Universal mounting device for branch pipe flange on pressure vessel

The invention discloses a universal mounting device for a branch pipe flange on a pressure vessel, which comprises a supporting base and a universal turntable, a vertically mounted supporting vertical seat is detachably arranged on the supporting base on the outer side of the universal turntable, and at least one branch pipe horizontal conveying supporting device for fixing the branch pipe flange is movably mounted on the supporting vertical seat. Mounting height scales are arranged on the supporting vertical seat and positioned on the side part of the branch pipe horizontal conveying and supporting device; the pressure vessel is placed on the universal rotating disc, the branch pipe flange is fixed to the branch pipe horizontal conveying supporting device, through cooperation with installation height scales, the branch pipe flange is adjusted to the installation height of the branch pipe flange, the height is kept fixed, and the branch pipe flange is conveyed into an installation reserved opening in the pres