Ball valve classification 1), commonly used ball valve according to their working principle is divided into floating ball valve, fixed ball valve, lifting rod valve and so on. 2), the ball valve according to the channel position can be divided into straight-through, three-way and right angle. The latter two ball valves are used to distribute the medium and change the flow of the medium. Ball valve construction and installation points 1), installation location, height, direction of import and export must meet the design requirements, the connection should be solid and tight. 2), installed in the insulation pipe on all types of manual valves, the handle shall not be down. 3), the appearance of the valve must be installed before the inspection, the valve nameplate should be consistent with the current national standard "General Valve Flags" GB 12220 requirements. For the working pressure is greater than 1.0 MPa and the main pipe to play the role of cut-off valve, the installation should be carried out before the intensity and tightness test, qualified after the standard use. Strength test, the test pressure of 1.5 times the nominal pressure, the duration of not less than 5min, valve housing, packing should be no leakage as qualified. Tightness test, the test pressure is 1.1 times the nominal pressure; test pressure in the test duration should be consistent with GB 50243 standard requirements, no leakage valve plate sealing as qualified. 4), valve flange and pipe flange according to the pipeline design requirements installed gaskets. 5), with the ball valve drive, according to the instructions of the product installation instructions. Standard 1), product standard "common valve flange and butt welded steel ball valve" GB / T12237-89 "iron and copper ball valve" GB / T "General requirements for steel valves" GB / T 12224 -2005 "drinking water distribution equipment and protective materials safety evaluation criteria" GB / T 2), engineering standards "building water supply and drainage engineering and construction quality acceptance norms" GB "ventilation and air conditioning Acceptance of construction quality standards "GB 50243-20 Use 1, before installing the valve to be sure to confirm the internal pipe and body passage has been cleaned. 2, the operation of the ball valve driven by the actuator driven valve stem rotation complete opening and closing, forward rotation 1/4 turn (90 °), the ball valve is closed. The ball valve opens when rotated 1/4 turn (90 °) in the reverse direction. 3, when the implementing agency direction arrow parallel with the pipeline, the valve is open; the arrow and the pipeline perpendicular to the direction, the valve is closed. Reduce the amount of maintenance methods: To make the hard seal ball valve has a longer service life and maintenance-free period, the valve must be in normal conditions to maintain a harmonious temperature / pressure ratio, and in line with the valve body material corrosion data.