用锡青铜铸造的阀体及其他受压零件,如果熔铸方法不良,在水压试验时常常会发生漏水现象。其原因是由于锡青铜结晶时温度间隔很大,容易得到分散性的收缩,内部组织粗松,结果使铸件紧密性不佳,这种缺陷一般称为“发糠”。此外,由于铸件内部有气孔和砂眼等存在时,也同样会发生漏水现象。锡青铜铸件由于这些原因所造成的废品,在废品率中所占的比例相当大。根据苏联专家库次涅佐夫同志建议,如果将 Body cast bronze and other pressure parts, if the casting method is not good, often occur in the hydrostatic test water leakage. The reason for this is that the tin bronze crystallizes at a large temperature interval and is liable to disperse shrinkage. The internal structure is loose and as a result, the castings are poorly compacted. Such defects are generally referred to as “bran.” In addition, due to the presence of porosity and trachoma in the presence of casting, the same will happen leaking. Waste of tin bronze castings caused by these causes represents a considerable proportion of the rejects. According to the suggestion of Comrade Geniezov from the Soviet experts, if so,