1. Select the appropriate connection method according to the caliber and the specific conditions of the pipeline
A. Welding: According to the site progress, enter the installation at an appropriate time. Fix the bracket in advance, draw a sketch according to the actual size, and prefabricate the pipeline, to minimize the number of pipe fittings on the pipeline and weld dead joints. The pipe should be straightened in advance, and the opening should be closed when the installation is interrupted. If the design requires casing to be added, the casing should be added during the installation process. According to the design and equipment requirements, the interface should be reserved and plugged in to prepare for the test of the next process. pressure work.
B. Threaded connection: Pipe threads are processed by threading machines. The 1/2″-3/4″ pipe can be threaded manually. After the thread is threaded, the nozzle should be cleaned to keep the nozzle smooth. Broken threads and missing threads should not exceed 10% of the total number of threads. The connection should be firm, there should be no exposed hemp at the root, the exposed thread at the root should not exceed 2-3 threads, and the exposed part of the thread should be well anti-corrosion.
C. Flange connection: Flange connection is required for the joints between pipes and valves. Flanges can be divided into flat welding flanges, butt welding flanges, etc. The flanges are selected from finished products. The flange is perpendicular to the center line of the pipe, and the nozzle must not protrude from the flange sealing surface. The bolts fastening the flange should be brushed with lubricating oil before use and 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 nut should be on the same side, and the flange gasket should not protrude into the pipe, There shall be no sloping pads and more than two pads in the middle of the flange.
2. Anti-corrosion: two coats of silver powder on the outside of the galvanized steel pipe, and two coats of asphalt on the outside of the galvanized steel pipe.
3. Before laying and installing the pipeline, the internal dirt should be cleaned up to prevent welding slag and other garbage from falling into the pipeline, and the installed pipeline must be bandaged and sealed.
4. After the construction is completed, the whole system should be tested for hydrostatic pressure. The pressure of the domestic water supply part is: 0.6mpa and the pressure drop within five minutes is not greater than 20kpa, which is qualified.