If there is enough space in the pipeline well (maintenance space is required) and there must be unified protection and management facilities at the entrance of the pipeline well, household heat meters can be installed in the pipeline well; However, at present, most pipeline wells (generally in the wall between the landing) are designed with the same width as the stairwell, so the space is not very large. Only the pipeline and the locking valve can be installed, and the opening and closing of the locking valve can be operated from the entrance of the pipeline well. However, the installation of heat meter is very tight, which is not suitable for disassembly and maintenance in the future. Therefore, heat meters are generally installed indoors. After the pipeline enters the house, you can choose a straight pipe section not less than half a meter for installation, which is installed on the water supply pipeline, and valves can be installed on the back of the instrument and the return pipeline. The main functions of these two valves are: there is no need to discharge a lot of water from the indoor system when repairing or replacing the heat meter, and another function is that once the user finds that the water leakage in his home is serious, he can quickly close the valve in an emergency to prevent the disaster or loss caused by indoor water leakage!