Mansfield Genuine 630-0030 Flush Valve Seal The Red Seal Is The Only Seal To Fit The Tower Flush Valve. Click The Picture to see an instalation video for the mansfield 006300030 210/211 Flush Valve Seal UPC: 046587000088. This seal is flat. After being used it may develop a ridge or cone shape. It is the most common cause of the toilet leaking and being hard to flush. When installing it please watch the installation video by clicking the image. The package says it's for 210 and 211 it is referring to the flush valve model number not the tank number.