Does anyone know the principle and models of the level switch for the heat transfer oil expansion tank?

The heat transfer oil expansion tank is a key device that serves to hold and compensate for volume changes, remove vapor, add oil, and prevent the rapid oxidation of the heat transfer oil. Thermal oil expansion tanks come in two structural forms: open and closed. (1) Systems in which the expansion tank is sealed with an inert gas (usually nitrogen) are collectively referred to as closed systems ； (2) A system in which the expansion tank is in direct contact with the atmosphere is called an open system. Due to lower manufacturing costs, as there is no need for nitrogen support facilities, such systems are widely used compared to closed expansion tanks. The expansion tank (surge tank) on the heat transfer oil furnace is used to compensate for the volume changes in the heat transfer oil due to temperature variations, thereby stabilizing the pressure of the heat carrier in the system. It also helps to remove water and air from the system; therefore, the expansion tank should be located 1.5–2 meters above the other equipment or pipes in the system. Under normal operating conditions, it should maintain a high liquid level (at two-thirds full). In the event of a sudden power outage or a failure in the heat oil circulation pump that requires an emergency shutdown of the furnace, the cold oil replacement valve can be opened. The cold oil in the surge tank then flows through the furnace tubes thanks to its gravitational potential energy, and into the oil storage tank, thus preventing the heat transfer oil inside the furnace tubes from overheating. The main functions of the expansion tank in a heat transfer oil furnace are: 1. To absorb the expansion volume of the heating medium. 2. Balance the heat transfer medium piping, exhaust, and drainage systems. 3. Safe oil top-up. 4. Prevent the oxidation and deterioration of the heat transfer medium.

Bro, you’re not answering the question~~ Hehe~~

Neither of our two heat transfer oil furnaces has this device; only an oil mist separator is available. The volume expansion of the heat transfer oil enters the high-level tank through the oil mister; when the level in the high-level tank rises above the overflow hole, the oil flows into the storage tank on the ground. As the volume decreases, heat transfer oil is automatically replenished into the circulation system from the high-level tank

It should be configured; this level switch is installed on the top side of the expansion oil tank~~to prevent a low oil level in the expansion tank from affecting the safety of the system~~

From what everyone is saying, this thing seems to be similar to an air-conditioning expansion valve (it serves to regulate flow)

I have never seen this type of level switch; when the liquid level in the high-level tank drops, the heat transfer oil from the low-level tank is pumped up to it

I’ve designed it, but I haven’t installed it yet; it would be better if I installed it, but it’s fine even without it

Your heat supply capacity is quite high~~ The high-level tank is equipped with a level gauge, right? We don’t have a level gauge; instead, we’ve installed a low-level switch~~

If it’s not installed, then it will be necessary to use a glass level gauge in the high-level tank, so pay close attention to it~~