Welding technology of air energy heat pump water heater tank

The air energy heat pump water tank is mainly divided into pressure-bearing type and non-pressure-bearing type. The pressurized water tank mainly faces the household tap water supply system and uses the pressure of tap water to provide power supply. The inner tank is a closed container. When the user closes the water valve, the water tank needs to withstand the pressure of the water pipe network, and the water heater is subjected to higher pressure when heated. The non-pressure-bearing type is mainly used in places where the required water volume is large, the tank liner is connected to the atmosphere, the liner is not a closed container, and the water supply requires additional power such as a water pump.Therefore, the pressure tank has higher requirements on the quality of the liner. This paper mainly discusses the pressure tank. Among them, there are two kinds of pressurized water tanks: stainless steel pressurized water tank and enamel pressurized water tank. At present, most of the products in the heat pump water heater market are stainless steel water tanks. The material of the stainless steel pressurized water tank is similar to that of the electric water heater and the pressure-bearing solar water heater. Stainless steel is mainly made of austenitic stainless steel (main grades SUS304, SUS316, SUS304L and SUS316L) and ferritic stainless steel (main grade SUS444); low carbon steel grade is mainly Q235A. The welding of stainless steel water tank is mostly welded by argon arc welding. The low carbon steel water tank is mostly welded by CO2 gas shielded welding, and the groove form is mostly V-shaped groove.