Coal water slurry is a kind of coal- based liquid fuel. Generally speaking ,it is a mixture which composed of 60% coal powder ,35% water and small Cl ion , FeSO4,NH3 etc .CWS is solid and liquid mixture ,which contains high hardness solid particle and corrosive material .Tank bottom angle valve works as on and off valve ,so the system have a high requirement of tank bottom angle valve in anti-abrasive, anti-flushing and anti-corrosive performance . Tank bottom angle valve usually is installed on the bottom of the tank to discharge the fluid .
 
FREE-valve’s tank bottom angle valves are divided into disc opening into the valve and disc opening into the tank . Sometimes ,they are also called open-down type and open-up type . The difference between the two types of tank bottom angle valve is the following : Opening into tank type is a special kind of globe valve . When the valve opened, valve stem will move upward and disc will go the inner of tank .However ,for the tank bottom angle valve (opening into the valve ) type ,when the valve disc rising ,valve will be opened and valve disc will be hidden into the valve body .
As opening into the tank type ,the fluid flowing besides the inlet and outlet of the valve rate is quite high . So abrasiveness will be occurred on the valve disc at some extent .For this structure ,the required axis distance will be little ,so it can save the space cost .For opening into the valve type ,the valve disc will hidden into valve body  ,it can protect the valve disc from being flushing .The new generation valve with short axial distance is designed to reduce the material cost .