The so-called “people rely on clothes and saddles” means that what kind of clothes a person wears will reflect a person’s taste, and what kind of saddle is used to ride a horse will have a different effect. The same applies to the appearance of musical instruments. A high-performance appearance, on the surface, should reflect its extraordinary quality. Today we will take the level switch as an example to talk about the protective coating on the surface of the instrument. Why choose the level switch? the reason is simple.Because the medium measured by the liquid level switch is liquid, it means that the appearance quality must be high, and the appearance itself must have a high degree of compactness. When the exterior is immersed in a dangerous liquid, the outer shell must have excellent corrosion resistance, oxidation resistance, high temperature resistance, etc., to ensure that the exterior can operate normally and smoothly without being affected by the external environment.However, the medium measured by the liquid level switch and the liquid level gauge is mainly solid material. Compared with the liquid medium, the external environmental threat index of its casing is lower, so the casing quality of the liquid level switch is more and more able to check the appearance quality.As far as the liquid level switch is concerned, the protective coating of its shell is very complicated. This is because the types of media to be measured in the field application of the liquid level switch are more diverse, including many highly corrosive media, such as strong acids and alkalis.In order to prevent corrosion of the liquid level switch, some manufacturers usually add a certain protective coating to the position where the liquid level switch contacts the medium according to the characteristics of the medium to improve the anti-corrosion ability of the liquid level switch, thereby extending the service life and product reliability of the liquid level switch sex.There are many protective coatings that can be applied to liquid level switches. Among them, PFA coating, ECTFE coating and glaze coating are the three most commonly used protective coatings.1. PFA coatingPFA coating and ECTFE coating are both Teflon raw materials, but the difference is that PFA coating is more resistant to high temperature and steel is more tough, so it is widely used in corrosive media. The sintering temperature of PFA coating is 380~400, and the continuous working temperature is as high as 260, so it is often applied to the side of high temperature liquid level switch to improve its corrosion resistance. However, compared with other coatings, the PFA coating process is more difficult and the price is relatively high.Second, ECTFE coatingECTFE coating is similar to PFA coating, both of which are excellent corrosion-resistant materials. The sintering temperature is lower than that of the PFOS coating, which is 250-270.Its advantage is that the processing difficulty is low, and the processing is relatively simple compared with PFA coating, but its continuous working temperature (medium temperature or process temperature) is lower than PFA coating, as long as it is lower than 150, so it is usually only used for normal temperature liquid level switches protection of.Third, the glaze coatingGlaze coating is also called enamel. The sintering temperature of this protective coating is very high, and the corresponding process is also very difficult.
Generally, the metal surface is uniformly coated with the required material and sintered at high temperature. The glaze is smooth and delicate, not easy to crack and fall off, good combination, high temperature resistance and corrosion resistance. It can be seen from the above that the three coatings have their own advantages and disadvantages. The detailed choice of which coating to use on the level switch usually depends on the field application conditions and customer requirements.
Post time: 21-09-21