation does not occur in the pumps. For external floating roof tanks and internal floating roof tanks, the set height for the low liquid level alarm (measured from the bottom of the tank) should be at least 0.2 m higher than the height at which the floating roof touches the bottom of the tank.
Bracket height +0.2 meters; no cavitation in the pump over 10–15 minutes