Selection of level switches for interlocking in pressurized spherical tanks (2000 M3)
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Currently, level switches represent a significant challenge in the selection of instruments for spherical tanks. There are two prevailing opinions on this matter: 1) external ultrasonic level switches, and 2) contact-type fork-type level switches. In my view, each type has its advantages and disadvantages. Advantages of external level switches include 1) no need for flange openings for installation, and the position can be changed as desired. Disadvantages include 1) some people believe that the magnets and adhesives used in external level switches are not stable, and they may fall off over time. Advantages of the fork-type level switch: 1. Flange-based installation (an inclination angle must be left for installation), which makes it relatively reliable. Disadvantages: 2. It requires an opening in the pressure vessel, and once the location is determined, it cannot be changed. Please share your opinions on which option is more suitable.
If I had to choose, it would definitely be the fork-type level switch – it’s an amazing device! Another option could be to say “it’s not anything” (just a joke, of course)! When designing the spherical tank foundation or in the final design phase, if it is necessary to measure high and low liquid level alarms, openings are created for this purpose. Unless no opening is provided from the start, an external-mounted level gauge has to be used.
When designing the spherical tank, interfaces for instruments need to be provided, which is why a tuning fork is used. There are also storage tanks that don’t require level gauges; later on, I remembered I needed one but there was no interface? It’s unlikely. If an external type is to be used, an external-level gauge is more reliable; it is widely used in applications such as ammonia tanks and spherical tanks.
This device is mainly used for SIS interlock purposes, not for alarm functions. If only alarms are required, the analog alarm signals generated by the radar and servo systems are more than sufficient to meet the needs
Which tank does not require a level gauge? All large tanks have level measurements; is it necessary to use a rod for measuring the level every time? The main topic of discussion is the level switch issue for spherical tanks.
I’m just asking which one is better. In terms of practical application, in our design institute we have two main approaches for designing spherical tanks with SIS interlocks; there’s also another method that involves using a level gauge along with relay outputs, without a separate level switch. I’d like to know which approach is the best, or which one is more commonly used in practical applications
It has to be a tuning fork switch! If you’re going to use it, make sure it’s a technology that is mature and reliable!