减压阀英文说明书.doc

The Piston-type Steam pressure reducing valve Instruction manual Configurations: 1Lower cover7Piston ring13Diaphragm 2Body8Cylinder 14Adjusting spring3Main valve spring9Secondary valve spring15Valve cap 4Main valve seat 10Upper bonnet16Adjusting screw5Main valve11Secondary valve17Top cap 6Piston 12Secondary valve seatMain performance and uses: Y43H is principally used in steam pipe, it can reduce the inlet pressure to a certain outlet pressure you need by adjusting the spring, when the flow and the pressure of the inlet varies, the outlet pressure can also remain within a certain range by the strength of the medium itself, but the differential pressure of the inlet and outlet must be equal or greater than 0.2MPa. Technical parameter:DN(LB)Pressure test (MPa)Pressure-adjust range (MPa)ApplicableTemperatureShell test Seat test Import pressureexport pressureexport deviation3007.55.52.50.51.60.7250Working principal: When the pressure reducing valve leaves the factory, the adjusting spring is in uncompressed state, the main valve disc and secondary valve disc is in close position. When you want to use it, you can turn the adjusting screw clockwise; this can compress the adjusting spring, move the diaphragm down and then open the secondary valve disc, the medium also enters above the main valve seat through “a” hole to “b” hole, make the main valve disc open and then enters under the diaphragm through “c” hole. But when the downstream pressure is exceed the set pressure, the medium moves the diaphragm up and compresses adjusting spring, and then the secondary valve disc closes slowly, because the flow reduces, the downstream pressure get a new balance, on the other hand, when the downstream pressure is less than the set pressure, the gap between the main valve disc and the main valve seat increases and then the flow increases too and then make the downstream pressure get a new balance. Installation and maintenance:1. Clean the valve and the pipe line and remove the dirt before installation, at the same time the valve must be installed in horizontal direction, bracket is needed when the valve deadweight is heavy or vibration exists at the site.2. While installing, make sure the flow direction and the direction marked on valve body is consistent, and a bypass pipe is usually required. When the valve size and the pipe size differ, reducer should be adopted. The installing site should have sufficient space for a convenient usage and maintenance. 3. When the valve is put into use, the bypass globe valve must be opened, remove the condensate and the water vapor mixture in order to avoid the water hammer occurred by opening the valve. If there is no unusual phenomenon appears, you can turn the adjusting screw clockwise till getting the outlet pressure we need, then lock the nut and cover the top cap. 4. A filter must be installed before the pressure reducing valve which prevents the impurities from getting into the valve. 5. There must be a straight pipe at least 600mm and 1000mm seperately before and after the pressure reducing valve.6. A water-vapor separator and a steam trap should be installed before the pressure reducing valve, atfter which a steam trap should also be installed.7. Pressure reducing valve should be kept in a dry room, both of which should be blocked with blind plates. Do not keep in piles.8. If the pressure reducing valve will be kept for a long time, we must check it regularly, clean up the dirt and spread some rust-proof oil on the movement part and the machined surface.9. If the outlet pressure is higher than the inlet pressure, we must reset the pressure reducing valve as follows: Shut off the upstream isolating valve; Relief the downstream pressure; Turn the adjusting screw counterclockwise, make it in a free poisition. Open the upstream isolating valve slowly till full open. Turn the adjusting screw clockwise, the outlet pressure rises slowly to the set value, then lock the adjusting screw. If you adjust the press