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0 <br /> Repair procedures Cutting repair couplings <br /> (cont.) On 2-inch couplings the center holes have been located near the middle of the <br /> coupling.Cut exactly between these two holes.The resulting half-couplings are <br /> 7 inches long.Two cuts are necessary when making 3-and 4-inch half-couplings. <br /> The resulting half-couplings are 51h inches long. <br /> D D <br /> 0 0 0 <br /> 0 0 0 0 <br /> 0 0 0 0 <br /> nch <br /> Fig. Cut full-lengthso Cuttomakengs <br /> 9 9half-couplings <br /> that all bolt holes on half-couplings Cut to make 3- <br /> are equidistant from the ends. and 4-inch <br /> half-couplings <br /> 10 Primary system Recommended practices <br /> testing Plan tests carefully and carry them out with all due precautions.Pressurizing equipment <br /> should be suited to the size of the system and the pressure required and should be <br /> operated by qualified and experienced personnel only. <br /> r------------------------------ <br /> I The following recommendations are offered only as a guide.Ameron assumes no 1 <br /> responsibility or liability for the consequences of any testing practices. 1 <br /> L----------------------------- <br /> • Pressure sources should be capable of approaching test pressure gradually. <br /> • Use gauges with a full-scale reading of no more than twice the test pressure:Do <br /> not use a 100 psi gauge for a 10 psi test.Use reliable gauges calibrated against a <br /> dead weight tester and zeroed for atmospheric pressure. <br /> • Isolate tanks from the piping when pressure testing. <br /> • The recommended hydrostatic pressure is 150%of expected operating pressure <br /> and should be maintained at least 10 minutes. <br /> • Do not exceed 150%of system rating.Check the pressure rating of all the <br /> components ofthe system—notjust the pipe—because hoses and flexible <br /> connectors are almost always rated lowerthan the pipe. <br /> • Do not adjust fittings while system is under pressure.Ifthreaded adapters or <br /> bushings leak,release the pressure before attempting to tighten. <br /> • Temperature changes can affect the pressure in the test line.Substantial pressure <br /> increases may occur in closed systems exposed to the sun.Conversely,overnight <br /> decreases in pressure due to cooling from afternoon to early morning are normal <br /> and do not necessarily indicate a leak. <br /> • Aftertesting,maintain 5 to 10 psi(35 to 70 kPa)in the system during subsequent <br /> construction so that damage caused by stakes,excavation equipment,etc.can be <br /> detected and corrected before pavement is installed or product is pumped. <br /> r------------------------------ <br /> Ameron recommends hydrostatic testing of primary systems as the effects of <br /> 1 sudden pressure loss when testing with liquids are far less severe than with gases.If i <br /> pneumatic testing is necessary,restrain the system adequately to prevent damage <br /> or injury in case of rapid pressure loss.Pneumatic testing can be extremely <br /> dangerous. i <br /> L-----------------------------J <br /> 15 <br />