Supply Of Cables In The Pipe
The installation of open and hidden electrical lines in steel tubes requires the cost of scarce materials and crafts. They are therefore used to protect wires against mechanical damage, as well as to protect the insulation and the wires themselves against the devastation of edible vapours and gases, the ingress of the moisture, dust and explosive mixtures from the environment.
Connections and adhesion of tubes to boxes, machines and electrical receivers shall be carried out without special sealing (when used to protect wires against mechanical damage), sealed (to protect pipes against dust, moisture, eating vapours and gases) and explosives in order to prevent the possibility of entering pipes, machines and electrical receivers of explosive mixtures.
The steel pipes used for electrical connections are divided into three groups: water-gas-conducting, light and thin-line electrical welds.
Before the installation, the inner surface of the tubes shall be cleaned from the occalines and grats and shall paint the inner and outer surfaces of the asphalt patch. Tubes in the concrete are not painted outside for better adhesion with concrete. The zincope pipes are laid without paint. In mounting the normalised values of the angles and radius of the bend of the tubes, depending on pipe diameterthe quantities and sections of their wires. Waterconducting pipes are used only in explosive installations; lungs are used in reasonable (in terms of metal economy) cases when they are open in dry and wet rooms; and under cover in dry and wet rooms, at worms, in tidal floors, foundations and other construction elements, with sealing in crusts. Tonco-small pipes shall be used when open in dry and wet rooms, without sealing the junction points and entering the boxes.
Electrical installation organizations use the industrial method of installation of steel pipes. The preparation, treatment, cleaning, painting, fitting and packing shall be performed in the MEA.
