Steam drain valve test method

1 the scope of this standard specifies the steam drain valve test method and test apparatus. This standard applies to mechanical and thermal static and dynamic type steam drain valve ( Hereinafter referred to as the drain valve) Factory inspection and type testing. Test unit 2. 1 action test, the minimum working pressure experiment, the highest working back pressure and maximum working pressure test of test device. 2. 2 steam leak rate test, the temperature of drainage, water displacement test, the test and the temperature of drainage, the highest test with the test device. 2. The general requirements of 3 test rig a) High pressure tank capacity not less than 2 m3; b） Back pressure tank capacity not less than 1 m3; c） Measuring tank volume is not less than 0. 2m3； d） Temperature, pressure, weight with the precision of the measuring instrument is not lower than 0. Level 5, timing instrument accuracy is not lower than & plusmn; 0. 2%, the resolution is not greater than zero. 1 s; e) All hot line in the device and equipment should be insulated. 3 test method 3. 1) shell test a Test medium: water, kerosene or other liquid viscosity is not more than water; b） Test pressure: nominal pressure of 1. 5 times; c） Medium temperature: room temperature; d） To assemble, import and export side pressure test within the drain valve is closed, in table 1 within the stipulated time, shell can not have leakage, internal parts can not have residual deformation. Nominal diameter/DN test duration/s≤ 50 > > 60, 1565 ~ 150 using steam, air and other gas testing, safety measures, and approved by the relevant departments. 3. 2 action test to the drain valve factory steam, drain valve shall be closed, and then introduce a certain rate of hot water, drain valve should be open, Time needed for opening vary with drain valve type) , the condensate drain valve shall be closed again after discharge. At least 3 full circle, the test is completed. For seal below the water seal airtight float and design features of mechanical type air and water drain valve is available. For disc the drain valve at the inlet is in a state of full steam, the valve slice the beat frequency is not more than 3 times/min. For larger supercooling degree of the drain valve of the close degree of supercooling design no bigger than a given value. 3. According to the 3 3 minimum working pressure test. 2 provisions action experiment was carried out, at the same time, gradually reduce the test pressure, until the minimum working pressure. In the process of the whole test drain valve should be able to correct opening and closing. 3. According to the 3 4 highest working pressure test. 2 the provisions of the motion experiment was carried out, at the same time, increased testing pressure, until the maximum working pressure. In the process of the whole test drain valve should be able to correct opening and closing. 3. 5 the highest work back pressure test under the maximum working pressure press 3. 2 the provisions of the motion experiment was carried out, at the same time, increased drain valve outlet pressure, until the drain valve can not correctly. Drain valve can correct opening and closing the highest outlet pressure is the highest work back pressure. 3. 6 air discharge capacity test will not be greater than zero. 3 mpa air drain valve of our factory, drain valve should be able to discharge the air, in 5 min time allow the closing of the drain valve is short, but the closing time shall not be greater than 1 min. 3. Temperature of drainage, 7 test to the drain valve is closed when the steam of our factory to make it, and then introduced the condensate saturation temperature. If the drain valve can't immediately open, waiting for drain valve slowly cooling, until the drain valve automatically open, open the inlet water temperature is to open the valve temperature. Then gradually rise in temperature of the frozen water, until the drain valve automatically shut down, close the import of the condensate temperature is close the valve. 3. 8 amount of steam leakage test in a given job under pressure to the drain valve is introduced into rate for ( 6± 3) % of the hot water, for saturated steam at the same time, access to the drain valve of the condensate into regulation capacity measuring tank, using heat balance method to calculate the steam leakage quantity. The amount of steam leakage test method according to the provisions of the appendix A. 3. 9 water capacity test hot water displacement is under a certain pressure difference and the condensate temperature measured discharge hot water weight per unit time. Hot water displacement under different pressure difference should be measured under the same degree of supercooling. Usually hot water capacity test can make the drain valve outlet to the atmosphere. Hot water capacity test method according to the provisions of the appendix B. Note: the above 3. 3 to 3. 8 do not apply to the impulse type and pore plate drain valve.