How to judge whether the heating tube is good or bad:
1. Stainless steel 304 for normal water heating, stainless steel 316L for weak acid and weak alkaline liquids, and Teflon coating for strong acid and strong alkali.
2. Oil heating can be made of stainless steel 304 or iron.
3. The air heating is special, and different materials are selected according to the temperature.
(1) Stainless steel 304 is used when the working temperature is below 300 degrees;
(2) The working temperature of the air dry-burning electric heating tube is below 500 degrees using stainless steel 321 material;
(3) The working temperature of the air dry heating electric heating tube is below 800 degrees using stainless steel 310S.
3. The resistance of the two outgoing wires should be 220V normally, about 48 ohms for 1000W, about 32 ohms for 1500W, and so on.
4. The (insulation) resistance between any outlet wire and the shell is more than a few megohms. Anyone who can pass the above two steps of measurement is good.
Extended information:
How to classify the heating tube:
1. According to the cable outlet method, it can be divided into single-end electric heating tube and double-end electric heating tube.
2. According to the material classification, it can be divided into stainless steel electric heating tube, quartz electric heating tube, Teflon electric heating tube, and titanium electric heating tube.
3. According to the classification, it can be divided into straight electric heating tubes, U-shaped electric heating tubes, L-shaped electric heating tubes, W-shaped electric heating tubes, finned electric heating tubes, and special-shaped electric heating tubes.
4. According to the classification of purposes, it can be divided into dry-fired electric heating tubes and water-fired electric heating tubes.
5. According to the classification of heating methods, it can be divided into conventional resistance heating tubes and radiant electric heating tubes.
