Water heater closed open type which is good?
The control mode of the closed electric water heater belongs to the back system, namely, the water inlet and the water outlet of the electric water heater are controlled by a valve installed on the water outlet pipe. Since the water inlet of this water heater must be in normally open condition, when the water is filled and the valve is closed, the pressure in the bucket will be the same as that of the tap water. In fact, the inner barrel of a closed electric water heater is a pressure vessel, so it must be agreed on its rated working pressure and pressure capacity so as to ensure its normal and safe operation. This national standard (GB4706.121995): closed type electric water heater minimum rated working pressure is 0.6MPa, voltage value provides two times the rated working pressure of the. At present, the market closed type electric water heater, rated work pressure is mostly 0.6MPa, and must pass the 1.2MPa pressure test before leaving the factory. In this way, the safety of water heater pressure is guaranteed.
First, about the open typeThe utility model relates to a control mode of an outlet open type electric water heater, which belongs to a front system, namely, the water inlet and the water outlet of the electric water heater are controlled by a valve installed on the water inlet pipe. Since the outlet of the water heater is opened to the atmosphere, the water heater bucket only accepts the static pressure of the internal water. It can be said that there is no pressure requirement. When heated with water, the water expands when heated and the water drips out of the water outlet. This is normal.
There are two common electric water heaters: one is an open outlet electric water heater, and the other is an enclosed electric water heater. These two kinds of electric water heater main body structure is exactly the same, but different in control of water inlet and outlet, and the different of the two electric water heater have a great difference in the status and the function, working pressure on. The requirements for safety performance are also different.
How can the enclosed electric water heater work under the rated working pressure? This task is accomplished by a safety valve mounted on the inlet pipe. The relief valve is actually a combination of one check valve and one relief valve. Check valve is also called non-return valve, it makes water can only enter, can not go out. Thus, when the pressure in the bucket is greater than the tap water pressure, the hot water can be prevented from flowing into the cold water pipeline, and the hot water can be prevented from losing water when the tap water is accidentally cut off. At the same time, the one-way valve also makes the inner barrel of the water heater a closed system. When the heater is heated with water, the pressure in the barrel increases. We set pressure relief valve pressure is slightly higher than the rated work pressure, generally set at around 0.7MPa. So, once the barrel pressure exceeds the set pressure, there will be some water safety valve overflows out of the barrel of pressure drop below the pressure setting. The overflow of the safety valve has leakage of water drop, indicating that the relief valve is working normally.
