The manway is a ideal way to check or clean tank inside, also can beused as feed port.There are round,rectangular,lliptical, and pressure type,1-5 bar pressure is common use,customized is available.When need repair the tank,first to unscrew the handwheel(use to fixed manhole cover and supply the force to axial seal),then open the manhole cover by the handle which fixed in the manhole cover (manhole cover is jointed together by hinge and frame,to ensure accuately closure when the manhole cover close,and the hinge can let the opened manhole cover stop above 30 degree angle of upright position),thus the serviceman can check the storage tank,when the manhole cover closed ,both of the seal of manhole cover and the tank can ensure complete sealing ,So we can avoid leakage of the tank.The man hole is mainly used for pressure vessel in the fields of food,beverage,chemical, etc.