The inner tank of enamel water heater originated in the United States 50 years ago. In Europe, especially Germany, the production of enamel-lined water heaters began in the 1960s, but only when the enamel-liner was combined with the male plate did it establish its position in the application field. The capacity of water heaters can be as small as 15 liters and as large as 4,000 liters. They are roughly divided into American and European styles. The main difference lies in the design of the inner tank.

my country began to use enamel liners in the production of water heaters about ten years ago. Due to its superior performance in anti-corrosion, the enamel liner gradually replaced the stainless steel liner and became the main force of the water heater liner.

To manufacture a liner that meets the standard, the design of the enamel liner is the key. After selecting the steel plate, having good welding quality suitable for enamelling is an important factor to ensure product quality. The welding seam design of the enamel liner and the deep processing accuracy of the blank body are the prerequisites to ensure the welding quality. The product with the welding seam must be coated with the enamel glaze has always been an important factor that must be adapted in the enamel process. In a sense, the quality of welding determines the quality of the product after being coated with enamel. Because of welding seam defects caused by welding, such as over-burning of the inner wall of the inner tank, there are more serious defects such as large pores, bubbles, large inclusions, cracks, unwelded, etc., as well as in the weld and heat-affected zone. Severe Widmanstatten structure will leave various enamel defects after firing of the enamel, which not only affects the corrosion resistance of the product, but also severe welding defects will directly affect the safety performance of the product.

The requirements for the welding seam of the product are: the welding seam mechanism is accurate, the shape of each part of the inner wall is reasonable, and it is suitable for the process requirements of enameling. After the enameling and firing of the enameled surface, the weld area is basically normal. With the rapid development of technology, many advanced welding technologies and processing techniques have greatly reduced the traditional weld width calculated in millimeters, so that the degree of thermal influence in the weld area is significantly reduced, and the quality of the product blank weld is more suitable for the current Kind of enamel coating process requirements.