According to the different types, diameters and construction methods of pipes, the construction site shall be leveled as required before the pipes are transported to the construction site.
When placing pipes beside the trench, factors such as not blocking the road, not affecting the safety of the trench, and convenient pipe laying shall be considered. The socket direction of socket type pipes shall be consistent with the forward direction of pipe laying as far as possible. In the slope area with large slope, the socket shall be upward during pipe compensation, and the socket ends shall be staggered to facilitate pipe installation. For construction in a narrow section of the site, the pipes transported in shall be immediately lowered into the trench and shall not be placed at the edge of the trench.
The lifting, transportation and moving of pipes, pipe fittings and equipment shall be firm and handled with care, especially for cement pressure pipes. During long-distance transportation, the socket Switzerland Department shall wrap it with straw rope and secure it securely.
Before pipes, pipe fittings and valves are lowered into the trench, special personnel shall be arranged for quality inspection.
For cast iron pipes, the pipe fittings shall be checked for longitudinal and transverse cracks, severe delamination, pipe wall gouging, sand inclusion and perforation. Elephants. Those with these defects shall not be used.
The appearance inspection of pipes and pipe fittings mainly depends on visual inspection. Liu Yu checks whether the ends of metal pipes and pipe fittings are cracked with the sound of hammering. The cracked part has a hoarse knocking sound.
The sundries in pipes and fittings shall be removed. For metal pipes and pipe fittings, except the socket and spigot working faces, those that have not been subject to anti-corrosion treatment shall be repaired.
Rust shall be removed from the end of the ground cover for on-site assembly welding. Before welding, the quilt shall be processed according to the drawing. After welding, the anti-corrosion coating shall be applied. The asphalt layer deposited on the working face of the socket and spigot of the cast iron pipe that affects the tightness of the interface shall be scraped off or burned, melted and blown off with gas welding. The size of socket and spigot cannot guarantee the normal joint of the real material of the interface
Gap. It shall be used after correction.
If the cement pressure pipe has defects such as falling off of the protective layer, hollowing, corner dropping, exposed reinforcement or exposed gravel, it shall be repaired and used after being qualified. The working surface of socket and spigot shall be free of concave convex defects. Since the gap between the boss at the socket and the socket is very small, the height of the boss at the socket exceeds the standard size by ± 2mm, which will cause difficulties in installation.
The valves and other equipment have been subject to hydrostatic inspection one by one before leaving the factory. The appearance inspection shall be carried out during assembly. It is required that the components are complete, the valve body is intact, the sealing filler is appropriate, and the mud and sand debris in the valve body are removed. Open and close the valve to check whether it is fully opened and tightly closed, and record the opening and closing speed and rotation direction. For the valve to be used again, the pressure test shall be conducted again, and the valve shall be installed after it is qualified.
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