How to install galvanized steel pipes

First, choose the appropriate connection method according to the caliber and specific conditions of the steel pipes.
1. Welding: Install at the appropriate time according to the progress of the site. Fix the bracket in advance, draw a sketch according to the actual size, and prefabricate the steel pipes to minimize the installation of steel pipe fittings and welded joints. Straighten the steel pipe in advance, and close the open end when the installation is interrupted. If the design requires the addition of a casing, add the casing during the installation process. According to the requirements of the design and equipment, reserve the interface, plug it in, and prepare for the pressure test of the next step.
2. Threaded connection: The processing of steel pipe threads is done by a threading machine. 1/2″-3/4″ steel pipes can be manually threaded. After the thread is set, the steel pipe mouth should be cleaned and kept smooth. The broken and missing threads should not exceed 10% of the total number of threads. The connection should be firm, with no exposed oil hemp at the root, and the exposed threads at the root should not be more than 2-3 threads, and the exposed part of the thread should be well resistant to corrosion.
3. Flange connection: A flange connection is required for the connection between steel pipes and valves. Flanges can be divided into flat welding flanges, butt welding flanges, etc., and finished products are used for flanges. The center line of the flange and the steel pipe is perpendicular, and the mouth of the steel pipe shall not protrude from the flange sealing surface. The bolts for tightening the flange should be brushed with lubricating oil before use and should be symmetrically cross-tightened 2-3 times. The exposed length of the screw should not exceed 1/2 of the screw diameter. The nuts should be on the same side. The flange gasket should not protrude into the steel pipe. There should be no inclined gaskets or more than two gaskets in the middle of the flange.

Second, anti-corrosion: The exposed galvanized steel pipe should be brushed with silver powder twice, and the concealed galvanized steel pipe should be brushed with asphalt twice.

Third, the internal dirt should be cleaned before the steel pipeline is laid and installed, and the garbage such as welding slag should be strictly prevented from falling into the steel pipe. The installed steel pipe should be wrapped and sealed.

Fourth, after the construction is completed, the entire system should be subjected to a hydrostatic pressure test. The pressure of the domestic water supply part is: 0.6mpa, and the pressure drop within five minutes is not more than 20kpa, which is qualified.