Because large-diameter pipelines are buried in the ground on most occasions, a cement pit should be made before the installation of large-diameter sensors. Figure 6-19 shows a common installation form in the water supply and drainage system.
The concrete pit should have enough space for movement. The side walls are buried with steel pipes for laying cables, and there is a cover plate on the top to prevent rain, and there should be a drain pipe below to prevent the sensor from being immersed by water in the pit.
In order to facilitate the disassembly and assembly, the sensor should be placed on the foot, and a flexible telescopic tube is installed on the downstream side. Figure 6-20 is an example of the installation of an electromagnetic flowmeter in an underground cement pipe sewage discharge system.
1-Inlet pipe；
2-overflow；
3-Inlet boss;
4-Clear hole；
5-Sensor;
6-Removable parts；
7-Wall seal；
8-Outlet pipe；
9-Drain valve