the flared extension 112 fig2 illustrates a modification in which the flared extension 212 is not skewed but the central axis of the float assembly is nevertheless offset from the central axis of the flange of the valve base by virtue of a skewed lower extension 214 thus in the case of fig2 the extension comprises a lower skewed portion and an upper flared portion the structure of the float is the same in the case of fig2 as in fig1 a fig3 illustrates a further modification of the flush valve structure shown in fig1 a as shown in fig3 the extension of the valve base comprises a lower portion in the form of an s shaped tube 770 and a flared upper portion 212 the s shaped tube allows the flush valve to be positioned near one of the side walls of the toilet tank fig4 illustrates a further modification of the flush valve structure in this case a valve base 514 provided with a seal 516 is fitted in a circular recess in the floor of the tank and the circular recess is surrounded by an annular plateau 518 the seat 530 is provided at the top of the annular plateau which has a frusto conical interior surface tapering downward towards the entry to the outflow tube 526 in the case of fig4 therefore the flared extension is built into the toilet tank fig5 illustrates a.