Improvement of investment casting for the flange brake valve bush was approached. The key of design of the valve bush housing was provided including the corresponding technical measures through analyzing working state and its working structure. The determination of average dimension of mould design and control of key dimension of wax pattern were considered to make sure the qualification of casting dimension. The vertical ingate was adjusted to horizontal ones with strengthening rib in modified technical sketch

which can improve the dry condition among pattern assemble during shell making and radiator conditions of the poured valve bush

and shorten the feeding distance of gating/riser from hot spot in the valve bush to eliminate the shrinkage hole defects in the valve bush.