+Tank side display

We use the E+H RIA series; it’s not very useful – it’s only meant to make it easier for the people on site to see the numbers. What’s the point of having those people look at the numbers on the gauge? It’s better to directly compare the magnetic flip switch with the central control system – what’s the use of looking at the same readings on both the field device and the DCS?

What you say is correct, but due to regulatory requirements as well as expert advice, it still needs to be added. It was actually proposed by human nature-based management. In general, tank areas still use gauge reading as the primary basis for measurement.

Just install a secondary meter; brands like Hongrun and Changhui will work fine

I just added a digital display next to the tank; when the expert gave suggestions, I followed their instructions.

Just do a search on Baidu and you’ll find out that there are many types of display units for filling stations. In my opinion, as long as they have an explosion-proof certification, that’s sufficient

Is it necessary to equip the level gauges in the storage and transportation tank area with on-tank indicators? A: According to 5.3.5.1 of SHT3184, radar level gauges, servo level gauges, and magnetostrictive level gauges should be equipped with on-tank indicators as instruments for on-site monitoring of liquid levels. However, considering that the liquid levels in the tank area are usually set at two levels, and since it is possible to monitor the level right below the storage tanks, I personally believe there is no need for an indicator gauge next to the tank for those levels. As for how to construct the indicator next to the tank, refer to diagrams such as HGT21581 and SHT3007.

Standard 3184-2017 also specifies in 4.2 Instrumentation schemes for storage tanks: 4.2.1 Measurement for atmospheric and low-pressure storage tanks. 4.2.1.1 Storage tanks with a volume greater than 100 m3 shall be equipped with continuous level measurement instruments at the top of the tank; for tanks with a volume of at least 1×105 m3, it is advisable to install two such sets. The continuous level measurement instruments shall be accompanied by indicator devices mounted beside the tank to display the level, and high and low level alarms shall be provided in the control system. 4.2.1.2 High-high and low-low liquid level alarms as well as interlocks should be installed in the control system in accordance with the process requirements. The measuring instruments used for these signals should be installed separately; continuous measuring instruments are preferred, but level switches can also be used ； This is the current situation of our company: the existing methods for level monitoring are radar level gauges and high/low level switches; therefore, a display unit needs to be installed next to the tank

This post was last edited by sun_fm on 2023-1-4 at 13:22. The price of an indicator device placed next to a tank is around 17,000; the price of a fork switch is around 6,000. Float switches are even cheaper (~4,000). If a fork switch is used, an electrical cable (24VDC/220V AC) is also required. Assuming a distance of 300 meters, the cost of the cable plus installation is estimated to be between 2,500 and 3,000. Therefore, instead of choosing 1 continuous switch plus 2 fork switches, it would be better to opt for 2 continuous level gauges. Of course, there is a significant price difference among these continuous level gauges, such as those with double flanges/single flanges/ERS + radar/servo, etc. Personally, I believe that in the field of process safety engineering (PHA), without any additional requirements such as IPL – which includes alarms and personnel response, DCS control, DCS interlocks, and SIS – it is better to use two consecutive measurement methods (usually radar and differential pressure) from the perspectives of cost, reliability, and level comparison.

Just buy any display gauge and install it

During inspections, it is a very traditional requirement – and one that should be upheld – to compare the values of remote instruments with those of local instruments. However, as factory sizes grow larger, the workload for operators in the control room increases, and it becomes impractical to use walkie-talkies to check the clocks one by one. Therefore, it is necessary to digitize remote instruments and display the readings locally, comparing them with local displays such as magnetic flap level gauges, in order to avoid false readings resulting from the failure of local or remote instruments, which could lead to accidents.