A. According to the diameter and specific conditions of the pipeline, select the appropriate connection method
1. Welding: enter the installation at the appropriate time according to the progress of the site. Fix the bracket in advance, draw a sketch according to the actual size, prefabricate the pipeline, reduce the number of fittings on the pipeline and weld dead ends as much as possible. The pipe is straightened in advance, and the opening should be closed when the installation is interrupted. If the design requires a casing, the casing should be added during the installation process. According to the requirements of the design and equipment, reserve the interface, plug it, and prepare for the test of the next process. pressure work.
2. Threaded connection: The processing of the pipe thread is completed by a threading machine. 1/2″-3/4″ pipe can be artificially threaded. After the thread is finished, the nozzle should be cleaned and the nozzle should be kept smooth. The broken thread and the missing thread should not exceed 10% of the total number of threads. The connection should be firm, there is no exposed oil hemp phenomenon at the root, the exposed thread at the root should not be more than 2-3 buckles, and the exposed part of the thread should be well protected from corrosion.
3. Flange connection: Steel flange connection is required for the connection between the pipeline and valve. Flanges can be divided into flat welding flanges, butt welding flanges, etc. The flanges are finished products. The centerline of the flange and the pipe shall be vertical, and the nozzle shall not protrude from the sealing surface of the flange. The bolts that fasten the flange should be brushed with lubricating oil before use. It should be symmetrically crossed and tightened 2-3 times. The exposed length of the screw should not exceed 1/2 of the diameter of the screw. The nuts should be on the same side, and the flange gasket should not protrude into the pipe. , There shall be no inclined gasket and more than two gaskets in the middle of the flange.
B. Anti-corrosion: Two coats of silver powder are installed on the outside of the
galvanized steel pipe, and two coats of asphalt are installed on the
galvanized steel pipe in the dark.
C. Before the installation of the pipeline, the internal dirt should be cleaned up, and the garbage such as welding slag should be strictly prevented from falling into the pipeline. The installed pipeline must be wrapped and sealed.
D. After the construction is completed, the entire system should be subjected to a hydrostatic pressure test. The pressure of the domestic water supply is: 0.6mpa and the pressure drop within five minutes is not more than 20kpa, which is qualified.
