The following for the boiler system of several types of valves: the main steam safety valve, solenoid vent valve PCV, boiler circulating pipe control valve, main water bypass control valve, Reheater water spray control valve, steam turbine high-pressure valve, to do a simple introduction.
1. Main Steam Safety valve This type of valve in the reheat outlet caliber is smaller, about 150mm (6 inches), pressure of 7 MPa, now in the three types of valve development project I want to use the main steam engine, used to the superheater exit, Then its pressure will reach 27.6 MPa, the main steam flow than the reheater flow is large, nearly 3 times times, so its caliber will also become larger, so these are the development of this type of valve difficulties. This kind of valve needs us in the spring, stem, disc and seat of the seal on the issue, the choice of spring materials are also very fastidious.
For the tower boiler is a hundred percent bypass, in the reheat outlet, also need to use the safety valve, this kind of safety valve is a brand with pneumatic auxiliary device similar to the electric release valve such safety valve, such safety valve caliber is also very big, probably 300mm, also may also be we will study the direction.
2, electromagnetic relief valve, that is, PVC valve This type of valve has a different place than the safety valve just introduced, it has a pressure switch to control through the pressure, there is a switch, b switch or more switches to achieve a forced open purpose.
This valve is more prone to problems in operation, so it often links to a closed valve, the shutoff valve type may be a ball valve may also be a valve, often this valve will have a pilot valve, first open the small pilot valve later through the auxiliary steam to promote the whole valve open.
3. Boiler Circulating Pipe Control valve For the super (super) critical boiler after more than 150 hours of downtime, will be taken to the pipeline flushing, in the process of flushing is the first open flushing, and then closed-type flushing, when the water pump separator exports of iron content is less than 100ug/l when we do a cycle of flushing. Because a part of the water will always be discharged, in order to control the discharge of water, reduce losses, so we will increase the circulation of the pipe control valve.
This valve normally starts under the 30%-25% load.
4, main water bypass control valve
This kind of valve is similar to the circulating pipe regulating valve type just mentioned, here is not tiring.
5, Reheater water Spray Control valve
Reheater water Spray Control valve looks similar to the previous two types of valves, first, this type of valve is not often used, and second, it's more water spray, but it is used as an accident spray water.
6, Steam turbine high-pressure supply control valve Steam turbine valve should be a valve set, it is often caused by the steam turbine gas seal in the high load state inside and out without leakage, three valves together, all the way from the high-pressure pump, never to leak, will not destroy its vacuum environment, not to the external leakage, can be connected to the line from the low pressure side, Its purpose is to reduce the loss of steam work.