The difference between the drain valve and control valve

One: the definition of the drain valve, drain valve is used for steam pipe network and equipment, can automatically discharge condensate, air and other gases not condensation, and resistance steam leakage of the valve gate. Steam drain valve is installed between the steam heating equipment and water back into the manifold. When driving, barrel at the bottom, the valve fully open door. After the water into the drain valve flow to the bottom, with the valve body, completely submerged barrel, and then, the condensate by a fully open valve door to the back to the manifold. The steam from the bottom of the barrel into the drain valve, occupy the top of the barrel body, create buoyancy. Barrel rises slowly, moves in the direction of the valve seat lever, until completely close the valve gate. Air and carbon dioxide gas vent holes through the barrel, gathered at the top of the drain valve. From the vent discharge of steam, is due to the drain valve of the cooling and condensation. When in the condensate began full barrel barrel to leverage to create a pull. As the condensation water level rising, the force of increasing, until can overcome the pressure difference, door open the valve. Valve gate began to open, the differential pressure effect on the valve disc will be reduced. Barrel will fell rapidly, make the valve door open. Accumulate in the drain valve at the top of the no non-condensable gas discharge first, and then discharge frozen water. Drive the dirt out together when water flowed from barrel drain valve. Condensate emissions at the same time, steam to start into the drain valve, and a new cycle begins. 2: control valve, control valve is a kind of using water from the lip type valve body, do not need to add oil lubrication, in case of the inside of the main valve parts, please follow the instructions below to remove. ( Note: in general consumption damage product for the diaphragm valve body and ring, other internal components damage little) 1. Main valve before and after the end of the first gate door closed. 2. The piping on the main valve cover joint screw loosening, internal pressure release valve. 3. All the screws removed, including controlling necessary pipeline brass nut. 4. The valve cover and spring. 5. To get off axis core, diaphragm, piston, do not damage the diaphragm. 6. Remove the above things, diaphragm and examine whether the protection ring damage; If no damage do not again points to its internal parts. 7. If found that the diaphragm or ring was damaged, please loose the nut on the axis core, get to decompose the diaphragm or circle, comes out to replace the new diaphragm or ring. 8. To examine in detail the main valve inside there is no damage to the valve seat, shaft core, etc, if you have any other debris inside the main valve to clear it. 9. Is in reverse order will replace the parts after combination installed main valve, no jam phenomenon should be the valve gate. 10. Please refer to installation considerations to use operation. The distinction is obvious, one is the output is the input.