Due to long-term exposure to ultraviolet radiation, polypropylene PP ducts are prone to aging and degradation. When installed outdoors or in direct sunlight, it must be wrapped with a dark protective layer. Except for mechanical connection with metal pipes or water users, such as threaded inserts, the rest should be connected by hot melt, so that the PP duct is integrated and there is no leakage point. The linear expansion coefficient of polypropylene air pipe is relatively large, and technical measures must be taken to prevent the expansion and deformation of the pipe when it is installed or buried in the dark. When installing PP plastic air ducts, the influence of ambient temperature on the installation quality should be considered. Generally, when the temperature is higher than 40℃ or lower than 0℃, it is not suitable for construction and installation.

When the polypropylene PP air pipe is laid overhead, the pipe should be supported by the pipe support. The pipe support can be made of angle steel, split steel pipe and other materials so that the reinforced polypropylene can expand and contract freely on the pipe support. When the PP plastic duct needs to be concealed, it is recommended to lay it in a trench. Generally speaking, pipes are connected by welding. If it is necessary to bury for special reasons, it should be directly buried in the form of a casing pipe to avoid mixing hard debris in the backfill and reporting an error pipe. When the PP air pipe is connected by flange, it should be strictly aligned, the allowable axial deviation is not more than 2mm, and the method of forcibly tightening the bolts should not be used for adjustment.

When the polypropylene PP duct is exposed or buried in the dark, the support and hanger must be installed as required. During the welding process, the polypropylene PP air pipe cannot produce flanges or unevenness. Visually, the front and rear pipes cannot be in the same plane during the welding process. The strength of the hot-melt joint of the laboratory ventilation pipe is higher than that of the pipe body, and the joint will not be broken due to soil movement or load. Polypropylene ducts are less rigid and impact-resistant than metal ducts and are easily damaged during storage, transportation and construction. When the pipeline is installed or buried in the dark, technical measures must be taken to prevent expansion and deformation.

The ventilation pipe in our laboratory has a strong water supply capacity, smooth inner wall, low water resistance, not easy to block, and drainage capacity is higher than that of cast iron pipes of the same diameter. The engineering cost of polypropylene PP air pipe is lower than that of metal pipe, and the economic benefits are obvious. The bending strength of the laboratory ventilation pipe is above 45MPa, which is convenient for transportation, loading and unloading, storage and construction. PP air duct inspection wells cannot be used to irrigate cushions and foundations with water. The geometric size and height of the foundation should be guaranteed, and the construction should meet the design requirements. Bricks can only be laid after the concrete reaches a certain strength.